Table of Contents
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.
How do I stop my furnace from short cycling?
The easiest way to fix a furnace that is short cycling is to remove the flame sensor to clean it. Use a sponge or brush to remove the dirt from the sensor. After the part is clean, follow the manufacturer’s instructions to insert the flame sensor into the furnace.
Why does my furnace turn on and off every few seconds?
A common reason a furnace short cycles is because the heat exchanger, the part that heats your air, is getting too hot due to a lack of airflow. Once the heat exchanger overheats, it trips the high limit switch, which shuts the furnace down to protect it.
Is it bad for your furnace to short cycle?
Short cycling is when the furnace turns on for a short period of time but then turns off. This start-and-stop cycle can keep your home from properly warming up and may also damage your furnace itself.
How often should a furnace cycle on and off?
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.
How do you know a thermostat is bad?
7 Signs You Need to Replace Your Thermostat Your HVAC Keeps Turning On or Off. Faulty Thermostat Readings. Suspiciously High Energy Bills. Constant Temperature Shifts. Thermostat Is Too Old. Thermostat Fails to Respond to Changed Settings. Your HVAC System Short Cycles.
How do I stop short cycling?
How To Stop and Prevent Short-Cycling Check your air filter. Believe it or not, a clogged air filter can cause a wide variety of air conditioning issues. Check your thermostat placement. Check your air conditioner’s refrigerant levels. Replace the low-pressure control switch. Check the compressor.
Why is my furnace coming on every 5 minutes?
Heat Vents are Shut. While a contaminated air filter doesn’t let enough air in, heat vents that are shut do not let the air out. If your furnace runs every 5 minutes, then this could be the problem. This has an easy fix—simply ensure that 75% of your heat grates’ dampers (the vents in each room) are open.
Why won’t my furnace shut off?
If your furnace won’t turn off, the easiest issue to fix is your thermostat. A furnace that is working hard to keep a high temperature, especially when it’s extra cold outside, can seem to run continuously. The second common thermostat problem is the fan switch. Your fan can be adjusted manually from your thermostat.
Why does my furnace keep running?
A dirty furnace filter is the number one reason we’ve found that furnaces run constantly. The air filter captures dust, pet hair, and debris that could damage the furnace and keeps it from getting to the heat exchanger. If the filter is dirty, it restricts airflow across the heat exchanger, which causes it to overheat!Nov 24, 2015.
Why is my furnace kicking on every 10 minutes?
A dirty filter doesn’t let enough air in. This problem doesn’t let enough air out of the system. Short cycle time: 3-10 minutes. Again, the furnace will stop before your home is warm.
Can a thermostat cause short cycling?
A faulty thermostat can be a possible culprit for short cycling. If you’re experiencing a furnace short cycling, the first and easy thing you can do is check your thermostat to see if it’s performing correctly. Many times, a homeowner may forget to switch their thermostat over to the heating mode.
How do I test my furnace thermostat?
How to Test Your Furnace Thermostat Step 1: Reset the thermostat lower or higher. Step 2: Make sure the thermostat is ON. Step 3: Check the wiring. Step 4: Turn breaker back on. Step 5: Reexamine wires. Step 6: Wrap wires together.
How do you tell if you need a new thermostat in your house?
Signs You Need a New Thermostat Heating or cooling system will not turn off or on. The temperature reading is incorrect. Recent spike in your energy bill. Frequent temperature fluctuations. Thermostat is 10 years old or older.
What is considered short cycling for a furnace?
A furnace “short cycles” when it turns off before reaching the desired temperature. This means that if your thermostat is set to 72 degrees, the furnace may shut down at 65 or 68 degrees, but will never reach 72 degrees. Short cycling can also be used to describe a furnace that turns on and off too often.
What causes short cycle?
As we said above, short-cycling is often the symptom of a problem—this problem could be from any of the following circumstances: A clogged air filter. An oversized or undersized air conditioner. Low refrigerant charge due to leaks.
What is considered short cycling?
Short-cycling is a term for when an air conditioner shuts down its cooling cycle prematurely, only to start back up again a short time later. If you have noticed that your air conditioner’s compressor is turning on and off rapidly, it is probably short-cycling and you need to have it repaired.
