Gas column Neva 4511 repair by own hands

Flow-through gas heaters - the columns become "rods" to provide the family with hot water in a private house or when the central hot water system in a high-rise building is not provided for or stable operation. Once the "undividedly ruled" in buildings of old construction, the columns at the time undeservedly "went into the shadows," but now, apparently, are experiencing a "second birth", as more and more homeowners are striving for complete autonomy, independence from "whims"communal services.

To meet the needs of consumers, all new water heaters have been developed and are constantly appearing, which are already very remotely reminiscent of their bulky predecessors. They are equipped with modern automation and multi-stage protection systems, which provides increased safety of operation of devices. One of the most successful models of domestic development is the Neva 4511.This column is small in size, sufficient for domestic needs, with performance and power, ease of use, and good reliability. However, any technique from time to time can present an unpleasant "surprise", refusing to turn on or work with various violations. The water heater is not an exception. And since it is one of the most massive, then search queries - the gas column of the Neva 4511 repair by one's own hands - are also found quite often.

Do not assume that this is a consequence of the poor quality of the product. Very often, a breach of the operating rules or neglect of the manufacturer's recommendations leads to this or that breakdown.

Installation of a gas flow-through water heater "Neva 4511"

First of all, it must be noted at once that it is not particularly recommended to undertake self-repair of the gas column, at least to those owners whogenerally little knowledge of such devices. Especially do not do this in the period of the unexpired warranty period - independent repair will terminate the obligations of the manufacturer.

However, the mentality of most of our men is that they need to be able to do everything with their own hands. This is facilitated at times by the slowness of service services, overly inflated prices for a specialist's call and other similar reasons. But if there is a desire to perform repair consistently, then it would be unwise to proceed to it without understanding the device of the column.

Information on the device and characteristics of the column "Neva 4511", of course, is contained in its technical description. However, the information still makes sense - for at least those who for some reason lost the passport of the product.

To begin with - the main characteristics of the water heater:

Parameter name	Parameter values ​​
Rated thermal output of the	column 21 kW
Rated heat output	18 kW
Efficiency, not less	0.87
Energy types used:	Natural gas network G20
Gas liquefied in cylinders G30
Required nominal gas pressure, kPa:
- natural G20	1.3( 2.0)
- liquefied G30	2.9
Average gas consumption for continuous operation:
- natural G20	2,22 m³ / h
- liquefied G30	1.66 kg / h
Diameter of replaceable torch nozzles:
- for network natural gas G20 with pressure 1.3 kPa	1.28 mm
- for network natural gas G20 with pressure 12,0 kPa	1, 14 mm
- for liquefied gas G30	0,79 mm
Minimum allowable water flow for correct operation of the	column 2,5 l / min
Operating pressure range in the cold water supply line	15 ÷ 1000 kPa
Average water flow at supplytemperature rise by 30 °( Δt = 30 °)	9,2 l / min
Water flow rate at loadΔt = 40 °	7 l / min
Heating water flow Δt = 25 °	11 l / min
Scope of required deflation in the flue duct	2,0 ÷ 30 Pa
Normal combustion products temperature	no higher than 150 ° C
Type of ignition of column	Electronic, automatic with water supply
Power supply	Two batteries with voltage 1,5 V, type V LR20
Average total operation time of the device on one set of batteries	250 hours
Overall dimensions of the heater( height × width ×LUBINA)	565 × 290 × 221
Mass of water heater( gross / net), maximum	11,0 / 10,0 kg

Now consider it from the outside:

column From the front and the sides, the column closesmetal enameled casing - lining( pos.1).Approximately in the center of the "facade" is a viewing window( item 2), which allows you to visually monitor the operation of the device.

Below are the controls. This is the throttle control knob( key 3) and the water flow crane handle that is symmetrical to it( key 4).Between them is a two-digit digital indicator( item 5) showing the current water temperature at the outlet of the column.

Three nozzles are located at the bottom, each with an external threaded section G ½.On the right( the nozzle( item 6) is intended for connection to the water supply system - for cold water supply. The leftmost branch pipe( item 7) is the outlet of the heated water, connected to the inter-apartment wiring of the hot water supply system. Closer to the center and slightly forward( position 8) - connection for connection to a gas main or to a cylinder with a liquefied gas

The gas nozzle outlet( pos.9) is connected to the top for connection to a chimney system

The entire column design is assembled on a metal console( key 10), which simultaneously acts as the rear wall of the instrument. There are two "windows"( item 11) for hanging the water heater on the wall on the hooks-brackets.

Now consider the column with the cover removed:

In the diagrams - "end-to-end" numbering, therefore the positions 6, 7 and 8 - respectively, the pipes for connection to the water supply, to the wiring and to the gas source.

The nozzle( key 6) is connected to the water block( key 12), which includes the water flow adjustment valve stem( key 13).Below you can see a cylindrical detail with a notch on the walls( item 14) - this is a plug for draining water from the column while carrying out maintenance and preventive works. It also provides an emergency valve, which operates when the pressure in the water supply system is exceeded.

