Why isn’t my car’s heater working?

Now that we’ve had a few chilly mornings, you might have noticed that your defroster isn’t quite working properly or the air coming from your vents is a little cooler than you remembered… This may be due to a problem with your car’s heating system.

There are a number of reasons why the heater in your vehicle might not be working properly. Here are the most common ones:

Low Coolant

A car’s heating system is super simple. As the coolant circulates through the engine, it absorbs heat, and funnels through a much small radiator called the heater core. Instead of venting the heat outside the car, like it would if the heater was not running, a blower fan pushes the warm air from the heater core, through the car’s air ducts, and into the vehicle’s cabin.

If that coolant is running low, you have a big problem. There’s likely a leak that’s causing the fluid to evaporate on its own or became contaminated– which wouldn’t normally happen to a well-functioning system.

Blown Fuse

The main job of a fuse is to protect the electrical system in your engine from shorting or overloading, which can cause them to burn out or even catching fire. These tiny safety features will blow or open when the electrical current in the system exceeds their design rating. If a device draws enough current to blow a fuse, you’ve probably got a problem somewhere else in the system that will cause the fuse to blow again, sooner or later. Rarely do fuses fail for no apparent reason.

Air Pockets

Air pockets can prevent coolant from properly flowing through the heater core. The mechanic will flush out the air pockets from the cooling system according to the manufacturer’s instructions and perform a pressure test to determine where the air is entering the system. Typically, the air can be traced to a small, early leak that’s allowing coolant to escape sucking in air to take its place.

Old Thermostat

The thermostat regulates the flow of coolant to help the engine warm-up. While the engine is “cold,” the thermostat doesn’t allow coolant to flow through the engine. Once the engine reaches its operating temperature, the thermostat opens and allows coolant to start flowing. If the thermostat wears out, it can remain stuck in the open or shut position, causing the engine to either overheat or cool operation, respectively.

Malfunctioning Blower Motor

Fans can go bad for all kinds of reasons but, thankfully, getting a replacement is fairly painless. Before they install the new part your mechanic will also check the resistor, motor, and fuse to make sure they’re not contributing to the fain failure. It adds a few extra bucks to the final bill but you won’t end up back in the shop with the same symptoms.

At V&F

No one likes to drive while shivering but a broken heater can also hinder your visibility and limit your ability to drive safely. At V&F, we strive to provide our customer a well-rounded knowledge of all things automotive. Since 1988, our family-owned and operated service center has been providing top-quality auto repair services to Agawam, Feeding Hills, Southwick, West Springfield and the surrounding Massachusetts communities. If your car needs maintenance or repair before this winter season, call us at (413)314-2280 or schedule an appointment online.

Written by Nicole Palange

Leave a Reply

Your email address will not be published. Required fields are marked *