When the engine reaches running temperature the heater stops working. The Haynes manual is as usual worse than useless. The thermostat opens to allow water to pass through the radiator and closes anther port and stops flow to the heater. Has anyone got a circuit of the heating system perhaps someone has plumbed it incorrectly. Help!
VW had a recall on a heater bypass valve. If this is still in your Golf then you need to remove it and re-connect the two rubber pipes back together with a copper pipe. The overflow pipe can be blocked off with a bolt. See the url link for the step by step process. Hope it helps you.
Regards
Vdubs
Vdubs
December 2004
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