Slightly warm air from heater on cold setting

[Cruz]

Sorry for not searching but I'm using a smartphone as I've no broadband at the moment and it's driving me potty.

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Probably answering my own question here but did I once read somewhere that warm air when heater lever is set to cold is caused by the heater valve not closing properly?

When the heater control is fully over to cold the air through the vents is slightly warm. I know it's summer but its never exactly cold on cool days. I have been under the van and the cable is free and moves the valve arm fully in both directions so I assume it's the valve that's on it's way out?

Am I correct in assuming the internal workings of the valve degrade over time and don't fully close off the hot water supply, gradually get worse then fail completely?

Ta

[kevtherev]

It's the only way the matrix gets coolant, via the valve.
So I guess whatever you say.. it's worn or not closing
I think I have a spare here.

[Cruz]

Any tips for changing it without losing enough coolant to have to bleed?

[1664]

Any tips for changing it without losing enough coolant to have to bleed?

Close old valve and close new valve. Remove old valve from heater control cable so it's hanging free.
Pull one end of pipe off old valve and immediately push onto new valve. Both valves should prevent water flowing out (even the worn one as the water is not under pressure). Then swap remaining pipe over.
You do lose a little water during swap over but a finger over the end of the pipe the moment it's removed keeps it to a minimum, I lost very little and when I say very little I mean certainly not enough to warrent a coolant bleed, and even so the water system should cope with some loss as there is the old header tank for exactly that (I think).

[kevtherev]

Hey! that's what I was going to say

[1664]

Hey! that's what I was going to say

Well you can do it next time

[ninja.turtle007]

I have the same issue. Can these valves be bought new?

E D I T: yes, £7.99.

[Cruz]

£7.99 valve snapped

New one bought from VW direct. Doing the swap tomorrow (saturday)

its nice how vw put the valve in such a tight place :/

[tensilekid]

hi is the cable outer clipped in the correct position (its held by a clip under the dash) so when lever is fully "cool" it moves the valve to fully closed. moving mine 10mm cured this on my van

[Cruz]

It was, it is, its been replaced with a new working valve