How to drain a heating system
How to drain a heating system
Taking the water out of a fully pumped heating system makes many upkeep tasks easier. To work on a radiator problem or to extend the system maybe. Flushing your system is something that can be done by the none expert but capable do it yourself practitioner.
Whilst there can be a number of reasons the most popular is to flush the radiators. Before you do anything to the actual heating radiator you should turn off the boiler and any gas or electric that supplies the gas fired boiler. It is also important that you do not let any additional water into the gas heating system while you empty it.
The tank in the attic is used to normally top up the system with water. This has a ball valve that is the same as the one seen in your toilet cystern. As the water level rises the ball floats on the surface and closes off the valve. As the water level falls, say through Emptying, the ball drops in the tank venting the valve and allowing more water to enter the heating system. This is what needs to be contained when Emptying your radiator. A good way to do this is to prevent the ball moving by connecting it to the top of the cylinder.
Having stopped the entry of any water to your central heating system you can now take the next step by connecting a hose pipe to an outlet valve on a metal radiator and running this to the outside of your property. Once you open the outlet valve the water will be able to flow through the hose pipe to the outdoors empty. To drain your whole central heating system you need to attach this hosepipe to one of the ground floor radiators, the lowest ones in the house. Be patient and ensure that all water has emptied from the heating system and no more water is entering before you start any further work.
The process can be hurried up by venting the bleed valves in the top floor metal radiators. Work can begin when all the water has emptied out.