Our tap water is rich in various chemical compounds. Passing through the coil of the gas column, it emits a precipitate covering the inner walls of the tubes. Over the years of operation, the scale layer is able to overlap the passage section by half. There is only one counteraction method - timely cleaning and washing of the heat exchanger. Consider several available methods, how to clean the gas column at home, choose the right one and service the water heater with your own hands.
Methods for cleaning an instantaneous water heater
Cleaning the gas column does not always mean complete disassembly, to the screw. But one question is the prevention of a fully operational unit, and another is the removal of long-term scale from a coil, soot from a burner. The instantaneous water heater can be serviced in the following ways:
- completely disassemble the column, clean the gas burner and flush the copper heat exchanger;
- flush the radiator without disassembling;
- clean soot and contaminants of the working elements of the unit - igniter, electrodes, water unit (in common parlance - “frog”).
Note. The “frog” through holes become clogged quite rarely. Usually they are cleaned when it is necessary to disassemble and repair the water unit, for example, to replace an unusable membrane. The device and the principle of operation of the elements of the water heater are described in detail on this page.
If the apparatus was operated without maintenance for many years, the channels were half full of limescale, and the flame of the gas burner turned yellow from blockages, then the first option is unambiguously implemented - complete disassembly. A similar decision is made when you need to solder a leaky radiator.
Preventive washing of the heat exchanger of a household column is carried out without dismantling (method No. 2). Local soot removal (option No. 3) is performed in case of ignition system malfunctions - the igniter barely burns, there is no spark on the electrodes, loud pops are heard in the combustion chamber at the moment of starting the burner.
How to flush a descaling column
What means do not use the owners of private houses and apartments when cleaning gas columns with their own hands - various acids, household chemicals and even electrolyte from batteries. We warn you: most of these compounds are unsuitable for servicing hot water devices, their use will not give a result, and can easily harm.
We will advise 2 remedies whose effectiveness has been tested by practice and confirmed by numerous user reviews:
- Inexpensive powder sold at grocery stores is food grade citric acid. 50–70 grams of the product is diluted in 1 liter of wash water.
- Special fluids intended for flushing from scale gas coil coils and plate heat exchangers of double-circuit boilers.
Note. In especially advanced cases, an increase in the concentration of citric acid to 100 grams / 1 liter is allowed.
Full Disassembly Service
Do not be afraid to disassemble the water heater, the procedure is not so complicated. The tool will require the most common - screwdrivers, pliers, standard wrenches. What you need to do before starting work:
- Close the taps for cold water, domestic hot water and gas pipelines. Disconnect the turbocharged column from the wall outlet.
- Substituting the container, unscrew the union nuts (American) on the connection of the water pipes. Disconnect the connections from the unit without losing the rubber gaskets.
- For convenience, it is recommended to remove the gas column from the wall. It is not easy to disassemble and clean the unit suspended too high or installed in a narrow niche.
- To dismantle the water heater, disconnect the gas line and the chimney pipe. Remove the unit from the hooks.
Lay the water heater on a horizontal surface and proceed to further work, whose order is described in our instructions.
How to remove the heat exchanger and column burner
We will show the disassembly sequence using the example of a cheap Chinese Novatek water heater. Introducing step by step instructions with photos:
- Remove the control handles mounted on the front panel. Turn out 2 self-tapping screws (or 2 plastic clips) and dismantle a casing of the device.
- The next step is to remove the smoke box. To do this, disconnect the wires from the traction sensor and unscrew the screws holding the diffuser box.
- Disconnect the heat exchanger tube from the water assembly by disassembling the union with the union nut. The second pipe must be freed from the lock washer, pressed with 2 screws.
- Disconnect the burner from the gas valve by unscrewing the 2 screws on the flange. Having moved the radiator up, carefully remove the burner device (moving towards you) and move it to the side.
- Unscrew all self-tapping screws connecting the heat exchanger with the back panel of the water heating system.
- Pull out the radiator completely and remove the burner by disconnecting the wires together with the ignition electrodes.
Note. When removing the heat exchanger, disconnect the wires from the temperature sensor.
Disassembly of gas columns from other manufacturers may differ, but not fundamentally. The order of work remains unchanged. We list some important points:
- in a smokeless turbine column you will have to dismantle the fan;
- in aggregates of Italian brands Ariston (Ariston) and some other pipes are connected not with nuts, but with self-clamping clamps;
- if the water heater is equipped with an igniter, then before removing the burner, disconnect the gas pipe connected to the wick.
