Furnace Installation

Common furnace problems, in order of likelihood

1. Dirty air filter: The most frequent and easiest issue to fix is a clogged filter. It restricts airflow, causing the furnace to overheat and shut down as a safety measure (short-cycling).

2. Thermostat problems: If your furnace won't turn on, the thermostat is a common culprit.

• Incorrect settings: It might be on the "off" or "cool" setting, or the temperature might be set too low.
• Dead batteries: For battery-powered thermostats, dead batteries can prevent it from sending a signal to the furnace.

3. Power supply issues: A furnace won't work if it's not getting power.

• Tripped circuit breaker: An electrical overload can trip the breaker, shutting down the furnace.
• Blown fuse: Similar to a circuit breaker, a blown fuse will cut the power.
• Power switch: The dedicated power switch for the furnace, often near the unit, may have been turned off by mistake.

4. Ignition or pilot light failure: This problem prevents the gas from igniting to produce heat.

• Older furnaces: The standing pilot light can get dirty or be blown out by a draft.
• Newer furnaces: The electronic ignitor can crack or wear out over time.

5. Dirty flame sensor: This safety device detects if the burner has ignited properly. A buildup of dirt and grime on the sensor can cause it to signal a malfunction and shut the furnace off, even if a flame is present.

6. Blocked flue or exhaust pipe: High-efficiency furnaces use PVC pipes to vent exhaust gases. A blockage from debris, ice, or snow can trigger a safety shutoff.

7. Condensate drain line blockage: High-efficiency furnaces produce water, which is drained through a PVC pipe. A clog can cause a backup of water, tripping a safety switch and shutting down the furnace.

8. Blower motor failure: The motor circulates air through your home. A failing blower motor can cause insufficient airflow, leading to overheating and system failure.

9. Failing high-limit switch: This safety switch is designed to turn off the furnace if it gets too hot. A malfunctioning switch can cause the furnace to short-cycle or shut down unexpectedly.

10. Cracked heat exchanger: This is a very serious and dangerous issue, as it can allow deadly carbon monoxide to leak into your home. Signs include a yellow or flickering pilot light and soot around the burners.