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Water cooled heater issue

Posted: 21 Nov 2016, 08:51
by vwaddict
So, this is the 1st water cooled t25 I've had & my question is with the temp gauge in the middle after letting it get up to temperature, why is it that when I put the blower on the air comes out hot but within probably 10 to 20 seconds it goes stone cold?!??
Any suggestions why would be much appreciated.

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Re: Water cooled heater issue

Posted: 21 Nov 2016, 09:16
by itchyfeet
yours is converted from Aircooled so maybe its not plumbed in right, follow the pipes they should connect directly to the engine circuit and not the main radiatpr circuit.

Re: Water cooled heater issue

Posted: 21 Nov 2016, 11:04
by vwaddict
itchyfeet wrote:yours is converted from Aircooled so maybe its not plumbed in right, follow the pipes they should connect directly to the engine circuit and not the main radiatpr circuit.
It's a 89 bus with a jx in it......

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Re: Water cooled heater issue

Posted: 21 Nov 2016, 11:26
by kevtherev
We're going on your signature
Was this an Aircooled van originally?

Re: Water cooled heater issue

Posted: 21 Nov 2016, 15:38
by itchyfeet
vwaddict wrote:
itchyfeet wrote:yours is converted from Aircooled so maybe its not plumbed in right, follow the pipes they should connect directly to the engine circuit and not the main radiatpr circuit.
It's a 89 bus with a jx in it......

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best change your signature then.

still worth checking its plumbed right, air lock is the only other explanation I can think of

Re: Water cooled heater issue

Posted: 21 Nov 2016, 16:27
by kevtherev
Air or just a plain blocked matrix or kinked pipe
My heater does a similar thing, I suspect the matrix is sludged up after washing out the main rad it was pretty obvious.

Re: Water cooled heater issue

Posted: 21 Nov 2016, 17:21
by vwaddict
Apologies for the mis leading signature, that was my previous bus, I'll correct it.....
I also know that no heat comes from the rear blower under the seat....
The coolant does look very sludgy, I'll give it a flush & see what happens.

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Re: Water cooled heater issue

Posted: 21 Nov 2016, 17:34
by kevtherev
Has somebody been mixing antifreezes?

Re: Water cooled heater issue

Posted: 21 Nov 2016, 17:44
by itchyfeet
I take it the valve and slider are working?
A trickle of coolant would explain it, gets hot but won't sustain heat with fan on

Re: Water cooled heater issue

Posted: 21 Nov 2016, 23:33
by vwaddict
itchyfeet wrote:I take it the valve and slider are working?
A trickle of coolant would explain it, gets hot but won't sustain heat with fan on
I'll check that out.....

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Re: Water cooled heater issue

Posted: 26 Nov 2016, 16:37
by vwaddict
itchyfeet wrote:I take it the valve and slider are working?
A trickle of coolant would explain it, gets hot but won't sustain heat with fan on
Ok so, heater valve works fine checked that, flushed the system with no blockages, but the heater is still cold at the front.
The rear is warm now as the valve was in the off position.....
Could it be an air lock??

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Re: Water cooled heater issue

Posted: 27 Nov 2016, 08:51
by kevtherev
You can disconnect both pipes to the heater matrix from outside the dash near the engine bay, then perhaps you can get a hose on one end and force some water through.

Re: Water cooled heater issue

Posted: 27 Nov 2016, 10:18
by vwaddict
kevtherev wrote:You can disconnect both pipes to the heater matrix from outside the dash near the engine bay, then perhaps you can get a hose on one end and force some water through.
I done that yesterday to see if there was any blockages down those pipes.....
Im thinking maybe I need another go at bleeding it..



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Re: Water cooled heater issue

Posted: 27 Nov 2016, 15:59
by kevtherev
That's pretty conclusive then.
rev the teets offer it, till the bubbles stop