Archived Message
Heater blowing cold when at hot
Some advice needed. I've recently needed to switch on the hot air on but the heater is not very responsive. The dial is cranked up to max but at best it is a very modest heat and wondered what obvious checks I should do. Concerned that in colder weather it just won't be enought to get rid of any ice on the screen especially up here in Scotland! Many thanks,
Stephen Aitken
19/09/2012 @  14:22
Under topic: RV8
Archived Reply(ies) received for this Message
Heater blowing cold when at hot
I think the first check I would make is get a friend to sit in the car and turn the heater knob on and off whilst you open the bonnet and check whether the heater control valve is actually opening and that it is opening fully. The usual problem with these valves is that as they age they do not fully close, so in warm weather your feet get toasted.
Alan Rennie
19/09/2012 @  15:47
Heater blowing cold when at hot
This thread appears often, Stephen and there is certainly a workshop note on it. As Alan has already mentioned, there is a heater control valve sitting in the middle of your engine right at the back partly hidden. The valve itself can become very, very stiff and so the cabling then moves so that the valve does not open and close fully. As Alan suggests, note its position when the dash knob is at off and then turn the knob fully on and note the position again. It is easy to remove and you can then check for freeness and tighten up the cable clipping as appropriate.
Peter Garton
20/09/2012 @  05:58
Heater blowing cold when at hot
If the other solutions do not produce the required result, try to flush the system and see if water passes throgh the heater. When replacing all the hoses on my GTV8, I found the hot water valve was completely blocked by sludge so no water was pasing through the heater matrix.
Chris Yates
22/09/2012 @  10:36
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