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Family-Owned & Operated since 1979


Emergency Services Available

Family-Owned & Operated since 1979



Cozy Heating Inc. Blog

Help! My Furnace Won’t Start Up or Stay On


We’ve experienced some intense winter weather already this year. With recent snowstorms and freezing-cold temperatures, it’s a good reminder of how essential your furnace is to keeping you not only comfortable in your home, but safe as well.

Unfortunately, it’s when temperatures are at their coldest that a furnace can suffer a catastrophic breakdown, leaving you without heat. Let’s go over what could cause a furnace to not start up and not stay on. If you find yourself without heat during a cold spell, be sure to call us for prompt heating repairs in Bothell, WA, as soon as you realize there’s a problem. We’ll restore your heating as quickly as possible.

Furnace Capacitors

Your furnace requires many components to work properly. Two important ones are the electronic capacitors, the start capacitor and the run capacitor. They are tasked with the important job of controlling the blower fans. 

If either one of these capacitors fails, then your furnace could not possibly start or run. But the capacitors are not the only cause of furnace malfunction. Let’s go over what else could be going on.

Troubleshooting Furnace Startup Issues

There are several reasons your furnace may not turn on including:

  • A miscalibrated or faulty thermostat. Even the tiniest malfunction with a thermostat could result in a misreading of the temperature in your house which will prevent the unit from signaling your furnace to turn on. Frayed wiring could also impact the thermostat and disrupt the signal it’s trying to send to your heating system.
  • An old electronic igniter. If your furnace is gas-powered, it still requires electricity to run. The system uses an electronic igniter which activates the burners. The igniter typically needs replacement every few years and can burn out before a routine maintenance appointment.
  • A dirty or rusted-out burner. In a furnace, the burner is where the gas jets ignite to provide heat. However, if the burner has a buildup of dirt or grime due to a lack of maintenance, or if rust flakes get inside of it, it will experience problems drawing in enough oxygen to light the furnace.

The Furnace Starts, But Doesn’t Stay On

Again, this could be a thermostat issue. If the thermostat thinks it has reached the desired temperature, it will shut the furnace off. Other reasons this might happen include:

  • A blown-out pilot light. The pilot light is the continuously burning flame that’s used to light the burner and start a furnace. If it goes out for any reason after it’s started up, then it’s not going to cycle back on later.
  • A faulty gas valve. This component controls how much gas flows into a furnace. If there’s a problem with it, then the furnace won’t like it because it won’t have fuel to burn. If your pilot light is still lit but the furnace won’t stay on, then this could be the reason.

Contact Cozy Heating Inc. to schedule heating repairs in Bothell, WA. We Won’t Quit Until You’re Cozy.

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