If you are constantly losing pressure in the heating system you could try the following to establish the cause: Check all visible joints including radiator valves and connections for obvious signs of leakage. Ensure that there are no leaks to any under-floor pipe work. Check that there is no water being discharged from the pressure relief valve (sometimes referred to as an overflow). This pipe usually goes from the boiler through to an outside wall and terminates outside. Check this for signs of dripping. If it is wet, this may mean that the pressure relief valve is faulty. In either case, if your heating system keeps losing pressure do not hesitate to contact Opus property maintenance for advice and assistance.