Furnaces, like most HVAC systems, might break down when you need them the most. The breakdowns are more infuriating when you’re certain you’ve adhered to your HVAC technician’s recommended maintenance timeline. This is especially true when the unit fails to turn on completely.
You’ll find yourself asking, “Why isn’t my furnace turning on?” As Greenwood’s trusted heating and cooling company, we’ve seen all the most probable causes. Some of these are easy to fix without hiring a technician.
We’ll cover all the details in this post.
Thermostat Problems
Thermostat trouble is one of the most common reasons furnaces refuse to turn on.
Your thermostat is the interface through which you communicate with your HVAC system. Your furnace should kick in when the mercury drops below a certain threshold. If it doesn’t, you should check the thermostat to confirm you haven’t made any mistakes with the settings.
First, confirm you’ve set the thermostat to heat.
Second, check the temperature you’ve set to confirm it matches the readings inside your home. If none of these are the problem, turn on the fan switch and check for a response from the furnace. If that doesn’t work, check the thermostat for an error code.
If there’s no error code, the problem lies elsewhere.
Gas Line Troubles
If you have a gas furnace, you already know it won’t work if there is no gas supply to the system. You can confirm that there’s no gas problem by examining the shut-off valve outside to ensure no one mistakenly turned it off.
Alternatively, you can confirm there’s no gas appliance problem by turning on another gas-burning appliance elsewhere in your home.
If the valve is open and other gas-burning appliances are working, you may have a blockage or disruption in the supply line to the furnace. For example, a leak in the line can make ignition difficult.
If you can perceive that unmistakable smell of a gas leak, we recommend holding off on looking for answers to, “Why isn’t my furnace turning on?” and requesting an emergency visit from an HVAC technician as soon as possible.
Electrical Problems
All furnaces need electricity to kick on, including your gas-powered system. Check to confirm that you haven’t accidentally switched off your furnace’s power disconnect switch. Turning the switch back on should resolve the problem.
While still on the electrical side of things, confirm that you don’t have a tripped circuit breaker. If you do, turn the breaker back on. Keep in mind that a tripped circuit breaker shouldn’t be a regular occurrence. If it happens frequently, you need to call an HVAC technician to find the underlying problem.
Faulty Furnace Flame Sensor
A dirty or broken furnace flame sensor will keep your furnace from lighting. One of the biggest signs of furnace flame sensor problems is that the furnace will click but fail to fire up.
If the sensor is dirty, carefully remove it from the furnace using a screwdriver and clean it with a soft cloth. Be careful to avoid breaking it and also to return it the way you found it.
If cleaning the sensor doesn’t solve the problem, you’ll need to schedule a furnace repair service for a more in-depth diagnosis.
Blockage in the Condensate Drainage Tube
Do you have a high annual fuel utilization efficiency (AFUE) furnace? The condensate will drain outside via a plastic tube. If there’s a clog in the tube, the water can’t drain. The float in the drain pan will shut down your furnace in that scenario until you clear the clog.
You can easily complete this by connecting a wet/dry vacuum to the tube’s exterior opening and then sucking out the materials causing the blockage.
Contact Complete Comfort Heating, A/C & Plumbing Repair In Greenwood, Indiana, To Get Your Furnace Working Again
An unresponsive furnace is one of the biggest frustrations you can face as a homeowner. However, before you start to tear out your hair while wondering, “Why isn’t my furnace turning on?” be sure to check out the troubleshooting tips we’ve covered here first.
In many cases, you should be able to get your furnace working properly again without requesting professional help. However, if you’ve done your best and can’t get the system working again, we’re here for you! We can fix all common causes of unresponsive furnaces.
We are also the team to trust when your furnace is making noise during operation.
Call the Complete Comfort Heating, A/C & Plumbing Repair team in Greenwood, IN, today at (317) 316-8724 to schedule a consultation.