Airdrie HVAC
Furnace Not Heating
A homeowner checklist for a furnace that will not produce heat.
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Immediate safe checks
Thermostat set to heat and above room temperature. Filter not packed. Power and switch at the furnace on. High-efficiency intake and exhaust clear of snow.
If you smell fuel or a carbon monoxide alarm has sounded, stop resetting the furnace and treat it as urgent.
What the sequence is telling you
A furnace that tries to start, fails, and locks out is giving you a status-light pattern. Write it down once. Repeated restarts wear igniters and leave the house colder.
A blower that runs with no burner flame is a different first question than a cabinet that stays silent.
Common fault categories
Airflow and dirty filters, ignition parts, pressure-switch or venting issues after snow, and control boards that no longer complete a cycle.
Do not assume the most expensive part from a forum post.
Ready to request this work?
When to stop troubleshooting
Do not bypass limit switches, work on gas valves, or defeat interlocks. Space heaters are only a short indoor-rated bridge.
What to include on the repair request
No-heat status, light pattern, age if known, and whether anyone in the house cannot easily leave. Use furnace repair or urgent no-heat help.
What different start patterns suggest
Silent cabinet: power, switch or a thermostat that is not calling. Inducer start then stop: venting or pressure switch, often after snow. Ignition attempts then lockout: ignition parts. Blower only: heat never started.
Those patterns are clues, not diagnoses. They belong on the request so the visit starts with the right tests.
Stop after one recorded lockout pattern. More resets are not more information.
Questions
- The fan runs but there is no heat. What is that?
- The blower is moving air without a completed burner cycle. That can be a thermostat fan setting or a heat-side failure. See also furnace blowing cold air.
Request heating or cooling help
Call for HVAC help or submit the quote form.