Poor water heater performance interferes with normal life, doesn't it? The water barely flows or takes a long time to heat up, the burner slightly smolders or soot falls... You need to somehow fix it, find a repairman, negotiate on prices and terms. Why spend money if you can easily clean the heater yourself?
We will tell you how to clean a Bosch geyser with your own hands without contacting a gas specialist. To completely disassemble and clean the device, a “home” set of tools is sufficient. You will learn everything about dismantling the working units of the column, the rules for cleaning its burner, heat exchanger and chimney from the article we have proposed.
What pollutes a Bosch gas water heater?
The reasons for contamination of a flow-through water heating device are related to its functions and operating principle:
- Flowing water supply. The column heats the water flowing through its heat exchanger, which brings with it mineral inclusions. As a result, clogging deposits settle on the walls of the heat exchanger and pipes of the device and gradually increase.
- Burning gas burner . In case of incomplete combustion of gas (see reasons below), carbon deposits and soot are formed. The latter clogs the fins of the heat exchanger and the chimney, further impairing the combustion of gas fuel and slowing down the heating of water.
- Low quality tap water. Due to the hardness of tap water, when it is heated, salts are released from the composition, which are deposited in the form of scale inside the pipes and heat exchanger. The thicker the layer of scale, the narrower the lumen of the pipe and the worse it passes water.
In addition to magnesium and calcium salts dissolved in water, it contains mechanical impurities from rusting pipes. They also participate in the gradual growth of the pipe channel in the heat exchanger together with scale.
As for soot, its active formation is facilitated by increased pressure on the burner, weak chimney draft (low height, cracks, lack of thermal insulation, etc.), lack of supply air (PVC windows are sealed, but there is no supply valve).
Soot deposition is also facilitated by the use of forced exhaust in a room with a working water heater (causes a lack of oxygen), dustiness of the room (dust enters the burner, due to which complete combustion of the gas does not occur).
Filters and magnetic traps, fine adjustment of the burner and air draft will slow down the process of column clogging, but will not completely eliminate it
Since scale formation is more intense when water is heated above 60°C, some owners of German water heaters set the burner heating temperature to low. However, as a result of this, the working cavities of the heat exchanger gradually become overgrown with a greenish coating from condensate.
As a result, the removal of flue gases deteriorates, which contributes to the accelerated formation of soot. A heat exchanger clogged with soot heats water very poorly - soot is a good heat insulator.
When cleaning is necessary
A gas boiler is a complex device, and disassembling it without a good reason is too expensive. To avoid taking unnecessary actions that could cost you a pretty penny, check out a number of signs that indicate a clogged heating element:
- The boiler does not produce the required amount of heat, while consuming a large amount of fuel.
- During operation of the device, extraneous noise appears, the presence of which was not observed before.
- The water pressure from the tap decreases significantly.
- The heating process of the batteries is slower than usual.
Gas consumption has increased
One of the key reasons why gas consumption increases significantly compared to the norm is the clogging of the heat exchanger with scale. The boiler requires more fuel to heat the exchanger to the required level. After cleaning the part, the consumption returns to the basic values.
Burner always on
A clogged heat exchanger means that the water takes a long time to heat up, and the turbine constantly pumps in new liquid.
Because of this, the burner is constantly working, trying to bring the water temperature to the required value.
Descaling solves the problem, allowing the boiler to operate normally, without interruptions.
Rumble and interruptions in the operation of the circulation pump
A clogged system makes it difficult for fluid to circulate, causing the pump to overload during operation. Because of this, the following appear:
- extraneous noise;
- interruptions in the operation of the device;
- engine overheating.
Reduced pressure in the DHW circuit
A decrease in pressure in the DHW circuit is possible due to:
- incorrect operation of the heat exchanger;
- leaks in the pipeline system;
- The hot water supply circuit is depressurized.
Note! The above symptoms can occur not only due to the boiler being clogged with scale. This should be taken into account when diagnosing a fault.
Signs of a clogged gas water heater
The need to clean a Bosch flow-through gas water heater is determined by a decrease in the performance of the device.
