If your furnace isn’t working, use this checklist before reaching for the phone to call your HVAC contractor. You might be able to get it working again, saving yourself some time and avoiding a service call.
Check the thermostat first. Make sure that it’s on the heat setting. Try turning it up five degrees warmer than its current setting. It should kick on in a few seconds. If that doesn’t work, remove the cover and use a soft brush to remove the dust from it. If you have a programmable thermostat, find your owner’s manual and change the setting to manual at the temperature you want.- Remove the cover from the blower and see if it’s been accidentally turned off. If it’s on, go to your circuit-breaker box and reset the breaker for the furnace.
- Inspect the air filter. A dirty filter impedes airflow through the blower, and if the heat exchanger gets too hot, the furnace will shut off prematurely. In fact, checking your filter monthly and replacing it when it’s dirty lowers your heating bills and increases the life of your system.
- Make sure that the gas is on. Find the valve that shuts the gas off to your home and see if someone inadvertently turned it to the off setting.
- See if the flue is plugged. Sometimes birds enter it seeking warmth. It may also be plugged with dead leaves. Turn off the furnace before cleaning it out.
- If you have a high-efficiency system and the furnace isn’t working, the drainpipe may be plugged with mold or landscaping debris. Remove the drainpipe and flush it with a mixture of 25 percent bleach and 75 percent water. Rinse it with clear water.
- Check all the registers to see that each is getting airflow. If not, you could have ductwork problems.
- Check the furnace vents outdoors and clear away any blockage.
If you need help with any of these steps when your furnace isn’t working, contact Marsh Heating & Air Conditioning. We’ve provided quality HVAC services for the Twin Cities area since 1974.
Our goal is to help educate our customers in Minneapolis-St. Paul, Minnesota about energy and home comfort issues (specific to HVAC systems). For more information about furnaces and other HVAC topics, download our free Home Comfort Resource guide.
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