boilerintermediate

Why won't my boiler fire up or start?

Gas Safe Engineer
4 min read
Updated 11/28/2024
63 helpful

Quick Answer

Boilers fail to start due to thermostat issues, gas supply problems, ignition faults, or safety lockouts.

When your boiler won't start, it's frustrating - especially during cold West Midlands winters. Here's a systematic approach: **Check These First:** 1. **Thermostat Settings** - Ensure it's calling for heat and set above room temperature 2. **Gas Supply** - Check other gas appliances work (hob, oven) 3. **Electrical Supply** - Confirm boiler has power and no tripped switches 4. **Pressure Gauge** - Must be between 1-2 bar for most boilers **Common Boiler Faults:** - **Ignition Problems** - Spark electrode or gas valve issues - **Flame Sensor** - May be dirty or failed, preventing ignition - **PCB Faults** - Control board issues requiring professional repair - **Pump Problems** - Circulation pump may have seized **Modern Boiler Error Codes:** Different manufacturers show specific error codes: - Vaillant: F28 (ignition fault), F22 (low pressure) - Worcester Bosch: EA (ignition lockout), E9 (PCB fault) - Baxi: E133 (ignition fault), E125 (circulation fault) **Safety First:** Never attempt to repair gas components yourself. If you smell gas, turn off the supply and call the Gas Emergency Service (0800 111 999). Our Wolverhampton-based engineers carry most common parts and can often restore heating the same day.

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