I need help or advice from someone with good knowledge of a heating matrix.

**Kev Stephenson** · 02-05-2015,07:03 PM

First of all I'm new to this forum so it's taking a lot to get used to! Sorry to the admin if this is the wrong place to ask this question.
I've bought a 2000 model mk4 golf gt tdi! I think I've had my pants pulled down. I've changed my thermostat and still can't get heat. Bottom hose is cold! I know it's the matrix Ive got a feeling! Any advice from anyone to tackle the problem apart from taking the dash out and replacing it. Any tips will be much appreciated 👍😦

**zollaf** · 02-05-2015,07:18 PM

have you checked the water pump is actually pumping. is there flow through the little pipe at the top of the resevoir ?

**Kev Stephenson** · 02-05-2015,07:25 PM

Yes mate the water is flowing back nicely. I've also checked for an air lock! It's not that. I've tried removing the new thermostat and bypass for heat. But nothing! When I did that the bottom pipe did warm up. I put the new thermostat back in and still no joy

**zollaf** · 02-05-2015,07:28 PM

so you get no hot air at all from the matrix. have you checked the heat control flap that gives you hot or cold air ?

**zollaf** · 02-05-2015,07:30 PM

and why are you expecting the bottom hose to be hot. its a diesel that has enough trouble getting to running temp anyway. a cold bottom hose means the stat is staying closed which it normally will be just letting a bit of water into the top of the rad which is quickly cooled.

**Kev Stephenson** · 02-05-2015,07:36 PM

Yes mate its in working order. If I turn the heating to red for heat and leave the fan on zero it heats up a little. But if I turn it up to 2 3 or 4 it blows luke warm and doesn't heat the way it should! I've bled the system and still no further forward.

**Kev Stephenson** · 02-05-2015,07:38 PM

Ok I'm new to a diesel engine so the bottom hose to be cold is normal?

**Kev Stephenson** · 02-05-2015,07:55 PM

So the bottom cold pipe is irrelevant. OK. It has to be the matrix then?

**Kev Stephenson** · 02-05-2015,09:53 PM

Well I'm going to flush the inlet and outlet to the matrix. With a garden Hose. Maybe add some industrial degreaser that gets used at work on floor cleaners! It maybe a good idea or not. But I'll let you know how I get on.