Furnace won't start when you turn it on?

Adjusting heating unitYou can use the following as a cheat sheet to easily check your furnace before making a service call and having a professional come to help:


  • Are the batteries still working? If not, replace them.
  • Is it set to heat? Make sure it is and set it at least 5 degrees higher the room temperature.
  • Have a forced air furnace? Ensure that the thermostat switch controlling the furnace fan is “on.”

Fuel level

  • Have you run out? Don't laugh. It does happen. It's been a while since last winter and it's easy to forget how much fuel is left in the tank.

Circuit breaker

  • Your furnace circuit may have tripped to the “off” position since you last used it. Easily fixed. Just locate the furnace in your circuit breaker box and switch it back “on.”

Blown fuses

  • If the top of the fuse that handles the furnace has melted metal or a discolored glass window, replace it with a new one but don't forget to take any broken fuses with you when buying new ones to make sure you’re purchasing the correct fuse.

Emergency power switch

  • Does your furnace have an emergency power switch on the wall? It looks like a regular light switch, just make sure it's switched on. It may not come on immediately, so wait for a few minutes for the furnace to start running switch it on.

Dirty filters

  • Your furnace needs air to run and clogged filters can prevent your oil furnace getting enough. It will also make it run less efficiently or not at all! Check and clean those filters!


  • Make sure that that outdoor furnace vents are not blocked and that heating registers in your home are open.

It may be time to replace your furnace

  • If you've been having consistent problems with your furnace for a few years or if it's over 16 years old, it may be the right time to replace it with a new one. This will help you save on service and energy costs in the long term.

Preventive maintenance

  • Make sure to schedule your annual heating system tune-up or cleaning in the early fall, before you turn your system on for the first time.

Heating system and equipment repair services

For more information, or to schedule maintenance on your furnace, contact us today!