Your Furnace Filter is Dirty A dirty filter is another reason your furnace can short cycle and overheat. If you notice that the furnace is shutting off after only a few minutes before your home is warmed this may be the cause. Another sign is that you feel hotter than usual air coming out of the heat grates.

How do I stop my furnace from short cycling?

Quote from the video:
Quote from Youtube video: So to fix this issue shut off your thermostat. And open up the furnace. And then replace the batteries on the thermostat.

Why does my furnace keep short cycling?





A dirty air filter is the most common cause of short-cycling. If your 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.

Can a bad thermostat cause a furnace to short cycle?

Thermostat Troubles Can Cause Short Cycling



Your furnace or central air conditioner spends a good amount of energy simply turning on and off, which is why you want yours to run for at least 15 minutes at a time before shutting off.

Why is my furnace kicking on every 5 minutes?

A dirty filter can cause the furnace to overheat. Short cycle time: 2-5 minutes. The key is that the furnace shuts off before your home is warmed. You might also notice hot air (warmer than usual) coming out of your heat grates.

How do you fix short cycling?

How To Stop and Prevent Short-Cycling

  1. Check your air filter. Believe it or not, a clogged air filter can cause a wide variety of air conditioning issues. …
  2. Check your thermostat placement. …
  3. Check your air conditioner’s refrigerant levels. …
  4. Replace the low-pressure control switch. …
  5. Check the compressor.





What does it mean when your furnace kicks on and off?

When a furnace keeps turning on and off, it is usually due to short cycling. This is the term used to describe problems originating from within the heating system. If short cycling is not promptly diagnosed and corrected, it could cause permanent damage to your heating unit and higher utility bills.

Can a bad flame sensor cause short cycling?

Bad Flame Sensor



Flame sensors are also subject to corrosion. This is because your furnace produces small amounts of water during the heating cycle. Over time, this can lead to corrosion and rust in your furnace, resulting in short cycling.

How long should a furnace run during a typical heating cycle?

10-15 minutes



With all that being said, if there are no extreme factors involved, the average run time for a furnace is 10-15 minutes per cycle. Your furnace may need to run two to three times an hour to maintain your desired temperature if your home has average insulation.

Why does my furnace turn on every 10 minutes?

Losing too much heat through the roof, windows, or doorways will cause your furnace to run more often. High ceilings and single-pane windows are common culprits. If your furnace only turns on for a few minutes at a time, but your home never warms up, it’s probably short cycling.

How many times should a furnace cycle in an hour?

On average, furnaces should kick on and off anywhere from 3-8 times per hour. However, if your furnace does so more frequently, don’t assume it’s short cycling just yet.

Can a bad blower motor cause short cycling?



Air handler defects ranging from a dirty air filter to dirty blower or wrong blower speed can prevent the furnace from producing enough heat rise across the heat exchanger, causing overheating and short cycling at the heating furnace.

How do you fix a short cycling heat pump?

Cleaning your unit, ductwork and air vents, as well as replacing/cleaning air filters can solve this issue. A Faulty Thermostat: Incorrect thermostat readings can cause your system to kick on and off at inappropriate times. This could be due to a broken thermostat or its placement.

Is short cycling normal?

One of the most common, and unfortunately harmful, problems an air conditioner can have is something called short-cycling. This is both a symptom of a problem and a cause of a problem. Sometimes a few simple adjustments may be all that’s needed to repair the issue.

Will low refrigerant cause short cycling?

Low Refrigerant



Another common cause of short cycling is low levels of refrigerant. Like a clogged air filter, low refrigerant can produce excess stress on your AC system and make it work harder. And it also causes overheating, which could lead to the frequent turning on and off.

Can too much refrigerant cause short cycling?



Watch out: an air conditioner or heat pump system that has been over-charged with refrigerant can also show up the problem as short cycling, rapid on-off cycling of the compressor motor.

What can cause the blower to come back on for a short time after cycling off?

Check for a dirty air filter and replace if needed.



A clogged filter limits the amount of cool air that passes over the heat exchanger, causing it to overheat and shut off. At the same time, your blower turns on to help cool it down.

How do I know if I have too much refrigerant?

Increased Heat Discharge – If you notice that your air conditioner is blasting extremely hot air from its vents, it means the unit has too much refrigerant and the system is producing extra heat. This is due to the motors being overworked by the overpowered condensing lines.

How do you tell if a system is overcharged?

In summary, there are seven symptoms or telltale signs of a system that has too much refrigerant.

  1. High discharge temp.
  2. High subcooling in the condenser.
  3. High pressures in the condenser.
  4. Higher condenser splits.
  5. Normal-to-high evaporator pressures.
  6. Normal superheats.
  7. High compression ratio.



How do you know if your refrigerant is low?

7 Signs Your AC Unit is Low on Refrigerant

  1. It takes a long time for your home to cool off. …
  2. Vents are not blowing cool air. …
  3. The temperature you set is never reached. …
  4. Your electric bill is higher than normal. …
  5. Ice on refrigerant lines. …
  6. Water leaking around heater. …
  7. Hissing or bubbling noise.


Can you add too much refrigerant?

Having too much refrigerant in your AC can damage the compressor. This can happen because the excess refrigerant will likely collect inside the compressor and cause subcooling, wherein temperatures are below normal. Furthermore, the extra refrigerant can flood the compressor and damage its mechanical parts.