Your blower is likely throwing cold air because of an incorrectly set thermostat, a clogged air filter, or an ignition/flame sensor malfunction causing a safety shutdown.
Your fan might blow cold air when the heat is on because the thermostat is set to "ON" instead of "AUTO," the air filter is clogged, or the heating element has malfunctioned.
If your HVAC system isn't blowing warm air, start by checking the thermostat settings and batteries; more complex issues like faulty wiring or ignition system problems may necessitate professional assistance. Airflow restriction due to clogged air filters can result in your system blowing cold air.
If your heater is blowing cold air, check your thermostat to ensure it is set to "Heat" and the fan is set to "Auto" rather than "On". Then, inspect the air filter for clogs, check the furnace power switch, and ensure the furnace door is securely closed.
Reset the Furnace
Turn the thermostat to "OFF." Locate the power switch on the furnace (often looks like a light switch) or the circuit breaker. Turn it off for 30 seconds, then flip it back on. Turn the thermostat back to "HEAT."
To reset a furnace blower motor, turn off power to the furnace using the emergency switch or the circuit breaker. Wait 2-3 minutes, then locate the red or yellow reset button typically found on the blower motor housing. Press it firmly, and restore power.
If your furnace is blowing cold air, the most common causes are a dirty air filter, incorrect thermostat settings (fan set to "ON"), or a pilot light that has gone out.
Yes, you should turn the furnace off if it is continuously blowing cold air. Turning it off prevents the system from blowing unheated air, stops it from wasting electricity, and prevents further damage to the unit if there is a malfunction.
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
If your furnace is running but only blowing cold air, the system is usually in a safety lockout mode or experiencing an ignition failure. This often means the fan motor is running to cool the system down or circulate air, but the heating element or burners are not firing.
A bad or clogged heater core is usually indicated by little to no heat from the vents, a sweet, syrupy smell inside the cabin, foggy windows, or damp, sticky carpets.
On average, replacing a heater blower motor or fan costs around £190, with most jobs falling between £110 and £300.
Check These 3 Easy Fixes First
Sleeping with a fan on isn't inherently dangerous, but it can cause irritating side effects like dry eyes, sore throats, congestion, and muscle stiffness. The constant breeze pulls moisture from your skin and nasal passages while continuously circulating household dust and pollen around your room.
Your heater or furnace is blowing cold air
What fails first on a furnace? The most common early failures are the furnace ignitor or flame sensor, as they experience regular wear and tear and are critical to starting the heating cycle.
On average, a furnace blower motor lasts between 10 and 20 years. However, this lifespan can be significantly shortened by a lack of maintenance, specifically if air filters are not changed regularly, causing the motor to overheat and overwork.
Homeowners insurance may cover the cost to repair or replace your furnace or boiler if it's damaged or destroyed by a covered peril. Covered perils as defined by your policy typically include events such as: Lightning. Fire.
5 Warning Signs It's Time for Furnace Replacement
Heating Schedules. Keep to a steady heating schedule over winter to keep a home consistently cozy. HVAC technician Josh shares, 'On average, in winter weather, most furnaces or boilers will cycle on and off for eight to 12 hours per day. That's assuming daytime temps around 35-45°F (1 to 7°C) and nights in the 20s.
If your furnace is blowing cold air, start by checking that your thermostat is set to "HEAT" and the fan switch is set to "AUTO" rather than "ON". Next, ensure your air filter isn't heavily clogged and your air vents are fully open, as restricted airflow frequently triggers safety shutdowns.
How to Stay Warm if Your Furnace Breaks
A frozen pipes furnace failure can cause major problems inside your home. Ice builds up fast in unheated spaces, and when frozen water expands, it can burst pipes wide open. That kind of mess is the last thing anyone wants during a winter heating outage.
In general, you can expect your furnace to cycle (on-off) about 3 to 8 times per hour in cold weather. Several factors determine how often the furnace cycles on in winter. The key factor is the outdoor temperature and the heat loss rate of your home.