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The last thing you wish for is a cold day in winter with a heater that is not working. Your house heater not working on that cold day when you need it the most can throw you into panic. There are several reasons why your heater could have stopped working. Some are easy to fix issues that you can try your hands on, and others can require HVC professionals to come through.
Read on to learn more about issues that can stop your heater from working and the steps you can take in order to bring it back on before calling HVAC professionals.

Why is My House Heater Not Working?
1)Check Circuit Breakers
The first thing you want to check when your heater isn’t working is the electric circuit breaker. If the breaker tripped, resetting it will solve the problem and should bring your heater back on right away.
But if your breaker keeps tripping, this can be a sign that a safety measure is in effect. There can be something seriously wrong within your heating system and the best thing to do at this point is to call a licensed HVAC technician who can come and asses the issue.
2)Furnace Power Switch
If your furnace is one of those that have an on/off switch, make sure the furnace power switch is not off. This is because many times, the swich is accidently tempered with. It is possible that you or other people that live with had inadvertently switched it off.
If you’ve had anybody such as an electrician or plumber do some works around your home near the furnace, it is possible they could have turned it off accidently.
3) No Heat in House: Thermostat Issues
The thermostat is the most common culprit for your heater not working properly. So always make sure you check the following when you are troubleshooting a house heater that is not working.
- Check that thermostat is set the temperature that you desire. Even when you are sure you set it to the right temperature, double checking your thermostat setting won’t hurt. With the growing trend of using smart thermostats among homeowners, it is frustratingly easy to adjust the thermostat by mistake on the mobile app. Sometimes, other folks that live or work with you could have adjusted the thermostat by mistake or intentionally and set it to their comfort. Temperature comfort varies from person to person.
- Dying or low battery on your thermostat: Your thermostat’s battery doesn’t have to be dead for your heater not to work. Low batteries can cause your thermostat to fail to turn on your heater. Replacing your batteries with new ones will definitely get your heater going again.
4) House Not Heating Up: Check Air Filters
After you have checked the power switch and the thermostat issue and the heater still won’t start, there is one more ‘easy’ fix and that’s to replace your air filters.
Clogged air filters will limit the air flow into your HVAC system. And in turn, will cause overheating within the heating system. When overheating occurs, the safety measures kick in to shut off the system then you’ll have no heating from your furnace.
In some HVAC systems, air filters are installed around the return vents. But other heating systems have filters in their furnaces.
Before checking the filters make sure you turn off your furnace. If the color of your furnace filter is mud, then is the time to replace your air filters. After you change filters close the door correctly otherwise the furnace won’t turn on.
5)Low Refrigerant Levels
If you use the heat pump system for your home heating, it could also stop working if the refrigerant levels become so low. The refrigerant levels can go down if there is a leak somewhere in the system.
When you do not recharge your heating system with more refrigerant, soon, the compressor could overheat and break down. Then you will have heat not working in house. This can lead to more costly repairs, so it is a good idea to call for HVAC repair service if you think your heating system has low refrigerant.
6) Flame Sensor Issues
When the flame sensor isn’t working properly it will cause your burner to shut off. A dirty sensor that is in grim will cut off the moment it comes on because it cannot sense the flame. However sometimes, it’s the burners themselves that get dirty. If your leave them without cleaning for a long time they will not work well. Regular furnace tuning on your HVAC system will prevent these issues. It’s best to tune your furnace atleast once on a yearly basis
7)Check For Blocked Ducts
Have you checked your ductwork? Are there leaks or disconnections anywhere around them? Ducts distribute warm air around your home. They are usually installed outside the heating area of your home. So, they can be exposed to extreme and changing weather conditions outside. Because of this, they are subjected to tear and wear. Leaking or clogged ducts could be the reason for your heater not blowing hot air or not working at all.
When there are leaks on the ductwork, the cold air surrounding the ducts can get into the ducts while the hot air can go out of them. This mix up lowers the temperature of that warm air been distributed around your home. Thus, all you can get is nothing but air that isn’t warm enough.
8)Dead Blower Capacitor
This is a component of the HVAC system that is responsible for starting your furnace. Once the set temperature on the thermostat is reached, the blower capacitor will turn on the furnace. Wondering what a blower capacitor is like? It is that part of the furnace that looks more like a big battery. If it is dying or dead, it can not start your furnace. This could be the reason your heater isn’t working. The best solution to this problem is to replace it. Before thinking of getting a new one, call professionals for advice.
Final Thought
Regular maintenance of your HVAC system can reduce the risk of unexpected break downs. These breakdowns can inevitably come at the worst moment possible, when you most need your heater. However, when you have a house heater not working, chances are, you can get it back on yourself without calling professionals to come and give a hand. If you are not comfortable with anything, it is in order to call for help.

HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.