Resetting a furnace essentially means you’re turning it off and back on again. It’s a simple solution in many cases and can avoid having to call a heating contractor. How you reset the unit depends on the situation and the model you have. We’ll look at how to reset a furnace to restore heating in your home.
Reasons a Furnace Reset May Be Necessary
There are a few reasons your furnace may need to be reset during the winter season. Some of the causes of a furnace shutdown include:
- The unit is too hot
- No fuel in the system
- Closed gas valve
- Faulty flame sensor
- Electrical disruption
Where Is a Furnace’s Reset Button?
The reset button’s location depends on the make and model. It is usually located near the blower motor in a central heating and cooling system. If you’re not sure where your furnace’s reset button is, check the owner’s manual for a diagram of its location or instructions for finding and using it. The reset button is typically yellow or red.
However, newer furnaces are designed differently than older models. You may just need to find the power switch mounted on or near the unit and turn it off. If you can’t find it, you can turn off the power at the main circuit breaker panel. Then wait 10 seconds before turning the switch or breaker back on. The furnace should start up again.
Steps to Resetting an Older Furnace
If your furnace has turned off and the reset button has popped out, how you proceed depends on your furnace model. Resetting a furnace that’s over 30 years old can be a bit more complicated. First, check the pilot light. If it’s on, fixing whatever is wrong doesn’t require resetting the furnace. However, a furnace reset will be necessary if the pilot light is off.
In this case, proceed with the following steps:
- Turn Down the Thermostat: Set the thermostat to its lowest temperature setting. This will protect you against a blast of hot air should the furnace unexpectedly turn on during the reset process.
- Access the Pilot: To reach the pilot light, you’ll have to remove the access panel. Depending on the model, you may have to lift and remove the panel.
- Light the Pilot Light: Hold a lit match, a small lighter, or a barbecue lighter to the opening where the burner flame usually is. Remove it once the flame catches.
- Set the Thermostat: For your furnace to kick in, turn the thermostat up to the desired temperature. The system should then start working and producing heat.
Restarting a Gas Furnace
Follow the steps above, but if your furnace is gas-powered, you’ll also need to turn off the gas control valve and wait for the gas to dissipate. After five minutes, turn the valve back on; this prevents a fire, but you must work quickly (any delays mean you have to start over again). Turn the power back on and the furnace should start running normally within a couple of minutes.
Resetting a Furnace After a Power Outage
You may be tempted to hit the reset button after the power comes back. However, it’s better to check the thermostat first. Turn it on if necessary and switch it to heat or the automatic fan setting. Or, if it’s on, proceed with resetting the thermostat. If your furnace is connected to a GFCI outlet, check if the outlet tripped during the outage. Reset the outlet and see if the furnace turns on.
Remember, when you press the furnace’s reset button, press it only once; otherwise, a safety lock will engage, preventing the unit from starting. The unit must be looked at by a professional if it won’t work after a power outage.
When to Call a Heating Professional
How to reset a furnace is usually simple. However, there may be times when the unit doesn’t turn on or doesn’t work properly. Contact a heating professional if you experience any of these common heating problems:
- No heat is produced
- The air isn’t warm enough
- Uneven heating in your home
- No air comes from the vents
- The blower runs constantly
- Rattling, squeaking, or rumbling noises
- A musty or burning smell from the furnace
Contact Monarch Home Services
If you’re still wondering how to reset your furnace, after trying the steps above, you can continue to try troubleshooting the problem. But if the unit isn’t working right, our NATE- and EPA-certified heating repair technicians can diagnose and fix any problem. They can repair gas-fired and electric furnaces and also service boilers, heat pumps, radiant floor heating systems, mini-splits, and ductless systems. For heating repair in Fresno, Bakersfield, and elsewhere in the San Joaquin Valley, call (661) 215-5851.