During the harshest winter months, when temperatures drop below freezing, there is nothing worse than waking up freezing cold to realize “My furnace stopped working!” Sadly, it usually happens when you need warmth the most and the temperature has already dropped.
With the proper maintenance, new model furnaces are designed for reliability over a long period, so a sudden breakdown can be just as surprising to you as it is inconvenient. The reasons behind a furnace not working can be very simple, with little elbow grease to get it back up and running, or complicated enough to call in a qualified HVAC furnace technician.
If your furnace stopped working, there are a few steps you can take before phoning a furnace technician for repair. However, complicated problems involving wiring, thermocouples, blower motors, gas valves, and heat exchanger are better off addressed by a furnace expert.
Below are 6 basic DIY tips and tricks to try when your furnace stops working:
1. Ensure the filters are clean and free from debris.
A dirty or clogged air filter can cause a furnace to shut down. Debris and dust restrict the airflow, making the heat exchanger overheat and automatically shut off for safety. Dirty filters can also cause soot buildup, which prevents your furnace from working efficiently.
To check if you need to replace the filter, hold it up to the light and look for any dust particles. If you cannot see the light clearly through them, it’s time to replace them. You can use pleated filters for three months, but if you live in a dusty home or you have a pet, it’s better to change them every month. Filters with a higher MERV rating should be changed at least once every two months.
2. Check the furnace switch and circuit breaker.
It’s possible that your furnace is not receiving the power it needs to run properly. Check if the furnace switch isn’t in the ‘off’ position and reset any tripped circuit breaker on your electrical box. All furnaces, including gas system models, use electricity to operate the furnace fan motor, furnace control board, and blower.
3. Check furnace thermostat settings.
The thermostat is the furnace’s control center and helps to regulate the furnace temperature. Some problems associated with thermostats include:
- incorrect settings
- improperly wired furnace
- damaged or weak batteries
- loose connections
- dead display screen
To troubleshoot the thermostat, simply switch it off and on. This helps to reset the furnace system timer and restore its functioning. Ensure that the thermostat is set to “heat” mode and the temperature is set higher than the current room temperature (Preferably five degrees higher). Replace the batteries if it’s a digital model, and tighten any loose connections.
4. Inspect air ducts for any blockages.
Air ducts are used to transfer heated air from the blower to the rest of your home. If there’s any leakage or blockage in the ducts, you may have uneven heating in your rooms. To inspect:
- Check any ductwork visible in the furnace and attic or crawlspace.
- Look for branching points or gaps in which air can escape. Use duct sealant or metal duct tape to seal the gaps if you find any.
- Ensure the dumpers are fully open to allow air to flow through.
5. Check the furnace pilot light, if necessary.
A dirty or faulty ignitor/sensor can prevent it from lighting. If your furnace is of an older model or has a standing pilot light, you may need to check the furnace burner and pilot light for problems. Most furnace manuals will provide detailed instructions on how to light the furnace up again.
6. Ensure the gas supply is on.
Similar to switches, the gas supply can be accidentally shut off. If you have a natural gas furnace, make sure the furnace’s pilot light is lit, and the main gas valve is turned on. Trace the gas line to the supply meter outside your home or building and make sure it’s in the ‘on’ position.
If all else fails and you cannot figure out why your furnace isn’t working, or you don’t feel comfortable attempting these fixes yourself, City Energy is here to help. We offer furnace repair, maintenance, and installation services to ensure your furnace is up and running again in no time.