Why Does My Furnace Blower Run Constantly Without Stopping?
BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning provides expert advice on this common question for homeowners in Greater Vancouver. If you need professional service, our licensed technicians are available across the region.
When to Call a Professional for Help
While understanding the answer to this question is helpful, some situations require professional expertise. If you are uncertain about any step, if the problem recurs, or if you notice any signs of gas odour, carbon monoxide, or electrical hazards, contact BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning immediately. Our licensed technicians across Greater Vancouver can provide expert diagnosis and repair. We recommend professional service for any issue that involves gas, electrical components, or safety-critical systems.
Related Services from BC Wide
BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning provides comprehensive furnace service across Greater Vancouver, including diagnostic inspections, emergency repairs, scheduled maintenance, and system replacement. Our Red Seal certified technicians service all major brands and carry OEM parts in their vehicles. For emergency service related to this question, call (604) 330-3953.
Answer: Why Does My Furnace Blower Run Constantly Without Stopping?
If your furnace blower fan runs without stopping, the most common cause is the thermostat fan switch being set to ON instead of AUTO. Check your thermostat and switch the fan setting to AUTO — this allows the fan to run only when heating is needed. If the blower continues running after switching to AUTO, the fan limit switch may be stuck in the closed position, or the control board may have a fault. A stuck limit switch can cause the fan to run even when the furnace is off. Less commonly, a wiring short can keep the fan circuit energized. Professional diagnosis is recommended if the thermostat setting does not resolve the issue.
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.