Cleaning is required if:
- the water heater simply does not start;
- it turns on, but does not work for long and turns off on its own, while there is no shortage of water or gas;
- the heater heats properly, but the water heats up noticeably worse than before;
- the water pressure at the outlet of the heating device is weaker than at the inlet to the heat exchanger;
- Frequent operation of the overheating sensor, although the water heater is operating under average load.
Ignition jet is clogged . It is impossible or difficult to ignite the column if the igniter nozzle is clogged, which is why the device ignites the fuel with a delay - with a characteristic pop. A sign that the igniter is dirty is a weak yellow wick flame, although it should be blue.
Soot in the chimney. If the burner flares up but goes out almost immediately after ignition, the smoke duct of the water heater is dirty. The permeability of the chimney is significantly reduced due to soot and soot deposits that have accumulated over the years of using the dispenser. However, the chimney of water heaters in apartments is more often contaminated with flying debris.
Preventive cleaning of a gas water heater must be carried out regularly, the recommended frequency is every two years. Otherwise, the dispenser will work worse and worse, wasting natural gas and water aimlessly
Weak air flow. For natural draft, even a small gas water heater requires supply air. And modern homes are equipped with airtight window and interior door units.
The problem of insufficient draft can be solved by ventilation valves built into window frames, wall inlets, as well as ventilation grilles in interior doors.
Scale in the heat exchanger. Insufficient heating of water in a flow-through gas heater causes a reduced flow area of the heat exchanger pipe caused by a layer of scale. And the more scale builds up, the lower the water pressure after heating in the column against the background of normal pressure at the inlet to the heating device.
Overgrowing of the heat exchanger with soot. The largest amount of soot accumulates in the central part of the finned heat exchanger, transferring heat to flowing water and contributing to overheating of the side sections of the heat exchanger block.
Uneven heating of the heat exchanger causes rapid response of the overheating sensor. Most often, contamination of the fins with soot develops together with a clogged chimney.
Mechanical and chemical cleaning of boilers
Gas boilers can be cleaned in two ways: chemical and mechanical.
Before you start cleaning, you need to stock up on all the tools necessary for the job. You will need: scrapers, brushes, scrapers, screwdriver, gloves.
Chemical flushing of boilers is becoming more popular because... This process is quite simple and not time-consuming. To descale a gas boiler, you need to heat the reagent to the desired temperature.
Then use a special pump to pump it into the boiler system. The reagent will enter into a chemical reaction with scale and all kinds of deposits.
The following reagents can be used: adipic acid, sulfamic acid and gel.
Adipic acid must be diluted with water and poured into a cooled boiler using a pump. Then you need to release the pressure and wait until the acidic salts precipitate. It will need to be washed off with water.
Sulfamic acid is diluted with water in a separate container, and then pumped under pressure into a gas boiler. Next, you will need to wait a while, rinse the boiler and dry it.
Be careful! Any substance contains unsafe chemical solvents, so follow safety rules and clean the gas boiler using protective gloves.
The gel is not an acid, but it is well suited for descaling boilers. This substance allows you to clean the boiler carefully, it does not damage its walls.
How to remove the casing of a Bosch water heater?
The decorative and protective casing of the speaker is easy to remove:
- you need to unfasten the round adjustment knobs by pulling them towards you;
- move the rectangular gas adjustment knob to the body cavity (the “ignition” position). Please note that not every Bosch water heater model has such a handle;
- Using a Phillips screwdriver, unscrew the two self-tapping screws securing the casing to the column frame. They are located at the bottom, on the sides of the device.
All that remains is to carefully push the lower part of the water heater casing towards you with both hands. Then lift up, remove completely and set aside. Now you can visually assess the contamination of the device and determine the scale of cleaning work.
How to remove and clean the igniter?
Evidence of contamination of the ignition tube: the igniter flame spontaneously extinguishes; a weak tongue of flame rises up without moving towards the burner due to insufficient gas pressure (if the pressure of the main or bottled gas has weakened, then the igniter has nothing to do with it).
Cleaning the igniter will stabilize the ignition, prevent popping noises and the formation of soot on the heat exchanger grates.
Please note: before you start cleaning a clogged igniter of a Bosch geyser, be sure to double-check that the gas tap of the device is closed!
Tools needed: flat-head (minus) screwdriver or thin pliers with curved “lips” (platypus). The ignition tube should be removed carefully, without pushing through the heat exchanger jacket.