The electronic control unit( item 16) is located centrally, from which wires lead to the sensors and functional elements of the device.

A gas block is positioned symmetrically to the water( key 17).They are assembled in a single construction - a water and gas unit. From the gas unit, the gas flow adjustment valve stem( key 18) emerges. An electromagnetic gas valve is installed between the inlet pipe and the tap( key 19).

In addition, the micro-switch( key 15) is fixed to the gas block, which is pressed by a special pusher when the position is switched off.

Above the water and gas unit, a gas manifold( item 20) is mounted, connected with it by a bent nozzle on the flange connection. The collector on the column body is fixed with two screws( item 21).

In the collector, nozzles with the required bore diameter are installed on the rear side to discharge the gas to the 10-burner( key 22).From the front side of the collector are fixed two elements, which are outwardly similar to each other, but perform completely different functions. On the right is a spark plug, for ignition of the column at start-up( key 23).On the left( item 24) is a flame sensor( often called an ionization sensor).

Above is a copper heat exchanger( key 25), where, in fact, the water is heated from the flame of the burner. The heat exchanger has detachable connections: on the right( key 26) - with the water unit of the device, and on the left( item 27) - with the outlet pipe for hot water. In addition, the heat exchanger is fixed to the housing with a pair of screws( key 28)

Two sensors are located at the outlet. The upper one( item 29) is the sensor for protecting the speaker from overheating( in fact, the thermostat), and the lower one( item 30) serves as a thermometer and is connected by a pair of wires to the display panel on the instrument case.

At the top of the column is a gas outlet( key 31), which has its own system of straight and curly bridges, directing the flow of hot combustion products in the right direction towards the chimney channel. On the left-hand side( key 32) there is a traction sensor, also a thermal relay, connected by one electrical circuit in series with the overheating sensor( key 29).

Below is the plastic battery compartment( key 34) for the two batteries.

And finally, from the bottom left and right, at the extreme points of the console housing, there are two brackets with eyelets( key 33), into which screws are screwed when installing the cover casing.

Many of the details and nodes will be considered in more detail during the publication with the image application. In this case, all numbering on the diagrams or photos will be saved.

Video: basic information on the gas column device "Neva 4511"

How the Neva 4511 gas column works

To understand how the water heater works and how it is equipped with protection systems, let's turn to one more scheme:

When the appliance is switched off, the control unit electronics( key 16) is not energized - it is open in the microswitch( key 15) located on the gas unit. The pusher presses the microswitch plate, keeping it in the "off" position.

If there is no supply in the closed position, there is also an electromagnetic gas valve( item 19) overlapping the gas supply from the inlet to the gas unit. In addition, the gas supply is closed at one more turn. This is a mechanical spring poppet valve located in the gas block( in the diagram - item 35).In the non-working position, the gasket of its plate is pressed tightly against the corresponding seat, completely closing the channel for gas passage to the collector side.

The main part of the water block( if you do not consider the adjustment valve) is the so-called "frog"( item 36) - a two-chamber device separated by an elastic rubber membrane. The cameras of the "frog" are communicated - a special channel is provided for this. When the water supply is turned off, the pressure in the chambers is lost, and the membrane occupies a free equilibrium position.

The water flow from the main to the heat exchanger is carried out through the lower chamber, and in the upper there is a movable rod with a plastic plate adjacent to the membrane. Stem through a special hole in the center outwards towards the gas block.

Accordingly, in the body of the gas block, the counter-shaft is exactly coaxially located, which is connected to a mechanical poppet valve, and the micro-switch pusher is attached to it.

What happens when the starts with cold water with the required flow rate( at least 2.5 liters per minute), that is, when a hot tap is opened at the hot water tap?

The flow of cold water passes through the "frog".The configuration of its internal channels is such that a vacuum is created in the upper chamber. The membrane under the pressure of the flow curves and pushes the plate, which imparts translational motion to the rod. This rod of the water assembly, in turn, presses the coaxial stem of the gas block, moving it( key 37).At the same time, two operations are performed simultaneously:

• The rod-connected pusher releases the microswitch plate and the switch goes to the "closed" position. The electronic circuit of the control unit receives power from the battery compartment( key 34).
• The stem movement ensures that the force of the clamping spring in the mechanical gas valve is overcome. His plate moves away from the saddle, opening a channel for the passage of gas to the collector.

With the power supply, the electronic control unit starts working:

• The voltage is applied to the solenoid valve, which opens the path of the gas from the inlet to the tap and further, through the mechanical valve - to the manifold and burners.
• The control unit generates and sends to the ignition plug( key 23) the pulses necessary to create spark discharges that cause ignition of the flame. If everything worked properly, the burner should catch fire.
• The ignition process is monitored by a flame sensor( ionisation)( key 24).If, for any reason, the burner is activated in the first 6-7 seconds, in order to avoid a free gas outlet and accumulation of an explosive concentration, the control unit will close the solenoid valve and stop the pulses from being applied to the spark plug. If the ignition is successful, the signal from the flame sensor will be converted to a command to stop sparking on the spark plug. During the operation of the water heater, if the flame suddenly goes out, the absence of a signal from the ionization sensor will close the solenoid valve.

