How to clean a gas water heater

To ensure regular hot water supply for their house or apartment, many owners install a gas boiler in the kitchen . The device is compact, does not take up much space on the wall, and even a teenager can figure out how it works.

Such water heating equipment will serve its owner “faithfully” for more than a dozen years, but only under the condition of correct operation and periodic cleaning. How to rinse and clean the gas water heater with your own hands at home (for example, the Zanussi GWH 10 Fonte Glass Rialto model )? For more information, see the article.

See also: The main causes of a gas water heater malfunction: 6 breakdowns that can be repaired by hand

Why are the “insides” of the gas column clogged?

The reason for such contamination lies in the principle of operation of the device. The device heats water with gas, and therefore accumulations of soot and carbon deposits cannot be avoided. In addition, the incendiary element itself is very often contaminated, collecting soot on its wick.

But the real apocalypse comes when scale “settles” in the pipes of the water heater. It not only interferes with the normal operation of the equipment, but can completely disable it, completely clogging the plumbing part. The formation of scale in the heat exchanger is especially dangerous.

The heat exchanger is a collection of tubes placed above the gas burner. Water should flow through them constantly and unhindered, it is in them that it evenly heats up. When scale builds up in these pipes, hot water supply interruptions occur.

You may be interested in: 9 important questions when choosing a gas water heater

It’s time to cleanse: the first signs

You can determine that a gas water heater (for example, from Bosch ) needs cleaning by 4 characteristic signs:

  1. The device stopped turning on or often goes out during operation. When there is 100% certainty that gas is supplied to the column without interruption, and water is supplied with a stable pressure, the reason for such independent shutdowns may be an excessive amount of burning on the incendiary element. The problem can be eliminated only by cleaning the burner.
  2. The thermal protection of the device is activated. To prevent the column from overheating, the equipment has a thermal sensor. It signals an increase in temperature, warning the owner of a malfunction. If this sensor is often triggered, it is worth cleaning the pipes from scale. Since limescale has good thermal insulation, it interferes with the normal cooling of the appliance.
  3. For no apparent reason, the productivity of the device has decreased. If the water begins to heat up more slowly or the pressure level has dropped significantly, you need to check the heat exchanger for scale and clean out the accumulated products of the column’s activity.

So, it is clear with the contamination of the device, but how to clean the gas water heater from scale and soot when such a need arose? The answers are in the following sections of the article.

Means for cleaning the gas column

The rules for caring for the gas water heater are described in detail in the instructions for the device and it can be dangerous to deviate from these requirements. If the water heater suddenly becomes clogged, use only the agents recommended by the manufacturer to clean it. They should also be indicated in the relevant paragraphs of the operating manual. And it is better to entrust the cleaning process to professionals. In this case, not only will the blockage be removed, but the warranty will also be preserved.

Important ! Unauthorized reading with unauthorized means is hazardous to health! If during the process of descaling or burning one of the elements of the column is damaged and a gas leak appears, call 104 immediately.

Only if the user understands all the possible consequences and accepts responsibility, you can clean the device yourself. How and how to flush the gas water heater (for example, the Ariston brand ) from scale in this case? You can also use ready-made preparations or alternative methods. Which is better and more effective: “vigorous” chemistry or “grandmother’s” cleaning, the comparative table will show:

Solves the problem Folk remedy Chemical drug
Scale inside the heat exchanger A mixture of 0.5 liters of hot water and 100 g of citric acid. Calgon or Anti-scale (erodes the layers of scale inside the pipes).
A dense layer of carbon deposits (can only be removed from the heat exchanger, the gas part is cleaned by specialists) Dilute table vinegar and warm water in a 1: 3 ratio. You can use 7-10% hydrochloric acid or other strong chemicals. Important! Work requires accuracy: the product should never get on the skin or mucous membranes.

See also: TOP-5 of the best manufacturers of gas water heaters

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The instructions for gas water heaters clearly state that unauthorized cleaning can lead to breakdown or, worse, gas leakage. These operating rules must be followed. Even if maintaining the warranty is not so important, safety is a priority. It is worth remembering that in any case, you can only descale the heat exchanger and wash off the soot from the burner surface in the device on your own.

To help the owners of gas water heaters, a manual of three points is offered, which together will help solve the main problems with interruptions in the water heater .

Descaling: work procedure

To carry out such a manipulation, you can use both folk remedies and chemical solutions. Having cast your vote in favor of chemistry, you must follow the instructions exactly. If you choose citric acid or vinegar, then the work consists of the following stages:

  • the gas water heater turns off;
  • the heat exchanger is disconnected from the rest of the elements by hand and removed from the wall, water is drained from it;
  • at the same time connect a hose to the pipe that supplies water to the column to avoid leaks;
  • with a pear, syringe or watering can, the resulting solution is poured into the pipes of the heat exchanger;
  • now the heat exchanger body is lowered into a deep basin with the same mixture and left in this state for several hours or overnight.

After that, the part must be rinsed well under running water, connected back to the column (as an option, the column of the Ariston FAST R ONM model ) and then start the device. Pressurized water will remove all scale, leaving the pipes perfectly clean.

Nuance : It is easy to check the effectiveness of your work – just look at the color of the water: if it is transparent, then all the scale has come out.

Anyone who dreams of a new device will be interested in reading: Replacing an old gas water heater with a new one: 5 important points 

Can the heat exchanger be cleaned without dismantling?

Immediately the answer is: “Yes, you can.” To do this, it is necessary to remove the front protective panel and disconnect the heat exchanger from the pipe that supplies water to the gas column. A drain hose is connected in its place.

When these preparatory procedures are completed, any chemical agent (or folk composition, if desired) is taken and poured into the pipes of the heat exchanger through the inlet. It is worth filling the “insides” slowly, in a thin stream, in order to avoid a harsh reaction and pushing the product back.

In this form, the device is left for 2-3 hours. After the expiration of the time, you need to reconnect the hose and drain the waste water with scale and other impurities. Then turn on the column and check its operation.

Removal of soot and grime

Cleaning the gas water heater (for example, the Bosch Therm 4000 O WR model ) from combustion products, as well as from scale, should be entrusted to professionals, especially when the device is under warranty. You can only remove soot from the surface of parts on your own without disassembling the gas part. How to do it? The process takes 10-15 minutes and consists of the following stages:

  • the gas supply is turned off and the upper case is removed;
  • all internal elements are gently wiped with a rag or cleaned with a vacuum cleaner;
  • the cover is installed back and the functionality of the device is checked.

If the gas wick starts to burn weakly, it means that the nozzle is clogged. It is located on the gas manifold, next to the pressure sensor. You can clean the nozzle with an ordinary thin wire and a stiff brush. Upon completion of work, be sure to check the element for gas leaks. To do this, lubricate the burner with soapy water (bubbles appear in the event of a leak).

Better prevention than cleaning

Prevention is necessary to prevent scale, which is the main scourge of gas water heaters (for example, such as Zanussi columns ). It appears not only as a result of salt deposits from hard water, but also as a result of the constant high temperature in the appliance. To keep the pipes clogged with this “filth” as little as possible, it is necessary to set the optimal temperature regime.

Another way to prevent limescale is to install water filters or electric softeners. They keep harmful salts out, allowing the heat exchanger tubes to last longer. However, the cleanliness of the filter and the electric softener must also be monitored.

You may be interested in: TOP-10 gas water heaters of 2017


Knowing how to clean the heat exchanger of a gas column and periodically following the recommendations outlined in the article, it will be possible to significantly extend its service life. And this, in turn, guarantees a constant supply of hot water for the needs of the whole family and savings on expensive repairs in the service center.

by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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