The procedure for dismantling the water heater igniter:
- Top end. You need to pull up the bracket that holds the flared edge of the pilot tube at the end of the burner. Unclench the bracket slightly, then move it upward with duckbill pliers or pry it with a screwdriver until it is completely removed;
- Bottom end. It is necessary to press out the edges of the bracket securing the igniter;
- Removing the igniter. Having freed the ends of the tube, all that remains is to lift it up and remove it in a “pull” motion.
To clean the cavity of the ignition tube, you will need a piece of not too stiff wire, on which a piece of lint-free cloth (for example, a microfiber cloth) is clamped. We stretch a homemade “brush” inside the tube, then lightly tap it and blow through it.
The igniter tube is made of aluminum and can be easily dented. Therefore, cleaning, and especially tapping, must be done carefully, without excessive stress.
It is also necessary to clean the tungsten spring located on the underside of the tube. This will ensure quick ignition from the piezoelectric element. Finally, it is necessary to clean the nozzle at the lower connection point of the ignition tube and the electrode located in front of the upper outlet of the tube from carbon deposits. They should be wiped with microfiber or other lint-free cloth.
Installation of a cleaned igniter into the column is carried out in the reverse order of dismantling. If cleaning is done effectively, the flame from the lit pilot tube will be almost invisible.
Cleaning the heat exchanger of a Bosch geyser
If, after removing the water heater casing and inspecting the heat exchange unit, soot contamination is found, it will require dismantling and complete washing. A smoked heat exchanger should be cleaned by removing it from the gas water heater.
After cleaning, the heat exchanger will not look new. The task here is to eliminate the maximum amount of contamination from the inner plane of the shell and, especially, from the radiator grille
The first step is to close the shut-off valves of the water and gas supply to the heating column. If you intend to completely remove the device and dismantle the heat exchanger, placing the column on the table (this will be more convenient) - disconnect the supply gas hose, water supply inlet and outlet, then remove the device from the mounts.
However, there is no need to remove the entire water heater; you can remove the radiator of the heat exchange module at the installation site of the device. Let's consider this maintenance option in detail.
Removing the water heater heat exchanger
The necessary tools are flat-head (minus), Phillips (plus) screwdrivers and duckbill pliers.
The water supply and drainage pipes from the heat exchanger are secured with brackets, which can be easily removed using a flat-head screwdriver and thin-lipped duckbill pliers
Attention: despite its externally large size, the heat exchanger is hollow inside and lightweight. When dismantling, handle it carefully, otherwise you will damage the shell!
The procedure for removing the heat exchanger using the Bosch WR13-2B as an example:
- Shut off the cold water shut-off valve in the supply to the water heater;
- Removing the column casing. Remove the adjustment knobs by pulling them towards you, unscrew the two screws on the sides at the bottom of the housing, pull the lower part of the casing towards you, lift it and remove it from the upper hooks;
- Pulling out the bracket securing the tube to the water distribution unit. Pry the bracket with a screwdriver, remove it using the duckbills, and move the tube to the right. Before removing the retaining bracket, place a wide container to drain about a liter of water from the heat exchanger;
- Removing the sensor terminals from the heat exchange tank and housing. Located on the left side of the device, wires go to them;
- Pulling out the bracket that fixes the water supply tube at the inlet to the heat exchanger (located on the right under it). The principle is the same - pry it out with a screwdriver, carefully pull it out with duckbill pliers, then remove the tube completely;
- Removing the protective screen in front of the ignition group by unscrewing two screws with a Phillips screwdriver. Then you need to remove the ignition group from the socket and remove it;
- Pulling the bracket from the hose at the outlet of the heat exchange radiator (using a screwdriver and duckbills), disconnecting the hose. Don't forget to drain the water first by opening the faucet on the sink;
- Unscrewing the two screws securing the sides of the main burner;
- Unscrewing the two screws securing the gas manifold under the burner (located under it, in the center);
- Removing the guide bar holding the heat exchanger at the top. There are two side screws for a Phillips screwdriver. Unscrew and remove the bar.
All that remains is to remove the heat exchanger along with the burner. Place the palms of your hands under the burner on its sides and firmly, not without extra effort, press the shell of the heat exchange radiator with your thumbs. Lift them up, then pull the top part of the heat exchanger towards you and remove both modules out.
