Gas heating systems can be flushed
Gas heating systems can be flushed
Draining a fully pumped gas heating system makes it easier to work on the system. To work on a metal radiator problem or to extend the system maybe. This is often executed by the heating engineer during repair or extension work although some experienced homeowners have been known to clear their own gas central heating systems.
In most circumstances Flushing the central heating is executed to clean the radiators. Switching off the gas boiler and central heating pump should be the first actions you take. To successfully finish this undertaking you also need to guarantee that no more water enters the gas central heating system.
The gas central heating system has a expansion tank in the attic which will ensure that any water shortfall is filled up. This has a ballvalve that is the same as the one seen in your toilet cystern. As the water level rises the ball floats on the surface and shuts off the valve. The valve will be opened in the water levels fall as the ball will float on the falling water surface. To ensure that the heating system fully empties we need to stop this mechanism. To prevent any more water entering the valve needs to be off.
Having stopped the entry of any water to your gas central heating system you can now take the next step by linking a hose pipe to an outlet valve on a heating radiator and running this to the outdoors of your property. Once you vent the outlet valve the water will be able to flow through the hose to the outdoors empty. Obviously, if you want to empty the whole gas central heating system you will need to connect the hose to one of the level metal radiators. Check now that no water is moving into the gas heating system and that the heating radiators are fully emptied before you do any further work.
By opening the bleed valves in the metal radiators on the top story you will enable air to enter the gas heating system and speed up the Flushing process. When all the water has gone you can now commence work on the system.