Flushing the gas boiler heat exchanger with citric acid

For comfort and financial efficiency, it is essential that our homes have effective insulation and heating systems. The gas boiler is one of the many parts of a heating system that is essential to producing heat in the winter. But over time, mineral deposits and debris can build up on the heat exchanger of the boiler, reducing its efficiency. Flushing the heat exchanger with citric acid is one way to solve this problem, and it has many advantages.

Fruits like oranges and lemons frequently contain citric acid, which is well-known for its organic cleaning abilities. It aids in dissolving buildup that can obstruct heat transfer, such as scale and rust, when used to flush the heat exchanger of a gas boiler. This easy-to-use yet powerful technique can raise the heating system’s efficiency to a considerable degree, guaranteeing improved performance and possibly reducing energy costs.

Hard water is one of the main causes of the accumulation in the heat exchanger of a gas boiler. High concentrations of minerals found in hard water, such as calcium and magnesium, have a tendency to precipitate out and deposit as scale over time. Because these deposits act as insulators, the boiler must work harder to reach the desired temperature and the heat exchanger’s efficiency is decreased.

A cheap fix for this frequent issue is to flush the heat exchanger with citric acid. When used as instructed, citric acid is safe for the environment and the boiler, unlike certain commercial descaling products. It is also reasonably priced when compared to specialized cleaning agents and easily found in most grocery stores.

Maintaining a gas boiler’s lifespan and maximizing its performance requires routine maintenance, which includes flushing the heat exchanger with citric acid. You can make sure that your heating system runs effectively and keeps your house warm and comfortable all year long by adding this easy-to-do yet efficient cleaning method to your regular maintenance schedule.

Step	Description
Mix Citric Acid Solution	Prepare a solution of citric acid by mixing it with water according to the manufacturer"s instructions.
Turn Off Boiler	Turn off the gas supply to the boiler and allow it to cool down completely.
Drain Water	Locate the drain valve on the boiler and attach a hose. Open the valve to drain any remaining water from the boiler.
Apply Citric Acid Solution	Pour the prepared citric acid solution into the heat exchanger through the filling loop or another access point.
Let it Sit	Allow the citric acid solution to sit in the heat exchanger for the recommended time, usually around 30 minutes to an hour.
Flush the System	After the allotted time, flush the heat exchanger thoroughly with clean water to remove any loosened deposits and citric acid residue.
Reassemble and Restart	Reassemble any parts that were removed, close the drain valve, and restart the boiler. Check for any leaks and ensure proper functioning.

It’s important to keep your house warm and energy-efficient, and flushing the heat exchanger in your gas boiler with citric acid is one efficient way to do that. The accumulation of scale and mineral deposits in the heat exchanger over time can lower its efficiency and possibly cause damage. By removing these deposits with a citric acid flush, heat transfer is restored to its ideal level and overall performance is enhanced. By performing this easy maintenance, you can increase the longevity of your boiler, reduce your energy costs, and make sure your house stays toasty warm throughout the winter. In addition, it’s an affordable solution that you can quickly complete on your own using simple supplies and tools.

How to clean and what to wash the heat exchanger of a two-circuit gas boiler

The heating boiler requires routine maintenance, just like almost any other piece of technology used in challenging environments. Cleaning the heat exchanger in a gas boiler is one of the most crucial tasks carried out during maintenance.

Why it"s needed

The term "heat exchanger" refers to a metal (or cast iron) box that has an integrated radiator that receives heat from the burner’s flame on the outside and transfers it to the fluid inside. The heat exchanger operates at peak efficiency when it is clean, providing nearly all of the energy received for heating. But over time, different impurities—which are mixtures of dissolved salts in the coolant—start to precipitate on the walls of the internal channels (scale). If hard water is used in the DHW mains, there is particularly intense limescale deposit formation in the secondary heat exchanger of a two-circuit boiler.

