A furnace cycling on and off repeatedly can be caused by various reasons, from dirty filters and obstructions in ducts and
If your furnace keeps turning off and on, your thermostat may be the culprit. A malfunctioning or improperly placed thermostat can cause your furnace to short cycle. Common issues include: Old wiring or dead batteries: Replace batteries or old wiring to ensure accurate temperature readings.
This event may occur when your furnace is not receiving adequate air flow thus overheating it. Therefore, ensure to check the air filters and the vents to ensure there is proper airflow. Make it a habit to check the air filters and take necessary actions if needing to clean or replace them with a completely new set.
The simple solution: Turn your furnace off and check the filter. If it's dirty or it's been 3 months or more since you changed it, put a new, high-quality filter in place.
The major issue that can cause this problem is a heat exchanger issue. If your furnace is cycling off on high limit, and everything checks out, you may have an internal blockage of the heat exchanger. If this is the case either the heat exchanger or the furnace will need to be replaced.
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.
A furnace cycling on and off repeatedly can be caused by various reasons, from dirty filters and obstructions in ducts and registers to incorrect thermostat settings and faulty limit switches. By following the steps above, you can help prevent your furnace from cycling too frequently and save energy costs.
Your thermostat could also cause the HVAC system to cycle on and off rapidly, a process known as short cycling.
On your thermostat, look for the fan settings. There should be two, “ON” and “AUTO.” If it seems like your furnace won't turn off, the thermostat may be set to “ON” for the blower. Toggle the switch to “AUTO” so your furnace's blower fan only runs during a heat cycle.
Overheating is the number one cause of reset button trips. If your furnace is cloistered somewhere where there isn't enough airflow, it may become overheated repeatedly, leading to frequent reset button trips. No Fuel.
Ask twenty professional HVAC contractors the question, “How Much Does A New Furnace Cost?” and you'll probably get the same answer... “It depends.” On average, the cost of a new furnace can range from $2,000 - $14,2001. However, factors like furnace efficiency, type, size, and much more can impact this range.
If a furnace isn't receiving enough airflow, it may overheat and trigger the reset button to trip. Make sure to clean or replace the air filters and keep the air vents open enough for proper airflow. Occasionally, the flame sensor rod may be coated with dirt and debris, causing the furnace to shut off.
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.
Short cycling is a common sign of a bad flame sensor. The sensor thinks that there isn't a flame, so it shuts off the gas as a safety mechanism. Except, there is a flame and without the gas to supply it, it dies. This is a frustrating problem, but an HVAC technician can fix it.
If you have a dirty or clogged air filter, change it right away and see if short cycling stops. You can buy most replacement filters at your local hardware store. To prevent short cycling from happening again, be sure to change your furnace filter every 90 days.
A heat exchanger replacement is often one of the most costly repairs in a furnace, and the expense can sometimes rival that of installing a new furnace. Typical replacement costs vary widely but can easily reach several thousand dollars, especially if labor costs are factored in.
A clogged furnace air filter will negatively affect the airflow throughout your house and HVAC system. The lack of fresh air in your furnace will cause the heat exchanger to become too warm and deactivate. Dirty filters indirectly cause short cycling issues and will make it hard to keep your home warm.
The Dangers of Short-Cycling
Customers often ask, “Is furnace short-cycling dangerous?” While short-cycling isn't inherently dangerous, it can reduce energy efficiency, cause safety problems, and increase wear and tear on your home's HVAC system.
When gas gets built up in a new furnace it may shut down for extended periods of time until it can be reset to try again. Some older furnaces may not have this and could cycle off and on as gas is built up. This switch turns your furnace off if gases are not properly ventilated out of the exhaust flue.
There are multiple reasons why your furnace is short cycling. These could include a dirty filter, blocked vent, or malfunctioning flame sensor. You can switch for a clean furnace filter, or have your HVAC technician resolve a more complicated issue.
Malfunctioning Blower Motor
If it's not working correctly, the airflow will be restricted, causing the AC to cycle on and off more frequently. This can be a problem because it stresses the compressor, leading to a complete system failure.
The common sources of a furnace clicking sound are:
If it's faulty or dirty, it won't send the signal and the ignitor will click. Ignitor flame — The flame itself can run too cold to burn the gas or oil effectively, so the ignition clicks for several minutes or unendingly.