Heater not working in cold weather?

[ressull]

Hi, I've been searching around for ages for an answer but still no luck so thought I would start a thread.

The heater on my 2002 1.9TDi A4 doesn't work when the weather is really cold, then just starts to work after driving for a while. I have been advised to replace the fan brushes but after removing my fan heater motor I dont think it has brushes on it and the advice has been based on the B5 model. Does this sound correct?

I've also read that I should check the heater element for the coolant system but I'm not sure what I'm looking for exactly.

Does anyone have any other ideas? I'm guessing that the fan motor is ok as it seems to work when the temperature is okay.

I'm no mechanic, but dont mind having a go if it is something relatively easy and if it avoids a hefty garage bill then all the better.

Thanks,

Russell

 

[aragorn]

When you say it "doesnt work", do you mean no air comes out, or that the air comes out cold?

 

[ressull]

no air comes out at all. Sometimes it comes on for 1-2 seconds then shuts down again.

 

[23e Heure]

I had this issue too during the freeze, so interested to hear if it's an actual 'fault'.

For me if I put the heater on Auto it took 5 mins or so driving before it turned the fans on and started warming the car.
I could still manually get the fans running immediate after start if I switched Auto off, but there wasn't much heat being generated for a while.

I had assumed that in Auto mode the heating was waiting for sufficient warm up (from sub zero!) before bothering to blow air about the cabin? And therefore by design, and not a 'fault' at all

 

[ressull]

I'm not 100% sure but I think I tried it on manual and auto with no air coming through. I'm gonna fit the motor back in over the weekend and see how it goes. I'm thinking there is a fault as I've never had a car that the heater doesnt work in freezing weather, seems a bit odd.

I'l keep you posted how I get on. No doubt it will be fine untill the next freeze.

Thanks

 

[ressull]

as i guessed. Got up this morning and temperature was reading -1 and heater didnt work. came on after around 20mins which is a real pain as you cant demist the windows untill then. You hear the vent opening then works for a second then air stops coming through. Tried auto and manual and no difference.

 

[quattrojames]

Weird this.

Under what circumstances does it start to work? Is it because the air temp inside the car increases? Or do you drive the car and it's when the water temp increases to running temp?