Such heat exchanger channel contamination can have a number of unpleasant effects, including:

• Reduction in the efficiency of the boiler. Mineral deposits have a much lower thermal conductivity than metal, so to heat water will have to spend much more energy. Accordingly, gas consumption will also increase.
• Heat exchanger overheating. The scheme of operation of gas boilers assumes that the coolant coming from the return mains cools the internal cavities of the heating element. In case of scale formation, the cooling efficiency decreases, the heat exchanger overheats and quickly fails.
• Breakdown of heating equipment. Mineral deposits on the inner walls of heat exchangers make it difficult for the coolant to pass through them. This creates additional load on the circulation pump, which will quickly exhaust its resource if the narrowed channels are not cleaned in time.

As a result, regular flushing of the heat exchanger will ensure the least amount of fuel required and help to save a significant amount of money by preventing the failure of costly components.

Frequency of heat exchanger cleaning

There may be some conflicting information regarding how frequently different heating boiler components should be cleaned in different sources. Maintenance schedules are typically listed in the instructions specific to a given model. It is important to remember that these data are approximations and are intended to be used under ideal circumstances. In actuality, heat exchanger flushing might be necessary more frequently.

When the gas boiler is operating, there are a few indirect indicators that can help you determine how much the heat exchanger is clogged:

• Gas consumption has noticeably increased. Practice shows that the increase in fuel consumption due to deposits inside the heating element can reach 15%;

This is the heat exchanger’s appearance following prolonged use.

Modern boilers are built to last a long time, and replacement parts can get expensive. Thus, as soon as the above-mentioned symptoms appear, the heat exchanger needs to be cleaned. In any other case, heating boiler maintenance costs could rise sharply.

Methods of cleaning heat exchangers

Different methods can be used to flush the heat exchanger. We will examine these in more detail later on, and in the meantime, we’ll cover how to clean a two-circuit boiler’s heat exchanger, which is especially prone to the buildup of organic deposits.

Manual cleaning

In order to gain free access to the heat exchanger and solve the problem in this manner, it must be fully removed from the boiler. After that, it can be cleaned using a variety of tools:

• Mechanical cleaning. It is possible to remove the scale from the inner surface with the help of a hard metal brush or a special scraper;
• Flushingin special formulations. Most often, heat exchanger parts are soaked in an acid washing solution. This method is particularly effective for removing heavy soiling, e.g. in the ducts of two-circuit gas boilers.

The manual cleaning technique is easy to use and efficient. You can use it on your own to flush the heat exchanger. The only warning is that all joints must be airtight and caution must be used when working with the boilers’ sealing components.

Hydrodynamic cleaning

Heat exchangers in gas boilers can be flushed without needing to be disassembled.

The process of hydrodynamic cleaning involves employing high-pressure water jets to mechanically remove scale from pipeline walls, sometimes accompanied by small abrasive particle impurities.

Specialized units that pressurize the mains to 1,500 bar are used in this procedure. It is the most efficient heat exchanger cleaning technique, albeit a bit pricey.

Chemical cleaning

The process of chemically cleaning gas boiler components involves introducing an acidic flushing solution into the system with the aid of a specialized tool known as a booster. After that, the heat exchanger is cleaned by running this solution through it for a few hours. Trivalent iron and carbonate scale deposits are the most challenging to remove, but you can do it with this method.

Before and after cleaning of the heat exchanger

The high expense of the reagent, metal deterioration, and a significant volume of hazardous waste are the drawbacks of chemical cleaning.

Liquids for flushing heat exchangers

Finally, let’s talk about the issue of how to clean the gas boiler’s heat exchanger. Even though there are a lot of suggestions in different places, care should be taken when selecting a cleaning solution.

Hydrochloric acid is highly recommended by many experts for flushing. Although it is an extremely effective descaling agent, the compound’s aggressive nature may harm the protective coating on the heat exchanger’s interior surface.

Furthermore, there is proof that metal brittleness can result from hydrochloric acid flushing.

Citric acid poses less of a risk to the heat exchanger’s material. It works flawlessly with every type of deposit and unique reagents, such as DETEX, Cillit, Sanax, and others.

The heating system’s service life will be extended and maintenance expenses will go down with timely and appropriate maintenance of its components. The heat exchanger will have the biggest impact on this procedure because it is one of the most crucial tasks completed during boiler maintenance.

