Wondering what’s causing your furnace to run constantly? Well, that depends on whether or not your furnace is heating your home to the set temperature. That said, there are two possible scenarios at play here:
1. Your furnace runs continuously but never heats your home to the set temperature. This problem is caused by these furnace issues:
- You’re setting your temperature too high and the furnace can’t keep up
- Your furnace is suffocating (usually due to a clogged filter)
- You have leaky air ducts
2. Your furnace heats your home to your set temperature and then continues to run non-stop. This means you most likely have a problem with your thermostat or thermostat wiring.
First, determine which of the above describes your problem. Then skip to that section below. We’ll explain what you need to do to fix the problem.
1. If your furnace runs constantly but never heats your home to your set temperature…
…there are 3 possible issues that could be causing this problem. Read on for an explanation of those problems and what you can do on your own to fix the problem before calling a pro.
Possible problem #1: You’re setting your temperature too high
Check your thermostat’s temperature. In Missouri, the average winter lows hover around the 20s so if your thermostat is set super high (say 85 or higher), your furnace may struggle to keep your home warm and run constantly to try and keep up.
What to do: First, try adjusting the thermostat to a temperature that’s lower than the current indoor temperature. If the furnace stops running after 3 to 4 minutes, it means your set temperature is too high. Adjust your thermostat anywhere from 68 to 72 degrees to avoid this problem in the future.
Possible problem #2: Your furnace is suffocating
Your furnace can only put out as much air as it “breathes” in. So, if it isn’t getting enough airflow, it can only put out a limited amount of hot air. And that means it will run constantly, trying unsuccessfully to heat your home.
What to do: Check and change your air filter if it looks like the filter to the left below. A clogged filter restricts the amount of air your furnace can breathe in.