Boiler troubleshooting — safe fixes you can try first.

Pressure gauge below 1 bar, or boiler locking out with a pressure fault.

1. Locate the filling loop under the boiler — usually a silver braided hose with two small taps.
2. Slowly open one tap, then the other. You'll hear water flowing.
3. Watch the pressure gauge — stop as soon as it reaches 1.0–1.5 bar (cold).
4. Close both taps firmly. Reset the boiler if it was locked out.

⚠ If you have to top up more than once a month, there's a leak somewhere — call an engineer.

Boiler seems to run but radiators/taps stay cold.

1. Check the thermostat is calling for heat (turn it well above room temperature).
2. Check the programmer is set to ON, not just timed.
3. Check the boiler display for an error code (see below).
4. Check the gas is on — try a hob ring; if that won't light, it's a gas supply issue.
5. Press the reset button on the boiler once — do NOT press it repeatedly.

Boiler stopped in cold weather, gurgling noise, error like F1, EA, F28 or FH.

1. Find the white plastic pipe running from the boiler to outside (often to a drain).
2. Pour warm — NOT boiling — water along the exposed section, especially at bends and the outlet.
3. Once thawed, reset the boiler. It should fire up normally.
4. Lag the pipe with foam insulation to stop it happening again.

One radiator stays cold while the rest are hot.

1. If it's cold at the top and hot at the bottom → bleed it (turn key anti-clockwise until water spits out, then close).
2. If it's cold at the bottom and hot at the top → sludge; needs a power flush.
3. If it's cold all over → check the TRV pin isn't stuck (unscrew the head and gently free the pin with pliers).
4. Re-check the pressure after bleeding and top up if needed.

No lights, no display, no response.

1. Check the fused spur switch next to the boiler is ON.
2. Check the household consumer unit — the boiler circuit may have tripped.
3. If it trips again immediately, stop and call an engineer — there's an electrical fault.