I am having heater issues when I start my car I.

ANONYMOUS

MEMBER
1983 MERCEDES BENZ 300TD
150,000 MILES

I am having heater issues when I start my car I either get great heat or luke warm heat if I change the tempature control to cold or hot it doesn't make a difference it still put out really good heat or luke warm heat is it in my push button control unit or maybe the heater control valve can anyone please help.

1 Reply

BLAZE45

MECHANIC
380 POSTS

There are usually 2 reasons why people dont get heat in their car. The first is the blend door. This door allows you to switch from hot to cold air when needed. Sometimes the motor that actuates this blend door goes out and the door gets stuck or will not move properly. Sometimes they are cable operated and the cable breaks.

The other reason is a heat valve located on the firewall of your car. There will be 2 hoses going into the firewall on the passenger side. These let in hot water through your heater core. There should be a valve that actuates the hot water going into the car in the engine bay, or just on the other side of the firewall inside the car where the hoses go in. I would check this valve out first as a blend door is a bit more complex to repair.

You should be able to manually move the valve and see if you get heat!

Good luck.