All these functions will be performed under one more condition - if the circuit is not broken, which includes two temperature sensors - thrusts( key 32) and outlet water temperatures( key 29).The normal position of these relays is closed, they are arranged in series, which means that the control unit will receive power only if both sensors are in normal operation.

• If the draft is not sufficient in the chimney, the exhaust gases do not pass directly to the central channel, but, due to the special configuration of the device, they enter the lateral cavities. On the left there is a sensor that immediately reacts to an abnormal temperature rise and will open the power supply circuit of the control unit with all the ensuing consequences.
• The relay placed on the outlet pipe from the heat exchanger will arrive in the same way. If the temperature reaches the critical ceiling( of the order of 90 ° C), then the supply circuit of the control unit opens.

With the shutdown of the , the following occurs:

• The absence of water pressure leads to a rapid equalization of the pressure level in both chambers of the "frog".The membrane returns to its original position, ceasing to transmit the effect on the plate with the stem. Accordingly, the stem of the gas block under the action of the springs also returns to its place.
• The stem return releases the poppet valve, which tightly closes the gas passage.
• The push rod presses the microswitch plate, and the power supply circuit of the control unit is broken.
• The power supply does not transmit voltage to the solenoid valve from the unit, and it goes to the "closed" position.

All, by closing the cold water supply, the column in automatic mode is completely turned off.

For clarity of the picture, you can bring the view of the column from below - the photo clearly shows the main parts and components that directly affect the operation of the column( numbering is saved).Added position 40 - pusher microswitch.

The indicator circuit is also activated in the electronic circuit of the column( key 38).It is connected by a pair of wires to the control unit - to obtain the necessary power supply, and to the output temperature sensor( key 39).However, this device plays only an informational role, taking no part in the adjustment and performing no protective functions. The column remains operative even if the display circuit is completely disconnected, for example, when removing the upper cladding.

Such a detailed story about the device and the principles of operation of all nodes and mechanisms of the column is necessary. If the owner of the device is well versed in these issues, then, most likely, it will even be intuitively easier for him to understand the possible cause of the appeared malfunction and the way to eliminate it.

Well, now you can go right to the most common problems and assess whether they can be fixed on their own.

How to troubleshoot the Neva 4511 column

power supply problem As can be seen from the description of the operation principle of the Neva 4511 column, the normal operation of most nodes requires a stable power supply.(an exception is only a disc-shaped mechanical gas valve).So, if the water heater refuses to work properly - does not light up or goes dead after a while, then the problem can be quite simple - it lacks the power supplied from the current cells.

Often inexperienced users can be fooled by the fact that the digital scoreboard is on fire, and it would seem that there is no problem with the power supply. But. It should also be taken into account that a fairly large charge is expended on the pulses transmitted to the glow plug. In addition, the control unit transmits a constant eclectic signal to the solenoid valve, keeping it in the open state. And the total energy consumption can thus exceed the capacity of the battery.

Sometimes you can find on the Internet complaints of the owners that, they say, they checked the battery with a tester - and it shows 1.5 Volts, as expected. Or, for testing, put it in a flashlight - and it burns. Both of these things do not at all indicate the complete working capacity of these batteries. The voltage at the contacts can be normal, and the current under the load is insufficient. A momentary switching on the lamp is one thing, and a constant stable current during operation, and even simultaneously with the work of the spark plug at the time of starting up, is completely different.

In a word, if there is a problem with such a plan and there are no other apparent reasons, you should replace the batteries with guaranteedly charged ones( in general, it will be superfluous to have a spare kit at hand).

The manufacturer indicates in the technical documentation the possible duration of continuous operation on one set of batteries - the value is very approximate, which depends on the quality of the batteries, and on the features of the operating conditions of the water heater. Please note that it is recommended to use batteries type LR20 - this means that they must be alkaline( alkaline).Cheap salt( R20) a priori can not cope with the constant load and fail extremely quickly.