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Natalia, depending on the design of the boiler, you need to do the following operations:
1. Using a long screwdriver, remove the front cover of the unit, the protective cover and the combustion chamber deflectors.
2. Disconnect the interfering wires of flow sensors, temperature sensors, etc. д. as well as the pressure pipes (so that you do not forget how they are connected, you can take a picture of the internal filling of the unit).
3. Remove the fan and exhaust gas deflector.
4. The plate heat exchanger itself is similar to the radiator of a car heater and is fixed on the latches.
5. When removing the appliance, avoid sudden movements and mechanical impact – it is very easy to damage the heat exchanger.
6. When disconnecting copper tubes from the radiator, be sure to hold the nuts located at the base of the device with a second wrench, otherwise you can damage the outlet pipes of the device.
After cleaning the heat exchanger, it is installed in reverse order.

December 11, 2015

Here are some situations where cleaning is necessary: 1. The device’s computed values are considerably different from the passport’s values; the heat exchanger uses more heat energy but performs less efficiently. 2. Regular replacement of the rubber seals on the heat exchanger is due. 3. A build-up of dirt and scale so dense on the heat exchanger plates that it can only be extracted mechanically.

December 11, 2015

My personal experience tells me that, before selecting a heat exchanger cleaning technique, one should consider all of its technical attributes, evaluate the level of fouling, and consider the effort required to choose the option that will allow the heat exchanger to be restored to its original condition in the most gentle way possible without causing damage to the plates or seals with chemical reagents.

For further details on the subject, visit http://all-for-teplo.ru.

How to wash the heat exchanger of a gas boiler

A heat exchanger is a device that transfers heat from one heat transfer medium (water) to another (air). It consists of heat transfer elements and cavities for the passage of water. If the water is hard, over time, scale will form in the heat exchanger and must be removed periodically. Therefore, if on the surface of the heat exchanger appeared scale, rust or other contaminants, it is necessary to know how to wash the heat exchanger of the gas boiler. This should be done regularly for reliable, safe and uninterrupted operation. Regularity of flushing depends on the quality of water (especially its hardness) and the parameters of boiler operation (temperature, load). With any method of flushing, first remove deposits using solutions of various acids or special reagents, then flush with water.

The initial method for cleaning a gas boiler’s heat exchanger involves removing it.

• screwdriver;
• enameled basin;
• citric acid.

Procedure:

1. Close the gas supply taps on the heating system.
2. Drain the water.
3. Remove the heat exchanger by carefully loosening the screws and water pipes. Also remove the overheating sensor from the heat exchanger housing.
4. Prepare citric acid solution (20 g per 1 liter of water).
5. Place the heat exchanger in a basin. Pour in the prepared solution. The heat exchanger must be completely immersed in the solution.
6. Heat the solution, wait 5-10 minutes.
7. Drain the solution.
8. Thoroughly rinse the heat exchanger with running water.
9. Put the heat exchanger in place, fastening all screws and tubes, fixing the overheating sensor.

The second method (using specialized flushing units) for cleaning the gas boiler’s heat exchanger

• Chemical flushing unit (consists of a solution tank, pump and connecting hoses);
• special reagents or citric acid.

Procedure:

• Shut down the boiler.
• Drain the water.
• Dismantle the circulation pump to avoid possible damage.
• In its place, install a unit for flushing, connect it with special hoses.
• Prepare the solution in the tank of the flushing unit. Refer to the instructions for use for the recommended concentrations for each reagent.
• Turn on the pump.
• When circulating the solution, it is necessary to monitor the pressure in the installation, not allowing it to be exceeded.
• Drain solution.
• Flush with water.
• Dismantle flushing unit, put circulating pump back in place.

By being able to flush the gas boiler’s heat exchanger, you can extend the life of the appliance and the heating system overall.

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How to clean a gas boiler with heat exchanger flushing

In accordance with an ancient custom, the user cleans the gas boiler on a regular basis and flushes the heat exchangers when absolutely necessary, such as when the water isn’t heated at all or something breaks. For your money, a master responds to your call, fixes the unit, cleans, and arranges everything. The majority of gas boilers used in homes and apartments are made in a way that makes it possible for you to clean them yourself on a regular basis.

