Why Is My Car Heater Not Warming Up?


During this time of year in Somersworth, NH, car heating is necessary to be comfortable. When you turn your engine on in the morning, you may be hit with cool air at first. But, your car heater should kick in. If your vents are still blowing out cool air, then there is certainly something wrong with your temperature control system. 

Here are several most common explanations for why your vehicle’s heater is not warming up:

  1. Low coolant 
  2. Problem with the heater core
  3. Faulty thermostat
  4. Heating control errors

LOW COOLANT - Coolant is the solution in your engine that keeps it from overheating. Most people think that is all it does, but it plays a major role in supporting the heating system. If you’re low on coolant, the heater core will blow cool air instead. 

Solution: You can top off your vehicle with coolant to fix the problem. In some cases, you may need to patch up a leak if it is present.

HEATER CORE - Heater cores are very similar to radiators. They have coolant and fans to disperse heat. A common problem with heater cores are clogs, which can cause issues with your HVAC system. If your windows are foggy and your car smells sweet, check the heater core.

Solution: Flush out the heater core and manually clean it. Worse case scenario, you may have to replace the heater core altogether.

THERMOSTAT - The thermostat is responsible for reading the engine temperature and dictating whether coolant should be released into the engine or not. If it is faulty, it can block out coolant when your engine needs it. As a result, you will get cool air when the heat is on. 

Solution: Install a new thermostat.

HEATING CONTROLS - You’re probably familiar with the buttons, dials, or switches necessary to turn on the heat. If these are old and faulty, it can cause your A/C to stay on instead of switching over to heat. 

Solution: Replacing the controls or fixing the electrical problem that exists. 

If you need help stopping your car heater from blowing cold air, we invite you to bring your car to Central Park Garage today. We can pinpoint any heater problem and get you the necessary repairs.

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