Why is My Car Heater Blowing Cold Air?

December 13th, 2017 by

2018 Nissan Dash

When you climb into your car on a freezing day, the first thing you do is turn up the heater. But countless drivers have found themselves wondering, “Why is my car heater blowing cold air?” This inconvenience tends to result from problems with your coolant or blower motor, but it may be difficult to tell just what needs to be done without a visit to the shop. In this guide, we’ll go over some common problems with the car heater, so you can head into the service department informed and ready to go.

How Does a Heater Work?

Let’s start with the basics. While some cars have electric heaters or air-cooled engines, the vast majority of cars on the road today have water-cooled engines under the hood. These systems move warm coolant through a heater core, which is similar to a mini radiator. The blower motor moves air through the coolant, and the warmed air blows throughout the cabin. This process depends on the warmth of the engine, so it may take your heater a few minutes to get moving as your car warms up.

What Can Go Wrong?

There are several common reasons why your heater will blow cold air. Let’s break them down:

  • Your thermostat may be stuck, which can prevent the heater system from warming up sufficiently. If your heater is blowing lukewarm air rather than cold air, this may be the culprit.
  • Air bubbles may be trapped inside of the cooling system, which can cause malfunction. This air must be flushed out by a professional.
  • The heater core may be plugged by debris or corrosion, which prevents coolant from flowing. If so, the core must be flushed out or cleaned  by a professional.
  • The heater core inlet line may have a stuck valve. The car will not produce heat if this valve remains in the closed position.

How Do I Fix the Problem?

If you’re sick of a cold cabin, then stop by Tamaroff Nissan for a diagnosis and solution to your car woes. Our talented technicians can fix any issues with your heater, so you can enjoy cozier driving all winter long. Schedule your service today with our experts!