When to clean

There are three possible ways that events could unfold:

1. Preventive cleaning of the boiler is done by the homeowner himself 1 time in 2 years with the least cost.
2. The procedure is performed as the heat exchangers are contaminated with soot and scale, which reduces the efficiency of heating and water heating for DHW needs. In this case, it is still possible to clean the boiler yourself, although calling a master is also not excluded.
3. The heat generator has stopped due to a malfunction, which often happens during the heating season. The malfunction is eliminated by a specialist, who also cleans the heat exchanger of soot.

For homeowners, the final two scenarios are obviously undesirable because they entail expense and inconvenience. When using a condensing boiler for heating that has a burner and heat exchanger of a unique design, make sure you have a master. It is not advised to attempt repairs on your own unless you have extensive experience with this type of heating apparatus.

In conclusion, the best course of action is to perform preventive cleaning and flushing of the heat exchanger of a two-circuit gas boiler. This can be done quickly and at no cost.

How to clean the heat exchanger of a floor standing gas boiler

No specialized tools are needed to disassemble the heating unit at home; a standard set of screwdrivers, wrenches, and pliers will do. When the house is not heated, in the off-season, the heat exchanger is cleaned preventively to remove soot and scale. After turning off the gas supply, begin disassembling the boiler by removing the burner device in the following order:

1. Disconnect all wires from the gas valve.
2. Remove the thermocouple from the combustion chamber, connected to the gas valve by a capillary tube.
3. Disconnect the gas supply pipe.
4. Unscrew 4 nuts (or bolts) holding the stove with burner. Pull the assembly outward, as shown in the photo:

An old toothbrush can be used to clean the gas boiler’s burner without the need for additional disassembly. Soot should also be removed from the igniter, piezoelectric ignition device, and flame control sensor, if applicable. To access the heat exchanger, you must now take off the boiler’s top cover and disconnect the chimney pipe and draught sensor. You can see the insulation covering the chimney casing in the opened aperture. After carefully removing the insulation, remove the cover by unscrewing the screws holding it in place. There is a heat exchanger underneath, and to remove the steel turbulators, follow the instructions in the picture:

Removing the turbulators from a partially soot-clogged heat exchanger

It makes no sense to elaborate on the cleaning process for turbulators; it simply involves using a metal pile and an ordinary brush. However, using clever instruments that they made by hand based on the size of the smoke tubes is the best way to clean the floor boiler’s heat exchanger. If their cross-section is rectangular, you will need to fashion small scrapers in the shape of scoops and a handy flat spatula out of thin metal slats.

The same tools are made slightly curved for round flame pipes. A spatula should be used to remove any leftover soot from the corners of the pipes after using a scoop to clean the walls.

After everything is done, a brush attached to a long handle can be used to sweep the heat exchanger’s entire surface. After cleaning the flue pipes, the soot must be removed from the bottom where it accumulated. This is the appearance of a clean heating unit heat exchanger:

In order to thoroughly examine how to clean a gas boiler at home, watch the following video:

Note: The master’s video presented an orderly violation of actions. He cleans the heat exchanger first, then takes out the soot-covered burner. This is incorrect; the burner must be removed before cleaning the soot off the flame pipes’ walls.

Cleaning the wall-mounted heat generator from soot

For the majority of wall-mounted gas boilers, accessing the primary heat exchanger is fairly easy. The following is the work’s algorithm:

1. Disconnect the gas supply by closing the corresponding tap.
2. Remove the front panel of the unit.
3. Unscrew and remove the front cover covering the combustion chamber.

Covering the nozzles with a piece of thick paper or cardboard is necessary to prevent soot from getting into the gas burner’s holes and to avoid having to think about removing the burner to clean it. Afterwards, use an old toothbrush to remove any soot from the heat exchanger fins. Use a brush with a soft metal pile if the adhered layer does not yield.

After you’re done, use a brush to carefully remove the soot-covered sheet of paper from the interior of the unit. The video provides detailed instructions on how to service a wall-mounted boiler:

Scaling of the heat exchanger

There are two methods for cleaning the internal heat-exchange surfaces of gas boilers: one method involves removing the heat exchanger, and the other does not. Selecting option number two is advised if you plan to clean and flush your heat generator on a regular basis. Every time you need to remove the heat exchanger from the boiler, it can be a real pain to disassemble it. Indeed, and different heaters have different constructions; some require almost screw-based assembly.

