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A Few Questions You May Have About Your Car Heater

car a/cIn the desert, contrary to popular belief, we do have chilly evenings and cooler mornings. Even if we use it just a few times during the winter and early spring seasons, having a heater in the car is essential to staying warm behind the wheel. At Sun Devil Auto, we’re constantly answering questions about the air conditioner in the summer and it’s only fair to share a few of our frequently asked questions about the heater. The answer to our most commonly asked question, “Does car heater consume fuel?” may even surprise you.

Q: How Does the Heater Work?

A: When the engine is running, it creates heat. Usually, this heat is dispersed to the outside air through the radiator and coolant. The water pump pushes the coolant through the cooling system, including the heater core. The evaporator housing, located behind the dashboard has a blend door, which determines whether the air goes through the heater core or through the air conditioning evaporator. The air going through the heater core becomes hot air to heat up the passenger area of the vehicle.

Q: Why Does It Take Time to Heat Up? What’s a Normal Wait Time?

A: It takes a while for the coolant to get to the proper temperature before the heater core can produce enough heat. Since the heater pulls heat from the engine, it takes time for the engine to warm up. The cooling system thermostat restricts the flow of coolant to allow the vehicle to warm up faster. Wait times can vary based on the outdoor temperature. For example, a cold winter morning in Arizona would be faster to heat up than a mid-winter startup in Alaska.

Q: Does Car Heater Use Battery?

A: The heater itself will not drain the battery, however, the fans that blow the heat may. Heater fans get power through the accessories connection of the ignition switch. If the car is off, it will not receive any power. If the fan was left on without the engine running, where the key is in the accessory position, it could drain the battery in as little as a half an hour!

Q: How Does Car Heater Work Differently than the A/C?

A: The air conditioning system works with many components including the compressor, condenser, receiver-drier, refrigerant, and other vital components. Outside air relies on each of these pieces to create and provide the cold air. On the other hand, the heater uses the heat from the engine’s hot coolant.

Q: Does Car Heater Use Gas?

A: Yes, but indirectly. Gas is required to run the engine which produces heat. Using the heater does not affect fuel efficiency as opposed to the air conditioner, as the heated outdoor air is simply being redirected and moved into the cabin.

Q: Why Is My Car Heater Not Getting Warm?

A: There are a few reasons why the heater may not be working. Symptoms may include a burning smell or blowing of cold air. Most often though, it’s caused by one of three problems: either the vehicle is low on coolant, the heater core is plugged, or there’s a problem with the thermostat. If the vehicle is low on coolant, the heater may produce semi-warm air or only cool air as the air is unable to be heated properly. Likewise, if the heater core is plugged the coolant can’t pass through, and if the thermostat is malfunctioning, heat is unable to be generated. The thermostat’s job is to restrict coolant flow based on the engine’s temperature. If the thermostat is stuck in the open position, the engine’s operating temperature may not reach the correct level to blow warm air.

Q: What Are Some Other Reasons My Heater Is Not Working?

A: Because there are several passages that the air must go through to heat up before reaching the passenger area, there are a few components that may be the cause of heater complications:

  1. The heater core may be clogged from the viscous coolant, similar to a clogged radiator.
  2. When air comes into the dashboard it must pass through the temperature blend door. This door moves to change the temperature of the air coming in by blending just enough warm air with cool. If the blend door actuator fails, the air output will default to hot air only, preventing it from blending with cool air.
  3. To push the air through the heater core the blower motor must be operational. If it fails, the amount of air being pushed through decreases dramatically.

At Sun Devil Auto, we take pride in our knowledge of all kinds of makes and models of vehicles. We have the answers to all your questions when it comes to your heater, air conditioning, transmission, and everything in between. Our friendly Service Consultants and Technicians can educate you on what your vehicle needs based on mileage, age, and condition. We have an A+ rating with the BBB and have been in the automotive business in the Phoenix area for over forty years. When you’re looking for dealership quality repair or maintenance and unmatched customer service at a competitive price, you’ll find it all and more with Sun Devil Auto.