Lukewarm Response From Golf Mk2 Heater

[garfayliu]

Hello

I recently resolved my problem of no heating in my mk2 F reg.

I simply replaced the bypass valve going to the heater matrix with two 22mm diameter copper pipes, around 15cm long. (Pick up some off cuts for free)

I figure loads of mk2's were made before the recall for the bypass valves and I'm sure most were fine. Only reason for the valve is to prevent pressure build up in heater matrix.

As I said, works fine, nice and warm inside car now, ready for winter

[markzwei]

For the last couple of winters, the heater on my Mk2 Golf 1.8GL has been only able to blow out lukewarm air, at best, although having tried the heater a couple of times throughout the summer it appears to be operating normally (hot) which, of course, is of little use.

I fitted a replacement Halfords thermostat about 18 months ago but this appeared to have no effect on the operation of the heater.

Any suggestions regarding the possible cause and remedies to the above would be greatly appreciated.