Cleaning the heat exchanger and main burner
To clean and rinse the heat exchange radiator, you need to place it in a bathtub or other container of suitable size. To avoid scratching the bottom and walls of the bathtub bowl, you should first lay a cloth in it.
Using regular detergents, hot water and a long-bristled brush, remove any grime from the inside and outside of the unit. Before installing it back into the column, it needs to be dried.
When reassembling, keep in mind that the slight slope of the side fins should be oriented towards the center of the main burner
If the burner is dirty with soot, it must be disassembled and cleaned. The fastenings of the burner sections (Venturi tubes) are bolted, they are easy to unscrew.
Professional cleaning of a dusty burner is carried out with compressed air, and at home - with a soft brush and a vacuum cleaner. In case of serious contamination, you can wash with soapy water and wipe with a lint-free cloth, then dry and reassemble the burner.
Descaling process
To eliminate deposits of magnesium and calcium salts (scale) in the heat exchange radiator pipe, you will need to remove it and prepare it for washing with an acid-containing solution. Please note that soot removal must be carried out before descaling.
It is not beneficial to aimlessly spill prepared cleaning liquid based on citric acid. Be sure to use a funnel to fill the heat exchange tube completely
Do not try to peel off or dislodge the scale inside the copper tube of the heat exchanger! Firstly, this is an almost useless activity, because... the bulk of mineral deposits deep in the pipe will be inaccessible for cleaning. Secondly, scratching the thin walls of the tube will weaken its strength and cause deformation.
The following means will help remove scale from the column:
- Anti-scale preparations sold in hardware stores. The procedure for preparing each product for flushing work is indicated in the manufacturer's instructions;
- Lemon acid. Since the volume of the tube in the heat exchanger design is about a liter (the exact volume is indicated in the instructions for the device), you will need to prepare a hot solution in the proportion of 100 g of citric acid per 0.5 liter of water in a volume of 700-800 ml;
- Nine percent vinegar. Vinegar diluted in three parts of warm water can remove scale from the heat exchange radiator of the column. The required volume of solution is 700-800 ml.
No other means like Coca-Cola or homemade solutions based on active acids (hydrochloric, nitric, sulfuric, etc.) can be used to remove scale - soda will have no effect, and acidic solutions can damage the tube.
It is necessary to turn the heat exchanger over with the radiator plates down and the tube inlet and outlet up, insert a funnel into the tube and pour in the prepared cleaning solution. Chemical descaling will take several hours, so it is more convenient to fill the heat exchange radiator with the solution from evening until morning.
If a column that has been regularly used for several years has not been descaled before, then the solution cleaner needs to be changed two or three times until completely cleaned. Otherwise, although the scale layer will be reduced, it will not be completely eliminated.
After waiting the period necessary for the destruction of scale deposits (more than 4 hours), you need to pour out the cleaning agent and rinse the tube with a large volume of clean water. During the flushing process, it is important to remove all fragments of sludge that have separated from the pipe walls.
The following article will introduce you to the reasons for water overheating by a water heater and how to eliminate the problem. All independent home craftsmen should read it.
Main characteristics of gas boilers AOGV-11.6-3
Floor-standing gas boilers AOGV-11.6-3 are single-circuit units with a rated power of 11.6 kW.
The device is capable of operating on both natural and liquefied gas with very economical consumption. Today this is the best option for heating a house with an area of up to 110 square meters. m. At the same time, the unit has acceptable dimensions (850x310x412 mm), which makes it easy to find a place in the house and facilitates the installation of the boiler. In general, AOGV-11.6-3 are reliable and practical; these heating devices are time-tested and ideal for use in Russia. AOGV boilers do not require any special conditions for operation. However, after several years of operation, it may be necessary to clean the unit with all its components from soot and other contaminants.
How quickly soot will accumulate in your AOGV depends on several reasons, including the initial correct installation of the device. The process of cleaning AOGV is not so complicated, so it is advisable to carry it out regularly, at least as a preventative measure before the start of each heating season.
When starting the gas boiler cleaning procedure, pay more attention to the details of any design in the unit. Everything has its purpose, and ill-considered actions can lead to emergency situations.
