Repressure you central heating system
Now check your boiler pressure. Bleeding the radiators can cause the pressure to drop. It should read between 1 and 1.5 bar – check your boiler manual to be sure. Top your system up with water, if necessary.
Pressure is increased by adding water from your cold water main. The boiler will be connected to the main. You have to find what is called the filling loop in the system. It’s usually close to the boiler or even part of the boiler. If in doubt, check your boiler instructions or contact your installer.
Open the valve or valves on the filling loop – usually small handles – but if there isn't a handle you may need to use a screwdriver. Allow water to fill the system, while keeping a close eye on the pressure gauge, and turn off the valves as soon as the required pressure is achieved. Be careful not to over-pressurise the system.
Check the pressure regularly and top up when needed.