No Heat from Your Boiler? What to Check
When your boiler stops producing heat, radiators stay cold and your home becomes uncomfortable. This symptom can have several causes, ranging from simple control issues to component failures.
Urgency: High urgency in cold weather
Possible Causes
- Thermostat not calling for heat or set correctly
- Circulator pump not running
- Air trapped in the system preventing water circulation
- Zone valve not opening
- Boiler in lockout mode from a safety trip
- No power to the boiler
Safe Homeowner Checks
These observations do not require touching the equipment.
- Verify your thermostat is set to heat mode and the temperature setting is above room temperature
- Check if the boiler has power (display is lit)
- Listen for unusual sounds from the boiler or pipes
- Check if other heating zones are working (if applicable)
Next Steps
- If the boiler display is off, check the electrical panel for a tripped breaker
- If the display shows an error code, record it for the technician
- If the boiler is firing but radiators are cold, you may have a circulation problem
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.