Some boilers stop heating properly when the pressure is too low. A small top-up can sometimes resolve this, but only if the boiler has an accessible filling loop and you are comfortable using it.
Never remove the boiler casing. If you smell gas, see water leaking from the boiler, or the pressure keeps dropping, stop and report the problem.
Read the gauge
Find the pressure gauge on the boiler display or front panel. On many boilers, the normal cold pressure is around 1 to 1.5 bar, but some models show a marked green zone instead.
If the pressure is very high, at zero, or the boiler is showing a fault code you do not recognise, do not try to force it back into use. Take a photo of the display and report it.
Top up pressure
If the boiler has a visible filling loop, open the valve or valves slowly and watch the gauge. The pressure should rise gradually. Close the valve firmly once it reaches the recommended range.
Do not leave the filling loop open, do not over-pressurise the boiler, and do not use tools or remove covers to reach hidden parts.
Watch for repeat drops
If pressure falls again, there may be a leak or a boiler fault. Check radiators, pipework and the boiler area for visible drips if safe to do so.
Report repeated pressure loss, no heating, no hot water, leak marks, unusual noises or error codes to 2let2, with the boiler make and any display code included.
