Why does boiler pressure keep dropping?
Pressure that keeps falling is never random. Here are the main causes — and when it’s time to call an engineer.
If your boiler pressure drops every few days, water is escaping from the system somewhere.
The main causes:
- A hidden leak in a radiator or pipe joint
- The expansion vessel losing its air charge
- The pressure relief valve letting water out
You can top the pressure back up to 1.5 bar yourself, but if it keeps happening, have the cause found — otherwise the pump and the main control board may be damaged.