	The whole sequence of work will be shown on the column that lies on the table( just as an example).This does not change the order of the operations performed. The drawings show the water heater "Neva-5611", but its lining and almost all the internal structure exactly corresponds to the device 4511. There is a small nuance in the casing attachment, which will be mentioned. The first thing to do is remove the crane handles - just gently pull themselves. There are no locking fasteners on them. Rotate them, too, do not. The handle is removed first from one tap,. ..
	. .. and then from the second. If the handle "resists", does not want to go off the rod, you can slightly push it from below, pushing your hand under the lining.
	Here it is - the only difference in the cladding fastening on the column "Neva 5611": under the handle of the gas supply control valve there is a fixing screw, which must be unscrewed with a screwdriver. On models 4511, there is no such detail, and this step is simply skipped.
	There is a temperature indicator on the lining, from which two pairs of wires exit. The blue-black pair goes to the temperature sensor, the red-black pair goes to the electronic control unit.
	The wires are provided with connecting pads, which must be simply opened by slightly pressing the plastic lock. First, one pair is disconnected,. ..
	. .., then, in the same way, the second one.
	As already mentioned, this indicator plays no role, except informative, and its deactivation does not affect the course of further repair and preventive works, and the column at the same time remains fully operational.
	The fixing screws-self-tapping screws, which hold the cover on the console from the bottom, are rotated one by one. On the hanging column they are located in the lower extreme points of contact of the apparatus to the wall.
	Screws from both sides self-tapping while removed to the side, but so as not to lose them.
	The fingers of the hands are set underneath under the lining, and to begin with, it is slightly pushed towards itself - with special centering semicircular spikes coming out of the casing holes on the console frame.
	Then it only remains to feed the casing up - and it will come off the bracket-hooks of the console. Experienced masters advise in performing this simple operation, however, be cautious - often poorly worked edges of the metal sheet, from which the lining is made, are able to cut the skin of the palm or fingers to the blood.
	Everything, the casing is removed, and it can be put aside. In the picture, slit-like holes are clearly visible, into which hooks-hooks of the console enter.
	And in this figure the central locking hole is shown( with a green arrow), and a mounting platform with a hole through which the screw is screwed( blue arrow). The same elements are located on the opposite side of the
	as well. The picture shows an electronic indicator at the rear with two pairs of wires coming out of it.
	Reassemble in reverse order. First, carefully put the casing slit hole on the hook of the console with one. ..
	. .. and on the other side of the device.
	Then the lining is fed slightly downwards( it can itself sit under its own weight), so that the centering protrusions get into the locking holes. This is done carefully, as the facing in the removed form is somewhat unstable, its walls spring. As a result, the holes for screwing the screws must be aligned at the bottom. The fixing elements are screwed into place.
	The next step is the connection of the terminal blocks of the pairs of wires from the electronic display. You do not have to be afraid of mistakes - in addition to color marking, the configuration of the shoes themselves is such that it is simply impossible to mix up the contacts. And lastly, on the ends of the rods of both cranes that come in over the facing, arms are put on, red on the left, blue on the right. Great efforts at this is not attached - in the handle nest there is a slot, exactly corresponding to the "geometry" of the rod.
Illustration	Brief description of the operation

It's even better, of course, to purchase lithium batteries( CR20).They are distinguished by high capacitance, stability of the generated current, duration of use, which can exceed the service life of alkaline ones by several times. The only thing that can be put in a "minus" is a very high price, and it is not so easy to find them. So from the standpoint of economy and profitability, the optimal solution is the working set of quality LR20 in the water heater, and one more, new, in the original packaging - in stock.

You should never purchase such batteries in "incomprehensible" retail outlets, in street kiosks or from market stalls, especially in the cold season. Incorrect storage conditions can easily lead to the fact that batteries with a valid, seemingly validity, are suddenly unsuitable for use. It is better to give a little more, but to buy really high-quality items in a specialized store, where the seller-consultant can also check the voltage and discharge current for them.

Replacement of batteries - the only, perhaps, "repair and recovery operation" on the column "Neva 4511", which can be carried out without removing the cover-casing. Access to the battery compartment is open from the bottom - you just need to turn the locking flywheel. Be sure to check the polarity of the installation of the elements.

And one more nuance. The column is still operated in a condition of high humidity, therefore it is recommended to regularly check the cleanliness of the contacts in the battery compartment - their petals can be covered with corrosive or chemical attack, and there can not be a quality power supply even with guaranteed performance of the elements. This, by the way, judging by the statistics of the applications of the owners of water heaters, one of the most common causes of the so-called "breakdown" of the water heater.

All further cases of inoperability of the water heater will be considered from the standpoint that there is no guarantee of power supply problems.

Removing the Neva-4511 Column Lining

Any other work, other than replacing the batteries, will require the removal of the lining of the column. It is not difficult to do this, just like installing the casing back into place.

When dismantling the casing, and any other repair work, the cranes on the water supply and discharge pipes and on the gas pipe must necessarily overlap. Then the following actions are performed:

The process of installing the cladding was considered immediately, so that these questions no longer come back.

Repair work on the water knot of the column "Neva-4511"

The most frequently encountered in the course of operation, the breakdown of the column is due to the breakdown or failure of the components of the water node. In describing the principle of operation, it has already been mentioned that the water pressure acting on the membrane and transferring the force further to the gas unit opens the mechanical gas valve and turns on the power of the entire control unit. Naturally, if this mechanism fails, the column will simply not be turned on.

A water node malfunction can often be seen and visually observed. When starting the water, you need to pay attention to the pusher, which pushes the microswitch plate. If it remains stationary or just slightly twitching - this is a clear sign that the membrane in the "frog" is broken( in the picture below it is shown with a blue arrow).The absence of movement can also be caused by the boiling of the rod. In addition, the emergency condition of the water node can be expressed in the appearance of leakage at the point of its connection with the gas unit or on the tap of the water flow adjustment( typical places of water appearing are indicated by red arrows).In any case, the node must be removed and disassembled for recovery.

