Why Is My Car Heater Blowing Cold Air?

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You step out of your warm house and the chilly morning air instantly hits you. You rush to your car, turn over the engine, crank up the heat, and wait. Minutes go by, but only cold air keeps pushing through your heat ducts. What's the big idea?

At Nissan of Mobile, our experienced team of service professionals have been helping drivers throughout Mobile, Prichard, and Saraland with this issue for years. To further help our customers, we created this helpful guide to lay out some the common causes of this inconvenient occurrence. If you recently asked, "why is my car heater blowing cold air?" then continue reading to learn the answer.

Reasons Your Car Heater Is Blowing Cold Air

There are multiple reasons why your car's heater is blowing chilly air:

  • Heater core issues
  • Broken heater valve
  • Busted thermostat
  • Leaking water

Our team goes into more detail about each of these issues below to help you determine which one could be the possible cause of your heater not working. Keep reading!

Reason #1: Heater Core Issues

The heater core is located behind your vehicle's dashboard and is made up of brass or aluminum piping that heats up by using hot coolant (what an oxymoron). A fan then blows across this heated piping and into your cabin.

If you notice no hot air coming out, the first step is to check your coolant levels. This is the same coolant that's used to work your AC during the summer that gets transferred to the heater core. When your car is low on coolant, it won't be able to create enough warm air.

If your coolant levels are normal, then you might have an issue with the heater core itself. Some common symptoms include: a sweet-smelling odor from the heating ducts, foggy windows, or an overheated engine.

Reason #2: Broken Heater Valve

If you've owned your vehicle for a long period of time, the control buttons on your dashboard wear down or break at times, thus stopping you from opening your heater control valve. This valve is located inside your vehicle and is what reroutes heat into your cabin. This valve can also break or become clogged, keeping you in a permanent chill.

Reason #3: Busted Thermostat

On your dashboard, you'll notice there's a gauge next to your gas and speedometer with the letters "C" and "H". This gauge is your vehicle's thermostat and measures the temperature inside your engine system. If this is broken, it won't transmit the message to the heater core that the engine is warm and ready to blow hot air into the cabin.

Reason #4: Leaking Water

If your vehicle is leaking water, it can cause your heater core to underperform. Some typical areas to have inspected for water leaks include the radiator, water pump, and the hoses inside your engine system. You should also make it a point to have a technician inspect your coolant reservoir for any cracks or signs of other damage.

Get Your Vehicle Prepared for Winter!

If you recently found yourself asking, "why is my car heater blowing cold air?" we hope this gives you some insight on how to fix this common issue. If you're a driver near Mobile, Prichard, and Saraland currently stuck out in the cold, stop by Nissan of Mobile or go online to schedule a service appointment today!

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