Press the reset button, it is usually red. You may have to hold it for 30 seconds. Turn the power back on for the furnace. Now put your thermostat back to your typical temperature.
When a furnace overheats, immediate action is vital. Homeowners should shut off the furnace and contact an HVAC professional for emergency repairs. While common fixes may include replacing faulty parts, long-term solutions like regular maintenance or replacing an aging unit can prevent future overheating issues.
Either way, restarting a furnace is a relatively simple task that takes no longer than 10 minutes to complete.
Typically, you'll find it inside the air handler, either next to or above your furnace. In most newer systems, the button is often directly next to the blower motor, while in older systems, it may be harder to spot as it is sometimes underneath or behind the motor.
Steps to Reset Your Furnace
If you can't find a switch at the furnace you can turn off the circuit breaker to the furnace at the main circuit breaker box. Wait about 10 seconds. Turn the switch or breaker back on and check the furnace to see that it has power again.
If nothing's happening when you're expecting the whir of a blower, check the circuit breaker and fuse. At your electrical panel, make sure all switches related to the HVAC system are on. Reset any tripped breakers and replace all blown fuses, and your furnace should kick back on.
It may be required if the furnace becomes overheated or if the electrical grid gets disrupted. Just hit the reset button again to get the heating system working again. However, if you press the restart button and your furnace turns off once again, pressing the reset button again can cause severe damage to your furnace.
A furnace motor can overheat in various ways. Here are the most common risks: A clogged filter can impede airflow and force the motor to work longer. Sooner or later, the motor might overheat, increasing the risk of fire.
Cooling can be achieved by opening the door of an oven or chamber furnace, but it is generally not recommended to do this from high temperatures for standard products. Large custom built retort furnaces can be designed so the panels of insulation can be opened to speed up cooling, which could be located in the roof.
All modern furnaces have a furnace limit switch. The switch, which works in tandem with the blower to ensure the appliance is at a safe temperature, will turn off the burners if the temperature gets too hot, only letting them start again when it's safe to do so.
Check Your Circuit Breakers: Even if you use a gas or propane furnace, some of the components run on electricity. If your furnace doesn't switch on, the circuit breaker could be shut off. Check your circuit breaker panel to make sure all switches for your HVAC system are set to “ON.”
Turn off your air conditioning system. Locate the reset button on the thermostat's circuit board. Use a soft bristle brush to gently remove any dust or debris that may have accumulated on the thermostat components. Press and hold the reset button for 5-10 seconds until the display goes blank.
Checking your thermostat is the best place to start. Make sure it's set to “heat” and that you've set the temperature higher than the current room temperature. If that doesn't resolve the problem, try switching your fan to “on” to force the furnace to start working.
There are several reasons why your furnace may not turn on. The most common include a broken thermostat, gas line issues, clogged air filters, blocked ductwork, a tripped circuit breaker, and issues with the furnace itself.
A furnace that won't turn on is one of the more obvious signs of a blown fuse. No matter how much you change your thermostat settings, your furnace just won't respond. Once you realize your furnace won't respond to thermostat commands, you may need to dive deeper to find the problem at its source.
The purpose of the reset button on a furnace is to shut it down before it can trip your circuit breaker. The need for this may arise if the furnace becomes too hot, or if there is some sort of electrical system interruption.
Check Furnace Thermostat Settings
Incorrect thermostat settings can be the cause behind no heat coming out of the vents, even with the furnace blower turned on. Check the thermostat to ensure the setting is in HEAT instead of COOL. It is a common mistake that happens. The fan runs continuously when it is switched on.
When this occurs, often after two or three failed restart attempts, the furnace is known to be in lockout mode and will not attempt to run again until the furnace is manually reset. It is important to note that there are soft and hard lockouts, which does vary by manufacturer.
Gas Furnace - The emergency switch is typically a red switch located on or near the furnace unit. It may be mounted on the side of the furnace or on a nearby wall. Heat Pump - The emergency switch for a heat pump is typically a red switch located near the outdoor unit. It may be on the unit itself or on a nearby wall.
Reset the AC Using the Isolation Switch
You can find it on the wall beside the unit or at the condenser. The isolation switch looks like an ordinary light switch with a knob. Once you locate it, turn the knob to the off position and leave it for at least 30 minutes up to an hour.