When your furnace shuts down, resetting it can avoid calling a heating services company. Do you know how to reset a furnace? The reset button provides an easy way to resolve common issues. Every furnace has one to turn the unit off when a problem is detected. It can also save you time and money.
If the reset button keeps tripping, it’s time to call a furnace repair contractor. However, let’s assume this is an isolated occurrence and explore how to reset a furnace using this helpful feature.
Why Does My Furnace Have a Reset Button?
The furnace reset button is included for safety reasons. It is usually red or yellow and located inside the blower compartment. The button is designed to trip before the circuit breaker.
It’s not uncommon to have to reset a furnace occasionally. Doing so avoids paying a contractor’s service fees when there isn’t a significant problem to fix. The process is also easy for most homeowners.
Steps to Resetting a Furnace
Gas, oil, and electric furnaces all have a reset button. The following tips will help you locate and use the button to get your furnace working again or help you determine whether to call a heating professional:
1. Locate the Reset Button: The exact location can vary based on the furnace make and model. It’s usually on the blower motor in a central heating system. If it has tripped, the red or yellow button will stick up about half an inch (normally, it sits flush within its housing). In other systems, the reset feature is located near the bottom and back of the motor. Electric furnaces often have it on the side of the motor.
2. Check the Pilot Light (Gas Furnace): If your furnace is operating normally, the pilot light will be lit. It should go out if the furnace turns off. Verify the pilot light is out before attempting to reset the unit. This avoids safety issues or damage when you start the system back up.
3. Check the Oil Supply (Oil Furnace): When an oil furnace stops running, check whether it has run out of oil. If so, call the oil company to inform them the tank is empty and request an oil delivery. A technician must visit and prepare the furnace before filling the empty tank.
4. Check for a Fuel Line or Valve Issue (Oil Furnace): If your furnace has an oil supply and the reset button trips, check if the fuel line is obstructed or a valve is closed. Open the valve if necessary. However, if there’s a fuel line or other problem, you’ll need a professional.
5. Turn Down the Thermostat (Gas Furnace): Reduce the temperature on the thermostat to as low as it will go. You don’t want the furnace to run at full blast the moment you turn it back on.
6. Turn Off the Power: Find the circuit breaker for the furnace in the main electrical panel and turn it off. This avoids any electrical hazards or surges that can damage the unit when you reset it.
7. Shut Off the Gas Supply (Gas Furnace): The appliance’s main gas supply should be turned off. Meanwhile, leave the pilot gas supply on so it has a fuel source to ignite once you begin the reset.
8. Relight the Pilot Light (Gas Furnace): Light a match or a lit long-neck lighter and reach toward the pilot light inside the furnace. Hold the lit flame near the pilot opening. The pilot flame should relight almost immediately.
9. Restore the Power/Gas: Once the pilot light is lit and any power supply issues are resolved, switch the furnace’s circuit breaker back on and restore the main gas supply.
10. Press the Reset Button: Hold the reset button for about 30 seconds. If you have a gas furnace, you can then turn up the thermostat to the desired temperature; the furnace should ignite (if not, call a local heating contractor). If you have an electric furnace, close the blower compartment cover and turn the power back on to see if the unit starts running.
Reasons a Furnace Reset Button May Trip
A furnace reset button may trip for several reasons. It allows you to restart the unit safely in the following situations:
- Overheating Furnace: The reset button may frequently trip if your furnace keeps overheating. In this case, the button is working properly. It’s protecting the system from unsafe temperatures. To address the problem, the unit’s ventilation should be improved or the furnace may need to be repaired. However, a lack of airflow is the primary cause of overheating.
- Fuel Supply Interruption: If the fuel tank is empty, it must be refilled before the furnace can be reset. An oil furnace trips when its sensors don’t detect flames in the burner chamber. Gas furnaces also shut down when there’s a low fuel supply or blocked line. The fuel source must be restored before the furnace is turned back on, or else the unit can be damaged.
- Closed Gas Valve: If the gas valve is closed, the furnace won’t receive the gas supply it needs to ignite and run properly. Check the gas valve whenever the furnace trips. If the system turns off repeatedly, the gas valve may have been accidentally closed and must be reopened.
- Faulty Flame Sensor: Dirt, soot, and debris can coat the flame sensor over time, causing it to malfunction. It may be so coated it cannot sense the flame. Therefore, the reset mechanism will trigger. The sensor must be cleaned or replaced before your furnace turns on again.
- Clogged HVAC Air Filter: The furnace reset button can trigger if the air filter is dirty or clogged. As air is pulled into the heating unit, it first passes through a filter that traps dirt and dust. This prevents particles from getting inside the unit. But trapped debris eventually clogs the filter, restricting airflow and increasing heat inside the furnace. The reset button shuts it down to prevent damage or issues such as a fire.
Other Tips to Avoid Calling a Heating Company
Knowing how to reset a furnace can help avoid making a repair call. Proper maintenance can also help protect your furnace and avoid inconveniences. Here are some tips for avoiding furnace shutdowns or having to call a heating company during an emergency:
- Check and clean or replace the air filter every 30 days (depending on the type of filter).
- Use your furnace less frequently or set the thermostat to about 68℉ in winter.
- Seal drafts throughout your home so your furnace doesn’t work as hard.
- Schedule repairs as needed, which reduces strain and helps your furnace last longer.
- Keep up with annual maintenance, which reduces performance issues and repairs.
When to Call a Professional
Assuming you know how to reset a furnace, but are not successful, you’ll need a trained technician to evaluate, diagnose, and address the problem. Do not try to reset the unit repeatedly. You can damage the system and expose yourself to safety hazards. The system may already need a repair, so delaying service can make the problem worse.
Contact Trilogy AC for Furnace Repair
Trilogy AC provides high-quality, professional furnace repair and other heating services in Katy, TX, and surrounding areas. Since 2012, we’ve been dedicated to the complete satisfaction of our customers and ensuring their comfort year-round. We also provide comprehensive air conditioning, ductwork, and indoor air quality services. Our membership programs include priority service, discounts, and annual equipment maintenance while competitive financing options are available. When you need a licensed, trained professional to diagnose and repair your furnace, schedule service online or call (832) 583-3194.
