Furnace Won’t Start: What Do I Do?

By the time you realize your furnace has stopped working, it’s already too late. Your home is likely getting colder by the minute as you watch the temperature drop on your thermostat. But even if you don’t have your furnace’s manual on hand, there are a few basic troubleshooting techniques you can try before you call for help.

Basic Troubleshooting

Check The Thermostat

The first place you’ll likely head when your furnace doesn’t kick on is the thermostat. If other people live in your house, someone could easily have turned the unit off. Make sure it isn’t set to cool and that the temperature inside your home doesn’t exceed the temperature selected on the screen. If all of that checks out, try upping the temperature by five degrees or more to force the heat to kick on.

Check The Breakers

Another basic item you can check is your breaker box. Your furnace is controlled by a circuit breaker that is hopefully labeled. Even if this breaker is in the off position, you may find that your blower motor is on a separate circuit breaker, so check that, as well. Turn any applicable breakers to the “on” position and wait to see if your furnace kicks in. If it comes on, then knocks the breaker off again, you may find that you have a wiring problem that needs to be addressed by a professional.

Intermediate Troubleshooting

Change Your Filters

If you haven’t changed your furnace’s filter lately, the solution could be as simple as a quick trip to the local hardware store. Clogged filters are among the most common causes of furnace malfunctions, leading to wasted money on service calls. Try to keep your filter changes on a set schedule to avoid unexpected problems.

Make Sure The Gas Is On

For a gas furnace, you may find that either the pilot light has gone out or the gas valve may be shut off. Look at the unit itself and determine if the pilot light is lit. If so, feel the side of the furnace. If it’s cool to the touch, you likely have a problem with the thermostat, furnace control board, or the gas valve.

Advanced Troubleshooting

Flush The Drain Line

Those who feel comfortable doing more advanced work on their furnace may consider flushing out the drain lines to repair the problem. Condensation can cause mold or mildew to collect inside those lines, leading to clogs. A cup of bleach can help wash away those clogs to bring the HVAC unit back to full operation.

Check The Exhaust Flue

Your furnace’s flue could be the cause of the shutdown, especially if you have an older unit. Flues can corrode over time, which can not only cause your furnace to stop working, but it could send dangerous gases into your home. If you suspect the flu might be the cause, you can replace it yourself, but you may find it well worth the investment to bring an expert in to do the repairs.

Once you’ve gone as far in the troubleshooting phase as possible, the next step is to call in a professional HVAC Contractor to inspect and repair your system. Many furnace malfunctions can be repaired in a matter of minutes, so you likely will find the charge is minimal.

Do you have questions about your furnace? Our team of Furnace Repair experts is ready to help. Contact us today to schedule an appointment.

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