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Why Does My Gas Furnace Keep Shutting Down Early?

question-mark-badgeHas this been happening to you? You set your thermostat to turn on your gas furnace (or you have a program that turns it on at a specific time), and it turns on but shuts down only a few minutes later—long before your house has a chance to get warm. As you can guess, this isn’t normal. Your furnace is supposed to remain on long enough to reach the temperature setting on the thermostat and then gradually cycle off. Something is amiss, and you may need to call professionals in Haughton, LA for heating repair to get it fixed.

What’s causing the problem?

This is the tricky part: there are different possible causes for a gas furnace to shut down before it finishes warming up your home. They can range from minor issues you can correct on your own to serious repair issues that must have licensed HVAC technicians to solve. Below are a few of the most common causes of an early furnace shutdown:

  • Clogged air filter: We recommend you check the air filter first before doing anything else. If you haven’t changed it out regularly (we recommend every one to three months), it will be congested with dust and lint. The problem this creates is that lowers the amount of cooler air from the house that flows around the hot heat exchanger in the furnace. The heat exchanger won’t cool down, and the furnace will overheat. A safety mechanism, the limit switch, will activate to shut down the furnace. Keep a clean filter in the furnace and you shouldn’t experience this problem.
  • Malfunctioning thermostat: The issue may be in the thermostat. The thermostat senses when the temperature reaches its setting and then cycles off the furnace. But if the thermostat is picking up incorrect temperatures and detects the house is warmer than it is, it will turn the furnace off too soon.
  • Tripped circuit breakers: Check on the circuit breaker panel when the furnace shuts down abruptly. The blower fan may have put too much voltage demand on the circuit. (Yes, a gas furnace needs to have electrical power to run.) If you reset the breaker, but the problem persists, you’ll need a professional to take a look at it.
  • Oversized furnace: If this is the first season you’ve had your furnace, you may be dealing with a system that was incorrectly sized when it was put in. if the furnace sends out too much heat, it will raise the temperature so rapidly that the thermostat will shut the system down before it should. This is a common trouble if amateurs installed the furnace. The best way to solve the problem is to call on a professional contractor to have a correctly sized furnace installed.

Important warning: Aside from changing the filter, you should never tamper with a natural gas furnace on your own. This is potentially hazardous. In most areas, it is illegal for anyone except a licensed HVAC technician to work on a gas furnace. Stay safe and always let the pros handle the job.

Call the Doctor of Home Comfort: Hall’s Heating, Air Conditioning & Refrigeration.

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