Tempremental Heater

[Jamo]

My heater has become tempremental. Sometimes it works fine, other times it just blows cold air.

Classic case was yesterday, cold air, stop to get some petrol blows out warm air after i drive off!

Any ideas folks?

[BRY]

Air lock in your system?

[Al@work]

Air lock in your system?
Bleed it with the car running and the heater on hot and full speed as yoda bry comments its most likely to be an air lock.

[Jamo]

I'll give that a bash, bleed from the rad screw?

[Greg_S]

Jamo,

When I had this problem it didnt turn out to be the matrix but the flap on the airbox that directs the air through the matrix.

For some reason it had jumped a couple of teeth so the flap never closed off to hot air. Got my head under the dash and tweaked it back into place and it works fine now

[rotoryboy]

I'll give that a bash, bleed from the rad screw?

Take res cap off, open bleed screw on rad and open Matrix hose valve (be careful with this one). When the air seems to have gone (no bubbles)close the rad then the matrix.

[dan_b]

As Mark says, you'll need also to try and bleed the little ******ing bleed valve on the matrix hose - it's a smallish pipe closer to the bulkhead. Be very careful with that little swine of a valve as the thread has a habit of stripping...