Understanding and Avoiding Furnace Short Cycling

April 19th, 2019 | seoteam
avoiding furnace short cycling

During the winter we’re finally nearing the end of, did you notice your furnace turning off and on more often than usual? If so, was this observation accompanied by unusual heating bills during those months, whether larger or smaller than you’d expected?

If so, it’s possible your furnace is short cycling. At Action Plumbing, Heating, Air & Electric, our furnace repair experts are happy to help you determine whether this is what’s happening to your system and find cost-effective solutions to keep your entire family warm. In this blog we’ll help you understand what short cycling is, plus detail some of its primary causes and how you can prevent them from cropping up.

Defining Short Cycling

As we touched on above, short cycling refers to a situation where the furnace turns on and off more often than usual. The most common format is when it turns on for short periods, then turns off in a stop-and-start cycle that lasts the entire day.

There are a few negatives that come with short cycling, starting with the way they can increase your heating bill. Short cycling often takes place because the furnace is too large for the home (more on this below), which can also cause major issues of overheating that costs you hefty sums. In addition, short cycling puts significant strain on the furnace and other HVAC components, including vents, all of which may wear down faster and require expensive replacements sooner than usual.

Addressing Causes of Short Cycling

There are several possible causes of furnace short cycling to be aware of:

  • Filter issues: Perhaps the most common source behind a furnace short cycling is filters in the furnace that have not been changed often enough. Filters are meant to draw impurities out of the air before it reaches you, but if they’re left too long, they’ll build up blockages and will actually stop air from passing through the heat exchanger properly. In turn, this will overheat the furnace and activate its automatic shutdown feature, beginning the short cycle pattern. Change your filters regularly to avoid this.
  • Furnace size problems: As we noted above, furnaces that are too large will heat your spaces too quickly and then turn off. If installing a new furnace, speak to our staff about selecting the proper size and capacity.
  • Thermostat concerns: In other cases, a faulty thermostat is the cause of short cycling. Some thermostats deal with built up dust or gunk over the years that may mess with their circuits, while others might simply be low on batteries and not functioning well. Another potential thermostat issue: Thermostats placed too closely to a heat source, meaning they mistakenly think the home is properly heated even when it’s not.
  • Insulation problems: In some cases, short cycling takes place due to air leaks that allow warm air to escape too quickly. This forces the furnace to start back up again sooner than it should. Check regularly for leaks in insulation, plus in door and window areas.

For more on avoiding furnace short cycling, or to learn about any of our HVAC or plumbing services, speak to the staff at Action Plumbing, Heating, Air & Electric today.