Heating

Hi there,
Just wondering if anyone knows much about the heaters in the mk1?
Mine seems to constantly heat up massively even when the blowers are not switched on. It dies not blow any cool air and is constantly heating everything behind the dash. It gets so hot that the stereo is almost cooking!

I was going to strip the dash down to have a good look but just wondered if anyone had any ideas before I did so.

the heaters are controlled by a valve in the engine bay, you can see it inline with one of the pipes going to the bulkhead. have someone fiddle with the heater knob while you watch the valve and control cable

Cheers for that. I'll have a fiddle with it and see if it's seized or anything..
If it saves me stripping the whole dash down then it'll make life a lot easier..
Cheers!