A gas furnace that won’t keep running long enough to warm up your house and keep it warm isn’t of much use to you. If you start running into the problem of a furnace shutting off early, either after several minutes or less than a minute, you’ll want to know why and what you can do to fix it.
In some cases, a gas furnace shutting off early is because of a simple problem you can correct yourself. In other situations, you’ll need professional furnace repair in Yakima, WA. Below we’ll look at some of the common reasons for this furnace malfunction.
Clogged air filter
This is one of the simple issues you can fix on your own. The air filter for your furnace needs to be changed for a clean one every 1 to 3 months or it will risk causing operational problems for the furnace. When a congested filter cuts off the flow of air into the furnace, it can cause the heat exchanger to overheat because not enough air is moving around it to cool it down. The limit switch will shut the furnace off because of the overheating. Put in a new filter to see if this fixes the issue, and set down reminders for yourself to replace the filter regularly in the future.
Faulty limit switch
We mentioned the limit switch above: it’s a key part of integrating the operation of the blower fan and the gas burners to provide a steady and even heat flow from the furnace. It also turns the furnace off in case the heat exchanger gets too hot. If the limit switch malfunctions, it may shut the furnace off too early. (On the other hand, it can also cause the blower fan to run nonstop.) You must have professionals repair or replace the limit switch.
Faulty flame sensor
This is another safety device that can end up doing its job too well! The flame sensor makes sure that the gas from the burners has ignited so unburned gas doesn’t flood the combustion chamber and create a hazard of flame roll-out or other dangers. If the flame sensor isn’t working, it will shut the gas flow to the burners off even if the burners have ignited. Like other components connected to the gas line of the furnace, only licensed professionals can safely fix the flame sensor.
When your furnace starts to shut down too early, you probably first checked to make sure the thermostat was set correctly. However, the thermostat may be inaccurately sensing temperatures in your house because of a miscalibration. When this occurs, the thermostat might think the house is warmer than it is and turn the furnace off too early. Please don’t push the thermostat setting higher to try to overcome this—it needs HVAC repair pros to either fix it or replace the thermostat unit.
Is your gas furnace more than 15 years old? If so, then problems with reaching your desired indoor temperatures often mean the furnace has worn down past its useful point. You can ask our technicians to examine the heating system to see if it can be repaired or if a replacement is the better option.