The water assembly can only be removed with the gas. This is done as follows:

a - after checking that the gas supply valve on the pipe is closed, the flexible hose is twisted.

b - similarly, after the main line is closed, the cold water supply is removed from the branch pipe.

in - the wrench unscrews the connection of the water unit with the copper pipe leading to the column heat exchanger.

- opens the terminal block on the wires going from the control unit to the solenoid gas valve.

	The removed water-gas knot lies on the table. To begin with, it needs to be divided into two blocks - water and gas.
	To do this, the two screws shown in the photo are turned off by the stacks. You can not twist them up to the end - they simply clamp the cylindrical protrusion of the "frog" in the socket of the gas block. The screws are located diametrically opposite, from above and from below. There is a nuance - they usually have both slots for a figured screwdriver, and a hexagonal bonnet. If there is a packing head - it is better to use it. Often at this point the steel screws will turn sour in the silumin case of the gas block, and it is difficult to erect them from their place. Sometimes it makes sense to pre-process the WD-40 junction, as the mass of cases where the screws in this place break off from too much applied force, effort, and the slot for the screwdriver simply "lick".
	The screws loosened from both sides "released" the water block.
	Here it is - separated from the gas. In these photos, everything looks beautiful, in the factory grease, but this is not always the case - the example will be given below.
	Next, the "frog" itself needs to be disassembled to get to the main membrane node. Six screws in a circle are twisted. They can also be "acidified", so we work cautiously not to "lick" the heads.
	After removing the screws, the unit will open in two parts. Immediately visible rubber membrane. Very often it is its break that leads to the complete inoperability of the entire column.
	We carefully inspect the membrane. If it is excessively stretched, there are gusts or even "hints" on the integrity violation - a new one is acquired. No glueing the case will not help.
	Remove the membrane to get to the spring-loaded plate with the rod, which transfers the translational motion to the gas block. If the membrane is whole, then remove it carefully, to prevent the tear in the place where it is put on the pipe connecting the upper and lower chambers of the "frog"( pictured above with an arrow). By the way, this tiny branch pipe is removable, and you need to make sure that it does not accidentally roll up somewhere. Without it, the "frog" will not work correctly.
	The upper chamber of the unit with a spring loaded plate connected to the
	rod Gently pull out the plate so that the rod exits the guide channel.
	Remove the spring, and see below the plug with a slot for a straight screwdriver. There is a seal that prevents the water from the upper chamber of the frog from escaping to the gas block. It also requires periodic inspection, lubrication, tightening or replacing the gland rubber ring.
	We purchase a repair kit - a membrane and a sealing ring. They are inexpensive and do not usually have a deficit. Further assembly of the unit is performed in the reverse order. When installing the oil seal, the socket and the ring itself should be lubricated with silicone grease. The plug is tightened with such force that the inserted rod does not clinch, could move freely enough, with moderate force application, to move along the channel. When installing the rod do not forget to put in place, under the plate, the spring.
	The membrane is sealed with a hole on the inserted branch pipe and neatly placed in the body of the "frog", so that its edges at the edges lie exactly in the socket-groove. Then we collect both halves of the block and twist the six screws. If there were steel ones, it's better to replace them with bronze ones at once - they will last longer, and subsequent membrane changes will still be easier. After that the repair of the "frog" can be considered complete - it is possible to connect the water and gas blocks into a single unit, install them in a column, make the necessary connections and check the operation of the water heater.
	The importance of quality sealing on the stem can be clearly demonstrated by an example. Water flowing through the stuffing box got into the socket of the gas block, caused a massive deposition of scale, disabling the microswitch. Partial jamming of the gas valve stem has occurred. In addition, during dismantling, one sour stop screw broke and the cylinder wall of the gas block collapsed - it will have to be changed.
	Repair of the water block is also somewhat complicated. Completely overgrown with a scum lid frog had to soak in a solution of soda. ..
	. .. and then carefully cleaned of plaque.
	When screwing the frog screws, it is recommended to densely coat them with graphite or other water-resistant grease.
	All troubles due to the fact that the owner "ran" the water heater, did not check the quality of the seals on the water block. And now such a tiny detail, having developed its resource and poistershis, has entailed such serious consequences. Conclusion - the slightest signs of the appearance of moisture in the junction of the gas and water blocks should be immediately suppressed.
	To finish with the water block, let's look at one more place of possible leakage of water - from under the stem of the control valve. It happens, it's not often, but still. The tap itself is fixed in the water block socket with just one screw( shown by an arrow).
	We unscrew the locking screw and pull up the valve stem. The cylinder with figured apertures is located at the bottom, which regulate the intensity of the water flow. And above - there is an annular gasket( shown by an arrow).Leakage from the tap is a consequence of its wear or tear. Changing the gasket should completely solve the problem.
Illustration	Brief description of the operation

