Boiler Not Working — What to Do

Check the Basics First

Before assuming the worst: check the thermostat is set above the current room temperature, check the programmer/timer settings haven't changed, check the condensate pipe hasn't frozen (common in winter), check the boiler pressure gauge (should be 1–1.5 bar), and check whether the pilot light has gone out (older boilers only).

Low Boiler Pressure — Fix It Yourself

If the boiler pressure gauge reads below 1 bar, the system needs repressurising. Most boilers have a filling loop — a flexible hose connecting the boiler to the mains water supply. Open the valve slowly until pressure reaches 1.5 bar, then close firmly. Reset the boiler.

Frozen Condensate Pipe

Modern condensate boilers have a white plastic pipe running outside. In cold weather this can freeze, triggering a fault code. Thaw it by pouring warm (not boiling) water along the pipe. Once thawed, reset the boiler by pressing the reset button.

Boiler Fault Codes

Modern boilers display fault codes when something goes wrong. Common codes: F1 (low pressure), F22 (no water detected), E1 (ignition failure). Look up your specific boiler model's fault code guide online or in the manual. Many faults can be resolved by repressurising or resetting.

When to Call a Gas Safe Engineer

You must call a Gas Safe registered engineer for: gas leaks (leave the property immediately if you smell gas), boiler replacement, any internal boiler fault beyond repressurising and resetting, no hot water or heating after all basic checks, and any work on gas pipework.

Annual Boiler Service

A boiler should be serviced every year by a Gas Safe engineer to maintain efficiency, safety, and warranty validity. Annual service cost: £60–£120. This prevents most emergency breakdowns and extends boiler life.