Water cooled heater issue

[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.

Sent from my E6853 using Tapatalk

[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.

[vwaddict]

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......

Sent from my E6853 using Tapatalk

[kevtherev]

We're going on your signature
Was this an Aircooled van originally?

[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.

It's a 89 bus with a jx in it......

Sent from my E6853 using Tapatalk

best change your signature then.

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

[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.

[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.

Sent from my E6853 using Tapatalk

[kevtherev]

Has somebody been mixing antifreezes?

[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

[vwaddict]

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.....

Sent from my E6853 using Tapatalk

[vwaddict]

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??

Sent from my E6853 using Tapatalk

[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.

[vwaddict]

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..



Sent from my E6853 using Tapatalk

[kevtherev]

That's pretty conclusive then.
rev the teets offer it, till the bubbles stop