Troubleshooting Gas Furnace Problems

Posted February 3, 2015

What's worse than having no heat in the middle of winter? Only a little, if you ask us. There are a few problems homeowners commonly experience with their gas furnaces, and we're here to break them down for you. It's important to know what to look for when your furnace is not heating properly.

Wrong Thermostat Type

There are three basic types of thermostats: millivolt, line voltage, and low voltage. Low-voltage thermostats are the most commonly used thermostats in residential applications. They have to be matched to the system based on the type of furnace that is used, or you may run into problems. The best way to ensure you have a thermostat that matches your system is to get it from an HVAC professional or take your old one to the store with you and ask which type it is.

Squeaks, Rattles & Rumbles

Squeaks can be related to a motor failing or making noise. Air leaks can also cause squeaks. If you suspect this is the problem, check the joints where the sheet metal is connected. If you notice a small gap, you can cover it up with tape or a piece of putty. Rumbling and rattling can be a result of an out-of-balance blower wheel caused by debris or age. If you have an older furnace, it may use a belt to drive the wheel that blows the air into your house. If the belt is not lubricated properly, it can make noise.

Furnace Does Not Produce Heat

The purpose of a gas furnace is to produce heat to warm your home. If your furnace won't heat, there are a few possible causes:

  • An improperly adjusted thermostat
  • Lack of power or fuel
  • Pilot light that isn't lit

Make sure the set point on your thermostat is raised above the current temperature of the room, or else the furnace won't kick on. Next, make sure the power to the furnace is turned on. Check your breaker to make sure the lever is in the correct position. Most furnaces don't use pilot lights anymore, but if yours does, it may need to be relit. Follow the manufacturer's instructions and exercise extreme caution because dealing with gas can be dangerous.

Need Help with Furnace Troubleshooting in Chicago?

Knowing a little bit about your system, and being educated about it is the best way to stay on top of it and avoid breakdowns. In any instance where your system requires service or repairs or you're just not sure what the problem is, give ABC Plumbing, Sewer, Heating, Cooling and Electric a call at 888-868-6667 or contact us online for help.

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