How Often Should the Heat Run When it’s Below 32 Degrees?

Cold weather tests your heating system. In the Carolinas, you’ll probably go months without running the heat. Then in March or April, you might have weeks, or days, when you alternate heat and AC within a few hours of each other. When a home’s heat is on and cycling, when does cycling too much mean you have a problem? How often should the heat cut on and run when it’s below 32 degrees outside?

The Heat Should Cycle

The best answer is – it depends. Heating systems cycle on and off a wide range of times, from 3-8 times an hour. This range depends on many things. The climate, the HVAC system itself, a home’s build and insulation, and if you’re changing the thermostat, all these are variables that can be more of a role than any issue or problem. There are times, though, when your system shouldn’t be cycling as often as it is and it’s indicative of a problem.

Is Your System Short Cycling in the Cold?

Cold temperatures will mean your home’s heat is on more, that’s expected. The furnace or heat pump will be on more. Still, even when it’s freezing, your heating shouldn’t cycle on and off every few minutes, then again, then again. A heating cycle should last until the house reaches the temperature you’ve set.

If your system seems inefficient, and it’s cold, but not Arctic cold, out, it makes sense to check a few things. How is the home’s insulation? Is the heating system getting up there in years? You can check doors and windows to see if you’re losing heat in those spots. Check filters and other easy, but often ignored, maintenance you can do yourself.

How Often Should the Heat Run and at What Temperature?

There’s not one exact answer. It depends on where you live, the size and rooms of your home, the humidity, and even just how you personally like it. It can also vary with how much you are in the house, if you have young kids, if your property is largely in the sun or shade and at what times of the day, how you like to sleep, and more factors.

Weather in the fall and spring can change in a blink, sometimes multiple times within 24 hours. You can feel cold when you wake up before the sun’s up, then need the AC for most of the day.

Here are a few subjects to think about for turning the heat on while also saving some energy.

• The Indoor Temperature – The World Health Organization (WHO) has standards for what’s considered a healthy temperature. It states the minimum indoor temperature should be 64.4 degrees. It says the ideal temperature for a building with children or seniors is 69.8 degrees.
• Your Preference – This is how you and your family like it. If you don’t mind the cold, then you can adjust accordingly. If no one’s home during the day, it changes how you can run the heat. Maybe you’re fine with extra layers of clothing, extra layers on the bed, and so on, it’s your home and your preferences.
• Sleep Setting – This can go either way. Some people want it warmer through the night. Some are fine with warmer bedding, and letting the thermostat be a little lower overnight.
• The Home Itself – Your HVAC system matters to the whole house, as in the house and other systems and components. Parts of a building – wood, insulation, brick, upholstery, attics and basements, or crawl spaces – are made to last best in a certain range of temperatures. The heat keeps materials such as these drier. Too much moisture staying in a home for too long can lead to health and safety issues.

Potential Problems

If you find your heating system is cycling too often, it might be one of the issues causing it.

• The System is Old

How old is your heating system? As the system grows older, you may discover the heater cycling on and off a lot more often. Generally, heating systems last about 15-20 years. As it gets to the upper end of its lifespan, it might not run as efficiently as before. Short cycling is a pretty good sign it is time to purchase a newer model.

• The Furnace and the House Don’t Match

A bigger heater isn’t necessarily the right answer. It needs to be the right size for the house. Short cycling can be a result of an undersized system or an oversized system. Shouldn’t a large heating system heat a house better and faster? Not always.

While a large heating system will heat a smaller space faster, it won’t uniformly heat all the space or rooms. The system will cycle off too soon to keep the temperature equal throughout the house.

Which size is the best for your home? Energy.gov suggests 12,000 BTU per 400-500 square feet, however, this number might change based on your house’s insulation and the area’s typical climate.

• The Heater is Overheating

When it’s very cold, as in below freezing, outside, your heater could be burning up inside. Getting too hot is a leading root cause of heating system short cycling. What triggers overheating? In numerous instances, poor airflow is the issue. Blocked, clogged, broken, or dirty ducts, or a dirty, old filter, can make airflow poor and create all sorts of larger problems.

• Check Your Thermostat

The thermostat tells the whole system when to cycle. The thermostat could be malfunctioning. It could be set wrong. Was there a power outage and reset? Where the thermostat is can be important, too. The thermostat shouldn’t be set in direct sunlight or in a place that is too close to a heating or cooling source or vent. This can lead to readings that aren’t good readings for the whole house.

• Check the Flame Sensor

Does your furnace cycle back and forth for just a few seconds each cycle? It could be from a dirty flame sensor. A clean sensor regulates cycles right. Just as vital, it’s also a sensor of very dangerous gas leaks in a house.

At South End Heating and Air, we specialize in HVAC and furnace repair, call us for a free consult. We’ll evaluate your system and help make recommendations for optimum value. After all, we want to keep you cool all summer long and warm in the winter. Just schedule a visit with one of our technicians to talk about how we can help with your heating needs. Would you like to learn more options our techs can help you with? Give us a call 704-684-5339.