Reasons Why Your Furnace Is Not Coming On
What is my furnace doing?
Before diving into finding a solution for why your furnace isn’t working properly, it’s helpful to have a better understanding of what your furnace is or isn’t doing. There are a few ways in which your furnace may be malfunctioning, including A., the furnace is turning on but there’s no heat, and B., the furnace simply isn’t turning on at all. Knowing which of these is the case will help you determine the possible problem and its solution.
Furnace comes on, but there’s no heat: You notice that your house isn’t as warm as it should be. You check the thermostat and, sure enough, the actual room temperature isn’t as high as what it’s set to be. You adjust the thermostat and you can hear your system kick on, but notice that there’s no warm air coming out of the vents. In this case, it will be helpful to start by checking the furnace’s pilot light and air filter. These are also good things to check if you do feel warm air, but notice that the system is shutting off before the temperature reaches what it is set to reach.
Furnace does not come on: It can be incredibly frustrating to have a chilly house and a furnace that refuses to come on, especially when the thermostat appears to be set properly. In this case, in can be helpful to take a look at your breaker box and the furnace’s service switch to get a closer look at why your furnace isn’t functioning properly.
Why is my furnace not coming on?
Whether your furnace is turning on but not producing heat or it isn’t kicking on at all, there are a variety of issues that could be causing the malfunction. These issues might be located within the furnace itself, or in other parts of your home. When looking for a solution, consider the most common reasons first. If your furnace still won’t work, there are additional steps you can take to get your furnace up and running again.
The thermostat isn’t on
Having the thermostat on the proper settings may seem like an obvious requirement. However, if you’re having issues with your furnace, taking a look at your thermostat will help you quickly eliminate – or fix – a possible cause for your furnace troubles. First, be sure that the thermostat is turned to the heating setting. Then, make sure that the temperature is turned up high enough to cause the furnace to kick on. You can also open the thermostat to clear out any debris that may be there and interfering with the system. Since the thermostat tells the furnace when it needs to turn on, checking the thermostat is a great first step in troubleshooting furnace problems.
The pilot light is out
The pilot light is a small blue flame that is meant to remain lit. It’s typically found in older gas furnaces, whereas newer furnaces tend to have electric igniters. When a furnace kicks on and is working properly, gas will flow into the furnace’s burners and the pilot light will ignite the gas. However, sometimes the pilot light goes out, which can be caused by even a slight breeze. When the pilot light goes out, it causes gas to stop flowing and prevents the furnace from turning on.
To re-light the pilot light, turn the gas valve switch to ‘off’ and wait approximately 3-5 minutes to ensure there’s no buildup of gas. Then, turn the switch to ‘pilot’ and press and hold the reset button while lighting the opening of the pilot light using a long lighter. Once the pilot light is lit, let go of the reset button and turn the gas valve switch to ‘on’. If this is something you don’t want to attempt doing yourself, a heating and cooling professional will also be able to do it for you. If the pilot light continues to go out, it may be a sign of other issues that a professional will need to look into.
There is no power
Another possible reason that your furnace isn’t coming on is that it’s not receiving power. To remedy this, find your circuit breaker and check for a blown fuse. If the switch for the furnace was moved to the ‘off’ position, move it back to ‘on.’ Even if you find the switch to be in the ‘on’ position, you can still try moving it to ‘off’ and then back to ‘on’ just to be sure that the fuse isn’t causing problems. If this doesn’t solve the issue, look for the furnace switch on your furnace. This switch may look like a standard light switch, and controls the power to your furnace. Be sure that it is flipped to the ‘on’ position.
The gas supply was turned off
The gas valve needs to be on in order for a sufficient amount of gas to flow to the furnace, allowing it to function properly. If your furnace won’t come on, check to make sure the gas valve switch is entirely in the ‘on’ position. You can also check that the gas line to your home is on by looking at the shut-off valve outside of your house.
The air filter is dirty
When is the last time you cleaned your furnace’s air filter? If it’s been a while, a dirty filter may be to blame for your heating troubles. When a filter is excessively dirty with dust, debris and germs, air isn’t able to flow through as well as it needs to be and your furnace may begin acting up. If your furnace isn’t coming on, try checking to see how dirty or clean the air filter is. If it’s visibly dirty, make sure to replace it. This will also help ensure that the air circulating through your home is clean. A furnace air filter typically needs to be replaced every few months, and sometimes more frequently in the winter.
Additional furnace issues
If you’ve already checked the typical culprits such as the pilot light, circuit breaker and filter and your furnace still isn’t working, you may need to take a closer look at some specific areas of the furnace. Here are some additional reasons that your furnace may not be coming on.
- The blower motor isn’t working: The blower motor turns a fan inside of the furnace to push warm air out and help circulate it throughout your home via air ducts. However, if the blower motor has stopped working properly, it can cause your furnace to stop working properly as well.
- There’s condensation: When your furnace is working, moisture in the air may collect in the furnace’s condensation pan. If this pan is not draining properly, it can cause problems with your furnace. Check to see if this pan is full and if there is anything blocking it from draining.
- Hidden issues: It’s also possible that there are issues with your furnace that you won’t be able to see from the outside, such as parts that are overheated, broken, or for some other reason aren’t functioning correctly. For these issues, it will be necessary to hire a heating and cooling professional to further investigate the problem.
If your furnace is still not working
Trying to get a furnace to work when the problem seems impossible to find can certainly be aggravating. If you’ve checked your furnace for all of the previously mentioned issues and can’t find the culprit, there are a few next steps you can take. One option is to take a look at some items in other areas of your home to see if they’re causing problems for your furnace. The other option is to call a heating and cooling company and have them send a pro to your home to further investigate the issue.
Look throughout your home: If your furnace still seems to be malfunctioning, check the air vents in each room to make sure all of them are open and not preventing warm air from flowing. Air ducts that are blocked or leaky prevent air from properly flowing, so check that there is nothing in the way and that there are no holes. It may also be helpful to go outside and check that there is nothing in the way of the exhaust vent, air intake vent, or the heat pump.
Hire heating and cooling professionals: If you have gone through this list of potential issues and still can’t figure out why your furnace won’t turn on, it may be time to hire an HVAC professional. This is also a great option for people who simply don’t want to try to fix their furnace on their own. The right professionals will have the proper tools and knowledge to find the issue and repair your furnace.
If you’re in the Ashville or Columbus, Ohio areas, Legacy Heating & Cooling is a great choice for when you’re dealing with furnace problems. We’re a family-owned company that operates with the mantra of “our family serving yours,” and we strive to provide courteous, professional service to each and every customer. Our experienced, factory-trained technicians are able to diagnose and repair your equipment to satisfaction and will never push you into expensive, unnecessary repairs. We also look to fix the root of your issues rather than applying a Band-Aid that will end up costing you more over time. Our high-quality services include heating installation, repair and maintenance as well as air conditioning installation, repair and maintenance.
We believe the only way to separate ourselves from other HVAC companies is by the services we deliver and the legacy we leave behind. With our warranties, reasonable prices and devoted staff, we know you will be satisfied when you choose us as your heating and cooling service provider.
Having your furnace stop working is never ideal, and even less so if it happens during the cold winter months. Fortunately, if you do experience this, there may be an easy fix to get your furnace back up and running quickly. If the issue is more complex, a trained heating and cooling specialist is just a call away.