Troubleshooting
Combi Boiler Producing No Heat
The boiler is on but your home stays cold — here's what's usually behind it.
A combi boiler that has power but produces no heat is one of the most common winter call-outs in Greater Vancouver. The cause can range from something simple like low system pressure or a thermostat setting to a failed pump or diverter valve.
Because the boiler is a gas appliance, the actual repair belongs to a licensed gas fitter — but understanding the likely cause helps you describe the problem and get the right fix faster.
Common causes of no heat
- Low system pressure (check the gauge — should read ~1–1.5 bar)
- Thermostat set too low, in 'hot water only' mode, or batteries dead
- Failed circulation pump or an airlock
- Seized 3-way diverter valve stuck on hot water
- Frozen condensate pipe in cold snaps
- Fault code locking the boiler out
Smell gas or suspect carbon monoxide? Leave now.
If you smell gas, hear hissing, or your CO alarm sounds, leave the building immediately and call your gas utility's emergency line from outside. Do not operate switches or relight the appliance. Once you are safe, call us for a licensed repair.
Call 778-909-5731Frequently Asked Questions
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