Up to $3,000 in rebates available now! See here for full details: Read More

Skip navigation

Start Your Career Today! Learn How


Kilowatt Heating, Air Conditioning and Electrical Blog

Why Your Furnace Keeps Shutting Down


This was the first weekend in Southern California of true cold seasonal weather. That may not seem cold to other parts of the country, but it’s cold for us! This means you probably turned on your furnace this weekend for the first time in … well, it’s been a bit, hasn’t it?

We hope you had a smooth switch over to using the furnace. But you are reading this post, after all, and that means the furnace is already giving you problems by shutting down early and not getting the house warm.

Before we go further and look at the reasons you may need to have furnace repair in Van Nuys, CA from our technicians, a quick reminder about heating maintenance: if you haven’t scheduled it, that might be the reason you’ve got a furnace acting questionably. Never miss out on having this job done during the fall, since you’ll be able to head off problems like the ones we’re going to look at below.

Some Reasons for Your Furnace Shutting Down

There are several causes for a furnace shutting down only a short time after coming on and failing to run long enough to deliver sufficient heat to a household:

  • Clogged air filter: If we had to wager on the trouble with your furnace, we would pick this. The filter on your HVAC system is there for both the AC and furnace, and if you haven’t changed it since the end of summer, the filter is likely heavily clogged. If this is the case, the filter can cause the furnace to overheat rapidly and trip its limit switch, shutting it down. If the blower for the furnace is causing a circuit breaker to trip, this could also be a clogged filter issue. Put in a clean filter and remember to change it every one to three months to avoid future problems.
  • Miscalibrated thermostat: If you haven’t been using the thermostat for a recent stretch, you might not be aware that it has malfunctioned and isn’t reading temperatures accurately. If the thermostat is recording temperatures in the house that are higher than they really are, it will send a signal to the furnace to shut down early. Thankfully, this is an easy problem for our technicians to fix: we’ll recalibrate the thermostat to record accurate temperatures. 
  • Other thermostat malfunction: There are other possible troubles with a thermostat that can lead to it shutting down the system early. Please don’t try to “override” this problem with higher and higher settings; that may lead to damage to the HVAC system.
  • Dirty burners: The burners in your gas furnace may be covered with dust, dirt, grime, rust flakes, etc., and this may cause problems for them staying lit. Because of the flame sensor in the furnace, if the burners go out, the furnace will shut down. You can’t clean the burners yourself; leave the job to professionals who can do it safely. 
  • Broken control board: The control board is the electronic component that manages the furnace’s functions. If it’s malfunctioning, it can cause the furnace to continue to shut down prematurely.

Kilowatt Heating, Air Conditioning and Electrical serves Los Angeles and the San Fernando Valley. Call our certified service technicians 24/7 for exceptional customer service!

Comments are closed.