Boiler Will Not Ignite? What to Know
A boiler that will not ignite cannot produce heat or hot water. Ignition failure can have several causes that require professional diagnosis.
Urgency: High urgency
Possible Causes
- Faulty ignition electrode
- Gas valve not opening
- No gas supply to the boiler
- Flame sensing electrode problem
- Blocked condensate pipe (safety lockout)
- Failed printed circuit board
- Safety thermostat tripped
Safe Homeowner Checks
These observations do not require touching the equipment.
- Check if other gas appliances in your home are working (to confirm gas supply)
- Look for an error code on the boiler display
- Listen for whether the boiler attempts to ignite (clicking sounds)
Next Steps
- Do not repeatedly reset the boiler if it is locking out
- Check whether the condensate pipe is frozen (in very cold weather)
- Record any error code displayed and provide it to the technician
Safety Reminder
If you smell gas, suspect carbon monoxide or believe there is an immediate danger, leave the property and contact emergency services or the appropriate gas emergency authority. Do not remain inside — exit the building immediately and call for help from outside.