Important! Do not lose rubber or other gaskets found during disassembly. Before assembling and installing the column, it is advisable to replace these seals with new ones.
The above process will be demonstrated in detail by our expert plumber in his video:
Flushing procedure
This operation is very simple compared to disassembling - cleaning the gas column begins with immersion of the heat exchanger in a container with washing liquid. The procedure is as follows:
- Take a bucket or deep basin, pour water and prepare a cleaning solution according to the recipe on the package. The concentration of citric acid is 50-70 grams per 1 liter of liquid.
- Immerse the heat exchanger in the tank with the radiator down and the pipes up.
- Using a watering can, fill the coil with detergent. Rinse it periodically with a new solution.
- Rinse the heat exchanger until a clean, flake-free liquid flows out of the tubes. Then pass the tap water through the coil to remove any residual product or impurities.
Tip. Using citric acid, heat the solution to a temperature of 50-60 ° C. The reaction will go more intensively and end faster.
The removed burner can be cleaned from the outside and purged or washed with a solution of citric acid (not more than 50 grams per liter of water). At the end, rinse the element with running water, blow it with compressed air and dry it thoroughly. Do not ignore other details of the geyser - a mesh filter, a smoke collector and a combustion chamber, remove soot and other contaminants from them.
After washing and drying, put the heat exchanger in place, connect the burner and follow the rest of the steps to reassemble the water heater. It is important to achieve a tight joint: when installing old gaskets, treat them with high-temperature sealant. Check the joints for leaks with water pressure (4-6 bar).
For reference. The duration of washing depends on the thickness of the scale layer inside the column heat exchanger and ranges from 2-3 hours (prevention) to 2 days.
How to remove scale without removing the radiator
To perform this procedure, it is enough to remove the front panel of the water heater and disconnect the heat exchanger tubes from the water unit. Do not ignore the second action and do not rinse the coil with the “frog”! You do not know how the detergent will act on the membrane and other parts of the water valve, so it’s better not to risk it so that you don’t later repair the unit.
There are 3 ways to flush the heat exchanger internally:
- Connect the hoses to the heat exchanger pipes and spill the cleaner manually through the funnel.
- Remove the gas column from the wall, turn it upside down and put on the floor. Periodically pour citric acid solution into the coil and flush scale with water through hoses.
- From a circulation pump for heating, make a booster - a device for pumping liquid through a heat exchanger. The scheme is simple: a pump, connecting hoses and an open container with detergent.
Recommendation. To protect the home-made booster circulation pump from contamination, install a mesh on the suction pipe to catch dissolved limescale.
The burner and the chamber of the geyser will have to be cleaned with a brush with a long soft pile. Use a home vacuum cleaner to remove dust.
We serve the igniter and the intake unit
If you need to clean the water unit, do not rush to disassemble the entire device. Look in the instruction manual for the water heater, find the “frog” in the diagram and proceed according to the following algorithm:
- Remove the knobs and front cover.
- Remove the water unit by disconnecting the nozzles.
- Remove the screws holding the cover, remove it and get to the membrane.
- Clean the filter mesh and water holes in the frog body using a wooden stick or soft copper wire. Remove the scum with a brush.
- Rinse the parts with water and assemble the assembly. Replace a damaged or cracked membrane immediately.
Clean the pilot burner (wick) nozzle with a thin copper wire or a toothpick moistened with alcohol. Wipe the ignition electrodes and the flask of the flame sensor (thermocouple) from soot, otherwise the column will turn off spontaneously over time.
When to clean the gas column
Information on the frequency of cleaning gas columns is rather contradictory. Some sources on the Internet recommend servicing annually, others - once every 6 months, and so on. The homeowner will be correctly guided by the quality of tap water and some signs indicating contamination of the apparatus:
- the heating efficiency and pressure in the DHW line decreased - the heat exchanger clogged;
- the ignitor burns with a yellow or red flame (should be blue);
- the color of the fire on the main burner also changed;
- the column does not light up and switches itself off at normal pressure in the network.
The average interval between preventive cleanings of the instantaneous water heater is 1 year. But you should consider the quality and hardness of local water. If it is saturated with salts, the scale will be deposited much sooner. In such cases, the use of softener filters is appropriate, otherwise all the water-heating equipment will quickly become worthless.