Why Is My Heater Not Working?

It seems like when the weather starts to get cold, that’s when your car decides to stop producing heat. Or maybe your car hasn’t had heat for a while. Regardless, it can be miserable shivering in your car on your commute to work. It can also be dangerous if your defrosters are not working on your windshield. Before the polar vortex returns this winter, make sure that your heater is working the way it should.

The next time you go out for a drive, watch the temperature gauge on your dashboard. Does it show that your engine is getting warmer or is the needle always staying on cold? Also, when the engine has been running for a while, switch between the different vents to see if any heat comes out. Is heat coming out of the defrosters but not the middle or low vents?

If you are feeling brave, you can try and check the coolant hoses to see if coolant is being circulated. There are two hoses that connect to the heater, one inlet and one outlet. The coolant will not start flowing immediately after the engine is turned on. You will need to wait several minutes for the engine to heat up for the coolant to start working. You can see from the picture below where the hoses may be located. Check to see if you feel coolant is flowing through both hoses.

These are all things to note when trying to diagnose the problem. There are many other issues that could be the cause of having no heat in your car. For timing purposes, we will only highlight a few.

Low Coolant Levels

Did you check the level of coolant in your car? Hot coolant that is produced from passing through an engine flows into the heater core. The heater core is what is used to help heat the interior of your car. If the coolant levels are too low, the heater core won’t have enough hot coolant to get hot. Low coolant levels could also lead to your engine overheating because there isn’t enough coolant to cool off the engine. If you find that your coolant levels are low, you should add coolant right away before more problems start occurring.

Plugged Heater Core

If you were able to check your heater hoses and find that coolant is only in one hose and not the other? This may be a sign that your heater core is plugged keeping your coolant from circulating throughout the engine. This can occur overtime due to debris and corrosion blocking the flow of coolant into the heater core. The only way to fix this issue is to replace the heater core.


If the thermostat is stuck open, you will have cold coolant filtering through your engine. The thermostat is designed to prevent the coolant from flowing until the coolant reaches a certain temp. Also in very cold weather, it also helps maintain the best temperature for the engine. When the engine is at it’s optimum temperature it is more efficient. It runs smoother, gets better mileage because the fuel atomizes better so there’s less waste.


Is the heat not working in your car? We can find the issue for you. Feel free to give us a call and set up an appointment.

Spotlightautoservice.com specializes in European auto repairs and maintenance. We strive to keep our service cost 40% less than dealerships. Schedule an appointment for your Audi, BMW, Land Rover, Mercedes, Mini Cooper, or Volkswagen with us

Written by Spotlight Automotive