Is your furnace not firing up or producing enough heat this winter? Don’t panic – the cause is likely a common issue that you can often resolve yourself. In this post, we’ll explore the top 5 most frequent furnace problems homeowners encounter.
Understanding the typical failure points will help you properly diagnose issues. We’ll cover the symptoms, likely causes, and fixes for each one. Let’s get your furnace back to keeping your home nice and toasty!
#1 – Dirty Flame Sensor
The number one most common furnace problem is a dirty flame sensor. This simple failure accounts for the vast majority of no heat service calls.
Symptoms: The furnace igniter glows and main burners ignite for only 2-3 seconds, then shut off. This cycle repeats a few times before the furnace locks out.
Causes: The flame sensor gets covered in grime and corrosion over time. This prevents the sensor from confirming the burner flame is present, so the furnace shuts down as a safety precaution.
The Fix: Locate the flame sensor rod near the burner igniter. Scrub away debris using steel wool until the metal shines clean. This restores proper flame detection and keeps the furnace running.
#2 – Dirty Air Filter
Second on the list is a common maintenance oversight – clogged furnace air filters.
Symptoms: Furnace struggles to reach desired temperature and runs for extended times. Short cycling or overheating may occur.
Causes: As filters accumulate dust and debris they restrict airflow through the blower and evaporator. This strains the furnace blower motor and causes overheating issues.
The Fix: Check your furnace filter monthly and replace per manufacturer recommendations, more often for high dust conditions. Use proper filter types and sizes to avoid air restriction.
#3 – Bad Inducer Motor
Problems with the inducer blower motor that pulls exhaust gases out rank #3 for repairs:
Symptoms: Furnace doesn’t start at all, just hums. A pressure switch error code may show on the control board.
Causes: The inducer motor is seized up or obstructed from debris like dead birds or insect nests. This prevents combustion exhaust flow.
The Fix: Replace the inducer motor if not starting. Inspect the housing for any debris blocking the blower wheel – cleaning it out may get the motor going again.
#4 – Bad Blower Motor
Next on the list is blower motor failure:
Symptoms: A burning plastic or electrical smell coming the furnace. Overheating causes repeated temperature limit trips and furnace cycling on/off.
Causes: When blowers seize up, air can’t circulate across the heat exchanger to warm up the home. This leads to dangerous overheating.
The Fix: Test if the blower motor is very hot when running. If so, the motor windings have likely failed and requires replacement. Turn power off before touching.
#5 – Bad Control Board
Rounding out the top 5 is control board problems:
Symptoms: Can vary – no components starting up, only some working, reversed heating and cooling modes.
Causes: Internal control board failures disrupt electrical signals to furnace components. This prevents proper operation.
The Fix: Use a multimeter to check for 24V power during operation. If the board has power in but doesn’t supply voltage out to components, replace it.
Get Comfortable Again!
Armed with knowledge of the most common culprits behind furnace problems, you can carry out troubleshooting much more efficiently. Tackle repairs proactively to get your heat running reliably again before the deep cold of winter sets in.
What furnace troubleshooting tips or insights can you add to this list? Let us know in the comments below! And check the in-depth furnace repair video linked here for even more helpful diagnosis and repair guidance. Stay warm!