	Before us - the gas block assembly, already separated from the water. Before removing it from the column, if there was a smell of gas or if there was a characteristic noise, it is advisable to localize the leakage spot - cover all the matings with a dense soap foam. The appearance of bubbles will show a leak.
	Sometimes a column failure is caused by the failure of a solenoid valve - it simply does not allow gas to flow to the reducer and burners. The valve is mounted on the landing pad with two screws, and has two more centering protrusions, so you can not make a mistake when reinstalling. Screws are screwed with a screwdriver. This screw connection, by the way, causes a lot of criticism of the masters, because of the poor quality of the fasteners. If possible, both screws should be replaced at once with better quality ones, with powerful heads for a shaped screwdriver.
	The valve is removed. Pay attention to the saddle of the unit in which it is installed - there is laid an annular gasket sealing this unit( shown by an arrow). On the most movable spring-loaded valve stem is an elastic "plug", which breaks in the non-working position the gas passage channel is higher. Neither on the gasket, nor on this "cork" should there be no signs of wear.
	Three wires are suitable for the valve: black, yellow and red, which are connected to the control unit via the terminal block. For smooth ignition of the water heater at the moment of startup, the power is transmitted to the pair black( mass, minus) - yellow, and the valve opens slightly. After ignition, the power is supplied through the red wire and the valve opens completely. It is not difficult to check the valve's functionality - this is done even with the water-gas unit installed in the column, power supply, but with the water and gas connections closed or even disconnected. It is only necessary to unscrew and remove the valve carefully, leaving it connected with the control unit. Then it is necessary to "deceive" the control of the device - manually move the pusher at the microswitch. The control unit "thinks" that the water supply has been made and will transmit a control signal to the valve - it must retract the rod with the plug and hold it in this position until the "micro" is released( the pusher is released). Simultaneously sparking must occur on the spark plug( with a characteristic sound). If the valve does not give signs of life in such conditions, then it will have to be changed to a new one - it is easy to acquire it.
	The gas flow adjustment valve, in complete analogy with the water, is fixed with one screw,. ..
	. .. and the seal is the same - the O-ring gasket( shown by the arrow). If a gas leak from here, then just change this seal.
	Now deal with the microswitch - it happens that it breaks down due to the ingress of water into it. Check - it's quite simple: you need to ring it in both positions. Without the use of any external forces, the pusher presses the plate against the microswitch, the button is depressed, the circuit is open, no power is supplied to the control unit.
	If push the inside of the stem( shown by the arrow) of the gas block( which is what the "frog" rod does when starting), the pusher releases the plate, the button rises, the electric circuit closes.
	If the microswitch does not work, it must be replaced. It is fastened by two screws, its dismantling and installation of a new labor will not be made. However, one need to make one remark. The pusher is a cylindrical rod that is fixed to the thread on the stem of the gas block. On the top there is a slot for a straight screwdriver. It happens that a poorly tightened or incorrectly exposed pusher, returning to its original position when the water is blocked, does not fully press the microswitch plate, and the button does not work to interrupt the circuit. It turns out that the board unit still "believes" that the device is in the working position, and this, in turn, is fraught with abnormal situations. When assembling the water-gas unit, this moment is taken into account - the pusher is set in the desired position and tightened tightly with a screwdriver.
	Continue disassembling the gas unit - unscrew the two screws holding the assembled mechanical gas valve assembly.
	Carefully disconnect the two halves of the housing so that the valve spring does not spring out of the way.
	We get the poppet valve and a thin ring-shaped gasket. We assess the integrity and degree of wear of seals and springs.
	The "plate" of the valve with its sealing belt must be pressed against the seat( green arrow) and should not be bruised or deformed. The red arrow shows the rod that transmits force from the water assembly and opens the valve.
	The free stroke of this rod is checked in one direction and the other. By the way, you should immediately evaluate whether there are signs of water ingress or gas breakthrough in the opposite direction. Here, the stem also has a stuffing box seal, which, if it turns out, can be changed. Sometimes you can not unscrew it, and you have to change the entire assembly.
	All, the dismantling of the gas unit is completed. It is possible to go through the revision and cleaning field to the assembly, performed strictly in the reverse order. At the same time, worn parts are replaced as required. After the final assembly of the column, all connections are checked for leaks, as well, by soaping under gas supply conditions.
Illustration	Brief description of the operation

D - then the wires going to the microswitch are also disconnected in exactly the same way.

e - a powerful figured screwdriver, two screws of the flange connection of the water and gas unit with a branch pipe that transfers gas to the burner manifold are twisted.

After that, the whole water-gas unit is easy to pull out carefully.

Next, proceed to disassemble and repair:

Prevention or repair of the gas block

Problems in the gas block happen much less often, but still not completely excluded. They can be manifested by the lack of gas flow to the burners, the smell of leaked gas, and in the event of a breakdown of the microswitch, which is also placed on this block, the complete inoperability of the entire column.

Below in the table, the gas block removal procedure will be shown. Stages will be accompanied by comments that from parts or mechanisms can cause abnormal operation.

Important note! If, after turning off the water, the column continues to burn, then this is an obvious jamming of the rods in the water or gas block. It should immediately turn off the gas supply, and then disassemble and repair these units.

Problems with ignition and electronics

1. One of the most common problems - the column is not lit after opening the hot water tap. At the same time, the pressure goes normal, the water block is triggered normally, the control unit is turned on, the gas valves( both electromagnetic and mechanical) are clearly open, as it is audible and smelled that the gas enters the burner.

