Unfortunately, furnaces rarely wait for an ideal time to break down. They typically conk out on you when they are being pushed to the limit, such as the middle of the night as the temperatures dip below freezing.

There are many furnace problems that cause your unit to stop working properly. In our most recent blog, the heating and cooling experts at Edwards Royal Comfort discuss one specific issue – why a furnace might fail to kick on and what you can do to troubleshoot this annoying issue. In some cases, repairs such as these are better left to a trained heating, cooling, and indoor air quality professional.

How Come My Furnace Won’t Kick On?

The reasons behind a furnace or heating system not kicking on vary from simple issues to significant system malfunctions. Here are some of the common reasons that stand in the way of your furnace starting up, and some simple troubleshooting you can do to correct them.

1. Check the Thermostat Settings

One of the simplest reasons a furnace won’t start up is because of incorrect thermostat settings. If it feels cold in your home and you think the furnace should have fired up already, the first thing to check should be the thermostat.

  • Make sure the thermostat has power. Replace batteries if needed and make sure the circuit breaker has not tripped if your thermostat is powered by the home’s electrical system.
  • Make sure the thermostat is set to HEAT mode.
  • Check the temperature settings. It’s possible someone may have lowered them, causing the furnace to not kick on.

2. Power Problems

If there’s no power to the furnace or heat pump, it won’t start up even when the thermostat tells it to. Inspect the unit’s power and fuel sources to verify your system has access to the juice it needs.

  • Check the electric panel to verify the furnace’s breaker has not tripped and reset it if necessary – do this for both electric and gas furnaces, as gas models do use some electricity to power certain components.
  • Furnaces have an ON/OFF switch that is typically located on the exterior of the unit or nearby on the wall. Make sure no one has bumped the switch into the OFF position – it should be set to ON.
  • For natural gas furnaces, check the gas valve on the supply line leading into the furnace – make sure the valve is open, which allows gas to flow to the unit. The valve handle should sit parallel to the gas pipe when it is open.
  • For propane or oil furnaces, check your fuel storage tank to verify you have enough fuel on hand to power the furnace. If fuel volume is too low, it may not properly exit the tank. You’ll need to schedule a refill.

3. Pilot Light Is Out

Some older gas furnaces still use a traditional pilot light to ignite the fuel and start the heating cycle. If this light goes out, the gas furnace won’t heat.

  • Remove the access panel to expose the ignition assembly.
  • Turn off the gas supply, and wait about 15 minutes to allow any gas to dissipate.
  • Follow the instructions in your owner’s manual to relight the pilot light.
  • If the pilot stays on once it’s relit and burns a strong, blue flame, you should be good to go. If it continues to extinguish, or if the flame is yellow and weak, call an HVAC technician to assess the system.

4. Dirty Furnace Filter

If your furnace has been running but suddenly stops and doesn’t kick back on, a dirty air filter could be to blame. A clogged filter can significantly restrict airflow, causing the system to overheat. When this occurs, the furnace may shut down to cool off.

  • Inspect the filter. If the surface is covered in particles and no light shines through, it needs to be replaced.
  • Insert a fresh replacement air filter of the same size into the filter compartment. Give the furnace time to cool down – it should start back up within the hour if a dirty filter was behind the issue.

When to Call Edwards Royal Comfort for Help

If these steps don’t get your furnace back on track, there may be a more complicated malfunction that requires professional attention. The heating and cooling pros at Edwards Royal Comfort perform reliable and accurate furnace and heating systems for homes throughout West Central Indiana. Contact us today to schedule a service call for furnace repair.