My heater valve was leaking (heater not going off). I switched in and out heater hoses, that made it better but still some heat at the demister. Do I have to replace the valve or is there a fix? Just put up with the heat?
It's a common complaint on the S1/S2 style heater valves. Usually means that the sliding arm inside the capsule is not making a seal against the shell...which lets hot coolant leak through. Replacing the valve (if you can find one...last I checked, it was made of unobtainium new) is one way...or adapting a different arrangement.
Interested to hear of others' thoughts. (FWIW, the heater valve on my TC has to be wired shut during the non-winter months because it creeps open if I don't lock it in place...but that part is still available...so will replace when I do the head gasket...so creeping heat in a Europa is not an unknown occurrance...).
Maybe adapt something like this:
https://www.summitracing.com/parts/FSS-74764#overviewMay take some mechanical work, but...necessity is the mother of creativity...