Volkswagen Jetta Heater Not Working? Here’s Why

There are a few reasons why your Jetta’s heater might not be working and fortunately they aren’t all complicated to fix. The following is a list of the most common reasons it might have stopped and how you can fix them.

VW Jetta Heater

Buy factory VW Jetta parts online here.

Issue: The fans will only blow air on certain settings, not on others.

What to do:

This is a standard symptom of the blower motor resistor having failed. The part you’re looking for is behind the glove-box and isn’t too complicated to change. This video will give you a good guide for how to fix the problem on a 1999 – 2005 Jetta (4th Generation, Type 1J).

Issue: There is no heat coming out of the vents and the car isn’t getting up to temperature.

What to do:

If you have both of these symptoms then it’s quite likely that the problem will be with the thermostat, and in this case, it’s most likely that it’s stuck open. Replacing this should fix the problem, and although you can do this at home it can be quite difficult and will require some patience. This video will show you how to do this and you should watch it before you decide to do this yourself and you may need so additional tools before starting. If you’re not confident doing this yourself then take it to a specialist.

Issue: There is no heat coming out of the vents but the car is getting up to temperature.

What to do:

If you have this problem, or the problem persists after you have changed the thermostat in the car then it’s quite likely that there is a blockage or air in the heater core. The simple way to test for this is to bring the car up to running temperature and see if there is a dramatic difference in the temperature of the hoses coming out of the heater core. If one of them feels colder than the other then it’s quite likely there’s a blockage or air in the system.

Repairing this can be done at home with a little bit of creativity as shown in this video but if you aren’t confident in doing this yourself then you can take the car to a Volkswagen specialist to have it done.

Issue: Poor heating and/or foam parts coming out of the vents.

What to do:

This is a sign of wear on the blend door in the heating system. This can be a tricky job to repair yourself as it will involve you getting deep inside the dashboard, or in some cases, removing it completely. There are some guides online that show how to do this, but I would personally have a specialist look at this for you.

Issue: Smoke coming out of vents and/or a sweet smell to the air coming through.

What to do:

This will often be coupled with poor heating. If this is the case then it’s likely that the heater core in the car is damaged. This is a very time consuming job to replace as you will need to take off the dashboard and steering wheel and should only be done by a specialist or yourself if you are a confident mechanic.