The most common problem is that the candle does not give a qualitative spark to the flow of the gas-air mixture. And this, in turn, can be caused by several reasons.

• First, the spark can not beat right there or be too weak because the glow plug contact is misplaced, shifted. For normal operation, the electrode should be located 5 mm( tolerance no more than ± 0.5 mm) from the burner nozzle guide, exactly in the center of the section.

You can adjust the position if you slightly bend the electrode, achieving a qualitative spark. Alternatively, loosen the screws on the clamping plate, fix the casing of the spark plug insulator, and then re-tighten the fasteners.

clamping plate. At the same time, it is necessary to immediately clean the surface of the electrode - it could form a deposit, and there is no qualitative discharge. You can use fine-grained sandpaper, but do not clean with a sharp object.

In parallel with this operation, similar actions can also be performed with the ionization sensor( flame).Its electrode should also be located in the center of the burner section, so as to be in the flame tongue when the column is operating. The surface of the electrode must also be maintained in a clean, not smoked condition. If the sensor "does not understand" due to an unsatisfactory state or an incorrect electrode position that the burner is working, then after seven seconds the control unit will simply close the electromagnetic gas valve and the column will go out.

• Secondly, there may be insufficient contact between the electrode and the high-voltage cable. To check, remove both cables - they are simply pulled down from the insulator casings. There will be seen a rod - a needle, through which the electrode is contacted with a conductive cable. It is necessary to check the condition of this needle - there should be no plaque on it that violates the reliability of the contact. After stripping, the cables are tightly inserted into the place in the insulators - on the right - ignition, with red markings, on the left - from the ionization sensor, with blue markings.

If the ends of the wires are heavily "wet", then you can cut them a little, but only in such a way that the length is enough for commutation, not a stretch.

• Thirdly, discharge to the case of the column can occur. It is audible that there is sparking, but not a spark or a very "dull" one, or it is not visible at all. The reason can be covered by a crack on the insulator of a candle - it must be removed, inspected, and if such a defect is detected, then the candle will have to be changed. Breakdown to the case happens at the output of the high-voltage cable from the control unit - this place is covered with foil, and such a breakdown is not so easy to notice.

mass. Here, you can try to insulate the cable from the top by using a thick shrink tube or even an electrical tape in several layers. It is possible that the problem will disappear after this.

. If this insulation does not help, and the casing can not be removed from the cable, you will have to change the control unit.

By the way, problems with spark, when it improperly beats or is too weak, provoke and one more "ailment" of the column - ignition occurs explosively, with loud clap. The dangerous concentration of gas accumulates in the combustion chamber, which leads to this effect. Elimination of flaws with sparking should also save this shortcoming.

2. The column may not turn on due to a malfunction of the traction sensors and the outlet water temperature. It has already been said that they stand consistently in the same chain, and the failure of even one of them will break this chain, respectively, thus preventing the control unit from operating.

The sensors can be checked by a dial or by an exception method. When tested with an ohmmeter, the operating sensor should show almost total conductivity( resistance close to 0 Ω).To check from the sensors, the tabs are removed - at the same time, the status of the contacts can be checked, since it is possible that they are simply "sour" and require cleaning.

If there is no multimeter, then you can do otherwise. The sensors are alternately put temporary jumpers, closing them directly. For example, the thrust sensor is reconnected, and the column is tried to start. If it is ignited then this is free - the reason is found, the sensor requires replacement.

If the jumper on the sensor does not give anything, it is removed and put on the second - temperature. The test is carried out in the same way.

IMPORTANT: if the column has been working with the jumpers, this does not mean that it can be left that way. Such testing is performed solely for the purpose of detecting a malfunction and only when the water heater is briefly started. Operate the column with a shorted safety chain - is strictly prohibited!

A few words about this security chain.

The cause of a quick turn-off of the column after a normal start may be a failure of the thrust - the upper sensor in this circuit at a temperature of about 75 to 80 degrees opens. Sometimes this phenomenon is caused by improper installation of the combustion products exhaust pipe. The table below shows common cases when an incorrect installation does not allow the column to work in its normal mode.

Illustration	Short description
Correct installation
	The diagram shows the parameters of the correct installation of the flue gas system.
Incorrect installation of
	A common mistake is that the pipe is embedded in such a way that it either almost touches the back wall of the chimney channel or overlaps a large sectional area. The required thrust will not be.
	At the same level as the installed pipe from the column, there is a ventilation window or connection of another device.
	Padded pipe is used together to connect another device, including a kitchen hood. The required discharge in the flue gas duct of the column will not be.

Elimination of flue installation errors should normalize the thrust, and the malfunction of the water heater will stop.

The lower temperature sensor can be activated if the water and gas flow rate is incorrect. The correct adjustment of the cranes can be eliminated by reducing the gas supply and increasing the water pressure.

Well, if the tested, guaranteed working elements of the power supply, the microswitch, which is clearly triggered when the water is started, tested, by default, a closed security circuit, but the column still does not turn on - you will most likely need to replace its "brains" - the control unit.

