How to Make Sure Your Car Heater Works in the Bleak Midwinter

Posted on: 18 September 2018

It is said that people who live in subtropical climates suffer from a "thinner" blood, which makes them particularly susceptible to any colder weather. Whether this is just an old wives' tale or not, the fact remains that winter time can get quite chilly in certain parts of the continent. As you may remember this sensation from last year, you will need to make sure that your vehicle comes to your defence when the mercury dips, and make sure that the heater springs into action. To survive this frigid onslaught, what do you need to do?

How Your Heater Works

Ultimately, your cabin heating system relies on the primary radiator seated at the front of the vehicle. This is somewhat ironic, as the main purpose of this component is, of course, to cool down the water flowing around the engine. This clever system works by diverting some of the hot engine water to a secondary radiator that is situated in between the engine compartment and the cabin. A simple thermostat will open strategically to let hot water flow to the second radiator, and a stand-alone fan will then blow the heat created through the air ducts, to help you warm your toes.

Faulty Parts

If everything is not as it should be, then you need to look at the thermostat. In older cars, this is a purely mechanical device, but in modern-day vehicles, it can be controlled through a sensor linked to the ECU. Occasionally, the thermostat can become stuck in the open or closed position, and this will affect how much hot water can be used to heat the cabin.


The cooling system relies on a special antifreeze solution, and over time, this can degrade to a certain extent and leave sediments within the pipes. Also, tiny particles of rubber can wear away from the inside of these pipes, and this residue can block the secondary radiator with detrimental effect.


If you want to restore functionality, you may need to flush out the entire cooling system, including both radiators and all the pipes. This may need to be done several times to bring everything back to normal, and it's best if you use compressed air as part of this solution. Be careful, however, as if it's not done properly, it can cause damage to the system and be counter-productive.

Best Course of Action

To be completely sure that your vehicle is ready for the arrival of winter, take it into your local car service. They can renew the thermostat if needed and make sure that all the pipes are clear of any deposits.