Start by checking the pressure gauge on your boiler about once a month. Your heating manual gives the right pressure for your system, and most sit between one and two bar. If the needle has dropped into the red, the system needs topping up.
Turn the boiler off first. Some filling loops are built into the boiler, so follow its manual for the exact steps. Open the filling valve slowly and you should hear water flowing in as the pressure rises. Watch the gauge the whole time so the system is not overfilled. At the right pressure, close both filling taps fully, as one left slightly open can push the pressure too high.
Bleeding radiators can make the pressure drop, so check the gauge afterwards. If it keeps falling, there may be a leak. Look around the radiator and boiler valves while the system is cold, because heat can seal small leaks for a while. A tiny leak can dry before you see it, leaving only a faint residue. Leave loose or broken pipe joints alone unless you are trained to repair them.
A boiler that keeps losing pressure has a fault in one of its parts. Have it inspected as soon as you can rather than carrying on topping it up. If you keep reaching for the filling loop, ring me at Discount Heating NW and I will come out and inspect it. Here is how I handle Boiler Repair across Liverpool.
