The expansion tank of the heating system regulates the pressure in the system and is therefore crucial for efficient heating performance and function. Regular maintenance of the expansion tank can prevent problems.
Expansion vessel - task
The pressure equalization tank consists of a chamber for water, a chamber for gas and a membrane located between them. When the water in the heating system is heated, its volume increases. This causes more water to enter the expansion tank chamber and the membrane compresses the section that contains gas.
If the water cools and is thereby reduced in volume, the pressure of the gas causes itself to be the membrane moves in the other direction, flushing the water back into the heating system will. This balances out the pressure differences and enables efficient heating.
Common mistake
If the heating stays cold or only warms up unevenly, it is often just water
refilled. This also applies if water drips from the safety valve. The problem here is that water is always refilled, but the level can be too high. This causes water to be lost again and again.In addition, the actual cause can be misunderstood. A leaky valve, a tear in the membrane, too little gas or pressure are possible triggers. These, in turn, cannot be remedied by the water level alone. When performing a check, you should therefore pay attention to various factors.
pressure
The correct pressure in all areas is important for the functioning of the heating system. Therefore, the pressure should be checked urgently during an inspection. If this is too high or too low, regulation must take place.
How high the pressure should be depends on the respective system and the amount of heating water. Apps, programs or the computers of the providers of expansion vessels can be used as orientation.
Valve and diaphragm
That
Safety valve is used to prevent overpressure. If the pressure rises too high or is set too high, water escapes over it and has to be topped up again and again. The valve can be checked by:The pin is pushed in slightly
If water and not just gas escapes, a crack in the membrane is very likely In this case, the pressure equalization tank has to be replaced because the membrane cannot be used alone switch.
Is checked with a cloth or bucket
By wiping it with a cloth, you can easily determine whether the valve is tight enough. If the cloth is damp, either the pressure is too high, there is too much water in the system or the membrane is torn.
Pressure is applied
A light pressure test on the pin of the valve can be used to determine whether it can be moved without any problems or whether it stalls.
water
If the filling level of the heating system keeps dropping and water has to be topped up very frequently, there can be various reasons for this. Including damage to the valve and membrane.
In any case, it is crucial to check the water level during maintenance. This means that this point is an essential part of the checklist.
gas
The second chamber in the expansion tank is filled with gas. In theory it can
they are filled with ordinary air using an air pump. However, it is better to use nitrogen. This does not cause any corrosion and is therefore gentle on the entire system, even if the membrane breaks and the gas gets into the heating system.During a check, care should be taken to ensure that there is sufficient but not too high pressure. If necessary, the chamber must be refilled with gas.
Beat
The simplest variant of the control is to knock off the compensation vessel. It should sound completely hollow in the area of the gas. In the area of the water chamber, the sound should become duller when knocking. By tapping it, you can quickly and easily determine whether the membrane is still intact or whether it has cracked and thus mixed water and gas.
Ideally, this check should be carried out at the time of purchase in order to get a feel for the right sound. The instructions from the installer can also be helpful in order to determine whether there are any problems with just this simple test.
frequency
Many people only make the mistake of carrying out an inspection when difficulties such as uneven or insufficient heating, leaking water or noises arise.
It is better to carry out preventive checks at intervals of one to two weeks in order to identify damage and possible problems at an early stage and to be able to remedy them. This saves time and effort.