You will need to build a flushing unit, or booster, with your hands in order to clean the boiler without disassembling it. It’s a 15-20 liter container with attached hoses that is filled with flushing solution. Their ends are attached to the heat generator’s supply and return pipes, which activate the heating function. The circulation system operates on a separate pump, just like the heating system. It would be even better if the household could locate a reversible pump that could periodically reverse the direction of the liquid’s flow.

Advice: Install a mesh filter on the hose that feeds the solution from the booster to the heating unit to stop limescale from spinning in a circle. It’s possible that multiple cleanings will be required during the flushing process.

Prior to cleaning the gas boiler’s primary heat exchanger, the following tasks must be completed:

• relieve pressure in the network to zero, using a special valve (such are in some boilers) or Maevsky valve on the nearest radiator;
• disconnect the heater from the system and empty it;
• Check if your model of unit has a built-in strainer, remove and clean it.

A few words about what you can wash the heat exchanger of the gas boiler. The most popular folk remedy, safe for all elements of the heat generator, is considered a solution of citric acid and vinegar. According to feedback from users of a well-known forum. 9% vinegar or citric acid dissolved at the rate of 20 g per 1 liter of water works well. If necessary, the concentration can be increased. In addition, there are a lot of factory-made means for chemical cleaning of heat exchangers (for example, Antinakipin). Flushing time is indicated on the product package, and when working with citric acid, the duration of the process depends on the degree of contamination and may take from 1 to 3 hours.

Advice: In the event that a reversible pump is not available, alternate the hoses periodically while the machine is operating to initiate the liquid flow in the opposite direction. The heating system needs to be turned off in the event of reverse flow.

After the unit has finished rinsing, fill the tank with regular, purified water, rinse it again to remove any remaining dirt or chemistry, and then clean the strainer.

How to flush the heat exchanger of a two-circuit boiler

The type of heat exchanger that is installed in your heat generator will determine how to descal from the DHW path. Only two of them exist:

• bithermal, it combines heating of the heat carrier and DHW water;
• stainless steel secondary heater.

Because it can be challenging to remove the first kind of unit, cleaning is best done with a booster. The circulation pump and the boiler itself are started after the hoses coming from the tank are connected in place of the cold and hot water outlets. 50–55 degrees should be the upper limit of the heating temperature.

In most circumstances, a secondary heat exchanger installed in a double-circuit boiler can be removed. In order to accomplish this, take off the front panel, unscrew the control box, and set it aside. The bottom-mounted secondary heat exchanger is fastened with two bolts. Following removal, it is cooked on a gas stove by submerging it in a pot of water that has been dissolved in citric acid, as shown in the following video:

Citric acid flushing of the gas boiler heat exchanger is a practical way to keep your heating system long-lasting and efficient. Citric acid helps restore optimal heat transfer within the heat exchanger by dissolving mineral deposits and scale buildup, ensuring your boiler performs at its best.

Using citric acid instead of harsh chemical cleaners has several advantages, chief among them being safety and environmental friendliness. Since citric acid is a naturally occurring chemical that can be biodegraded, it is safe to consume in citrus fruits. As a result, you can clean your boiler without being concerned about damaging residues or their effects on the environment.

Furthermore, using citric acid to flush the heat exchanger is a reasonably easy and affordable maintenance task that can be completed without the help of a professional. Homeowners can maintain the optimal operation of their heating systems by performing routine maintenance with basic equipment and appropriate guidance.

The lifespan of your gas boiler can be greatly increased with routine maintenance, which includes flushing the heat exchanger with citric acid. You can lower your risk of expensive repairs and guarantee steady warmth and comfort in your house throughout the winter months by avoiding corrosion and blockages.

To sum up, adding citric acid flushing to your boiler maintenance schedule is a sensible and sustainable approach to maintain the dependability and efficiency of your heating system. You can reap the long-term advantages of a well-maintained boiler by devoting a small amount of time and energy to this straightforward maintenance task.

Video on the topic

Heat exchanger flushing. Gas heater. Citric acid

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Cleaning the gas boiler Vailant without disassembly citric acid

CHEMICAL WASHING OF PRIMARY HEAT EXCHANGER OF FERROLI GAS BOILER. Descaling.