Furnaces typically run for about 10 to 15 minutes in moderate weather. Extreme cold can result in longer cycle times. Positive and negative factors that can affect furnace run time include: Sizing: A furnace correctly sized for
It's common for your furnace to kick on more frequently in cold weather. While it's okay if your furnace cycles on and off several times every hour, it shouldn't cycle on and off more than 8-10 times.
While it should cycle throughout the day, clicking on too frequently may indicate a problem. Homeowners often find themselves wondering, "How often should my furnace cycle?" The answer lies in a gray area. On average, furnaces should kick on and turn off anywhere from three to eight times per hour.
If your furnace shuts off after 15 minutes, a dirty air filter is likely blocking your heat. It's important to change dirty air filters at least every 90 days to avoid harmful debris build-up that obstructs your system's functions and distributes unhealthy air throughout your home.
Reasons why your furnace keeps turning on and off:
Temperatures outside of home. Improper insulation. Faulty thermostat. Dirty flame sensor.
Each furnace's “normal” heating cycle run time differs based on the size and type of furnace, your home's square footage, and the desired indoor temperature. Furnaces typically run for about 10 to 15 minutes in moderate weather. Extreme cold can result in longer cycle times.
Blocked vents or a clogged air filter may cause your furnace to run and then shut off too early. It's easy to fix these issues on your own. You should change your furnace filter at least once every three months. Follow our guide to do it yourself.
As long as the furnace is running efficiently and not making strange noises, the constant operation is likely nothing to worry about. But in general, your furnace should not constantly be running. Otherwise, it could indicate a problem with your heating system.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
One of the leading causes of short cycling is an oversized furnace. If your heating system is too powerful for your home's heating demands, it will quickly heat your living space, causing the thermostat to reach the set temperature and signal the furnace to turn off.
In the heating, ventilation, and air conditioning (HVAC) business, short cycling is a phrase used to describe when a heater or air conditioner cycles on and off too frequently. It signifies a problem in your heating system's proper functioning and efficiency, in which it is not completing its heating processes.
If your thermostat is not working properly, it may not be able to accurately read the temperature in your home or properly communicate with your furnace. This can cause your furnace to run continuously, even if your home is already at the desired temperature.
Pilot flame color changes
A yellow flame is a clear sign that the gas is not burning properly. Dirty or partially blocked systems can produce this. It's also another sign that a call to your trusted HVAC contractor is needed to save money and keep you a bit safer.
HVAC maintenance companies explain that a furnace will normally perform an average of two to three cycles in an hour, with each cycle lasting 10 to 15 minutes. But to keep temperatures at a comfortable level during cold weather, a furnace might need to increase this range to three to 10 cycles.
While all furnaces generate some ambient noise, they run quiet enough not to be disruptive most of the time. However, loud buzzing or humming can indicate various mechanical or electrical problems, either when the furnace starts up or throughout its operation.
You should turn your heat on when the temperature outside drops below 55 degrees. This will help you stay comfortable but also avoid costly heating bills. This is also the lowest temperature you'd want your house to get to avoid water pipes bursting.
But when your furnace won't shut off, the thermostat is often the first place to inspect. A common issue is incorrect settings. Make sure your thermostat isn't set to a constant “heat” or “on” mode, which can cause the furnace to run continuously.
One easy thing you can do to check the accuracy of your thermostat is to do a temperature check. See what your thermostat reads. Then use a portable indoor thermometer to compare the temps. Another good way to do the temperature check is to download one of the many free apps that allow you to check indoor temperatures.
Yes, a dying battery in your thermostat can have an impact on your HVAC system. If your thermostat's battery is low, it can cause your HVAC unit to function erratically or potentially not at all. Your thermostat plays a huge role in how your HVAC unit functions as it regulates the temperature of your system.
Filthy air filter
A dirty air filter is the most common cause of short-cycling. If the air filter is clogged with dirt, it won't allow proper air flow to the heat exchanger. That can cause the furnace to overheat and forces the high limit switch to ride to the rescue by shutting the furnace off.
Generally, a furnace cycle lasts anywhere between three to 10 times every hour; however, the frequency changes depending on several factors. If your furnace is cycling on and off more frequently than it should, there could be a problem with one of its internal components.
Having a dirty air filter in your furnace can cause short cycling. While a faulty flame sensor will lead to an immediate shut-off, a dirty filter will allow your furnace to run for several minutes and then shut down. You might notice that the air being pumped out of the heat grates is significantly hotter than normal.
The most common reason for short cycling is that the air filter is dirty and, therefore, non-functional. This is because the heat exchanger can retain heat to such an extent that it overheats. On the bright side, you will not have to look up “HVAC repair near me” as you can replace the filter on your own.