Skip the auto shop - Our mechanics make house calls

How a Car's Heating System Works

heater how it works

The sun sets, and the air has a chill. You pause to flip your jacket collar up, and you walk briskly to your car door and slide into the driver's seat. Once you start your car, it’s only moments before the fingers you’re holding in front of the vent begin to feel some heat. The tightness of near-shivering muscles starts to relax as you shift into drive and start for home.

Your car’s heating system integrates another system’s functions to keep you warm. It’s closely related to the engine cooling system and shares some of the same parts. Several components are at work to transfer heat into the passenger compartment of your vehicle. They include:

  • Antifreeze
  • Heater Core
  • Heating, Ventilation, and Air Conditioning (HVAC) Control
  • Blower Motor
  • Thermostat
  • Water Pump

How Your Car’s Heater Works

First and foremost, your car’s engine need to run to warm up the engine’s "antifreeze." The antifreeze is what carries heat from the engine into the passenger compartment. The engine will need to run for several minutes to build up heat.

Once the engine has reached operating temperature, the "thermostat" on the engine opens and allows antifreeze to flow through. Commonly, the thermostat opens at 165 to 195 degrees. As coolant begins to flow through the engine, heat from the engine is absorbed into the antifreeze and carried through to the heater core.

The "heater core" is a heat exchanger much like a radiator. It is mounted inside the heater housing inside your car’s dash. The blower motor pulls air through the heater core, removing heat from the antifreeze circulating through it. The antifreeze then carries on to the water pump.

The "HVAC control" inside your car is integral to the your heating system. It allows you to create a comfortable environment by controlling the blower motor’s speed, the amount of heat in your car, and the direction of air movement. There are several actuators and electrical motors that control doors inside the heater box in your dash. The HVAC control communicates with them to change the air direction and the temperature regulation.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...


Related questions

Q: My car overheats and I have no heat - 2004 impala.

Hi there. Check the radiator and see if its plugged up. A plugged radiator will stop the flow of the coolant to and from the engine and cause the engine to overheat. If the radiator is working fine by having...

Q: Crack in coolant reservoir

Hello! That is a common issue with Audi Quattro models. The plastic tank holds the pressure of the coolant system. The reservoir is located right above the engine. Of course the engine gets hot and hot air rises so the...

Q: Air conditioning not working

A non working air conditioner is a concern for me, especially in a bigger vehicle like your Tahoe where it can get pretty hot. I see here that you noticed that the A/C condenser clutch is not operating and that...