Car Heater Blowing Cold? What Could Be Going Wrong


When a car heater is working correctly, it will provide an ample amount of warmth for the occupants within. Indeed, the driver will need to regulate the controls, or the passenger compartment will become unbearable. Yet now and again, something will go wrong, and that much-anticipated heat will fail to arrive. In this case, what could be getting in the way, and what's the remedy?

How It All Works

Most vehicles rely on a hot water system to regulate conditions inside the passenger cab. The internal combustion engine will heat the water, and it will be diverted to the internal heater by a small device known as a thermostat. This thermostat sits at a crucial junction and will divert hot water towards the heater matrix as and when required. It will open or close according to a given temperature reading, and if it were to fail, all that hot water would be sent through to the cooling system instead.

Thermostat Malfunction

The first thing to do is to check the efficiency of the thermostat, as it may be stuck in the open position and may prevent the engine from warming up as quickly as it should. You may eventually get some lukewarm air instead until you change the thermostat.

Heater Core

Alternatively, you may have an issue with the mini radiator that sits in between the bulkhead and the dashboard. The system is supposed to push that hot water through this matrix, and a blower fan is then supposed to force air across the surface and into the passenger compartment. Sometimes, air can get into the cooling system, and this may become lodged within the matrix. When it does so, you will need to flush out any air bubbles before normal service can be resumed.

The heater core is also vulnerable to corrosion, and when this happens, contamination can build up and clog those tiny internal tubes. In this case, the heater core will have to be flushed out entirely or, in a bad situation, may need to be replaced.

Action Needed

If you're not sure how to proceed, then this is a job for a qualified mechanic. When you take the vehicle to an auto heating repair shop, they will check the efficiency of the thermostat and will have a closer look at the heater core. If they need to flush the system through, then they have the right tools for the job or can replace it as needed.


10 January 2020

Keeping Your Car in Good Condition

Cars are wonderful things. Unfortunately, they also have lots of technology and moving parts which can go wrong if they are not properly cared for. We hope that this blog will give you all of the info you need to service your car. We will be looking at subjects such as how to change the oil in an engine, how to replace a worn brake pad, and how to check the electrical systems on your vehicle. Everything you read on this page has been written by keen amateurs who have a really big passion for servicing their autos. We hope you love what you find here.