To finish the topic of electronics - another possible problem that does not directly affect the performance of the column, but introduces some discomfort during its operation.

This is a problem with the digital display on the front panel, although the column itself works properly.

• So, the dial can not burn at all - it means that it is necessary to check the reliability of its contact connection with the temperature sensor and with the control unit. If these measures do not change anything - then there is a failure of the display itself - it will have to be changed.
• If after the start-up, the numbers are replaced with the error symbols "EE", then the problem should be sought in the temperature sensor. It is also possible to either jam the contacts, or the total output of the sensor is out of order.

Problems with the

burner The column can be switched on and operated normally, but the required heating level can not be reached. It happens that the device starts to "smoke", and the flames of the flame on the burners are uncharacteristic blue, but with an obvious yellowness, unstable. It also happens that one of the series-sections does not burn at all. All this is the consequence of the clogging of the burner with dust, the overgrowth of nozzles of nozzles on the collector.

To clean the burner, it must be removed. This does not require the dismantling of the water-gas unit - it is enough to disconnect the wires from the spark plug insulators and the flame sensor, and then unscrew the union nut on the L-shaped branch pipe from the manifold to the gas block( shown in the photo with a red arrow).

Next, twist the two screws( shown in blue arrows) and remove the manifold itself. Then, two more screws( green arrow) will remain to unscrew the burner block.

At first, dust is removed from all parts with a brush. Dust must be cleaned and each internal channel of the burner - for this use a plastic ruff of the desired diameter. Then dilute the soap solution( you can - kitchen detergent) and they wash the burner both outside and inside, using a brush and ruff. After this, it is thoroughly rinsed with clean water and left to dry completely.

The collector is also first cleaned from above by dust and plaque with a damp cloth. Assess the condition of nozzles jets. It is impossible to clean them with solid objects( wire, knitting needle, etc.).It is better to unscrew them( head to 8), and blow it with a stream of air, for example, by a car pump. If the owner is a motorist, then he may have an aerosol in the garage for washing the channels of the carburetor: in this case such a solution can be very useful.

After cleaning, the collector is dried, collected, and then installed together with the burner back into the column. When installing, always check the condition of the gasket in the union nut.

Preventive work with heat exchanger

Problems with the heat exchanger are usually expressed in insufficient pressure at the outlet of the column, weak heating of water, suspicious noise during the operation of the column. Copper tubes of the heat exchanger can overgrow over time with scum, especially if there is hard water in the water pipe, and this affects both heat transfer efficiency and throughput. It happens that a heavily clogged heat exchanger does not allow the water node to function properly - that is not enough pressure, and the whole column becomes inoperative.

In addition, the normal heating of water can interfere with dust, mixed with soot, which clogs the space between the heat exchanger plates.

It is not difficult to remove the heat exchanger. The column should be disconnected from the water pipe, the remaining water is drained from it - the cork under the water block is twisted. Then, the nuts of the heat exchanger connections are loosened with the tubes coming from the water block and to the hot water outlet - left and right( in the figure are shown by green arrows).There are gaskets that are likely to require replacement.

You can completely release the heat exchanger after unscrewing the two screws( blue arrows) and removing the metal plate fixing it( yellow arrow).

• To clean the heat exchanger from the outside, it is first rinsed with a strong water jet and then immersed in a solution of detergent composition with degreasing properties( kitchen utensil suitable).This soak lasts 15-20 minutes at room temperature. Further, it is possible to clean all surfaces using a soft brush. After cleaning, the heat exchanger is abundantly rinsed with cold water. If necessary, the external cleaning procedure can be repeated.

• The internal channels of the heat exchanger are cleaned by flushing with reverse water flow under a high head. But if the build-up of scale is large, then a more complicated procedure is required, using an acid solution.

For these purposes, do not look for any technical acid - usually quite enough lemon. A solution is prepared from a ratio of 100 g of crystalline acid per liter of water at a temperature of about 35-40 ° C.

is perfectly suitable. This solution fills the whole cavity of the heat exchanger pipes through one of the nozzles. Usually, at the time of filling, in just a few seconds, the beginning of a violent reaction with the release of gas bubbles and turbid liquid is noticeable. Pipes are filled "under the string" and leave for about a quarter of an hour. After that, the remaining solution is drained and the heat exchanger is thoroughly flushed.

Sometimes, to achieve the optimal result, you need to repeat this operation.

After flushing the heat exchanger, it is installed into place. When connecting its branches with copper pipes, lay new rubber gaskets ½ inch. Too much pulling these connections is not necessary - the gasket can be transmitted, make a "skirt" inside the channel, and this causes unpleasant noise and even the place of possible clogging.

So, we considered the device of the column "Neva - 4511" and the most characteristic failures or breakdowns for it. Having disassembled in principle the operation of the water heater and the interconnection of all the nodes, knowing the technique of eliminating the main defects, the owner will be able to understand the likely cause of the malfunction and determine the scope of repair work. However, if there is no confidence in their own capabilities, it is better to invite a specialist, since the gas equipment of the amateurish approach does not tolerate.