Aux Heater Fault

[Lee S]

How do I do that? Do I just add Snap's adaption codes/values in and that's it? Sorry.. I'm a VCDS dunce...

[Mechcanico Lee]

I would say Snap D has more knowledge than me in this field , im really not sure which adaptation gets the rest pump working , hopefully he will be along at some point and give you a lift .

Keep at it mate is a great function , mine did a 30 min run this morning before i got in the car ...... it was lovely and toasty inside hehe

[snapdragon]

You know what - I am doubting what I said, because today it was timed to come on and the car was cold. The times when it was warmed up is when I went out before breakfast and without turning on ignition I held the on/off button on the HVAC controls until it came on, set both side to HI and locked up and went back inside. When I do this it is very warm 20 minutes later, but doesn't seem to be the case when on the timer - it comes on but seems to have little effect.
Not enough fuel to test now it is disabled when the low fuel warning is on.

[tc4332]

I use the "Set Up" button on the HVAC control.
Rotate the right hand knob to select "Aux Heater On" and the Webasto fires up.
Snap, I'll try your way on Sunday. I have an early start in the bus and nobody else will need the car.
When I use the timer the Webasto fires but does not "toasty" the car, but the engine and heater seems to do the warm up much quicker. But then that is what the Aux Heater is for, until you add the extra pump and plumbing.
Nothing to do with this thread/forum but I have a night heater under the bus and this operates on it's own timer but all it does is blow a small amount of warm air into the bus. It makes ice on the windows much softer that then clears with the wipers. Certainly takes the edge of the temperature. In a smaller vehicle/cab it would be good.

[Lee S]

Originally Posted by snapdragon

The times when it was warmed up is when I went out before breakfast and without turning on ignition I held the on/off button on the HVAC controls until it came on, set both side to HI and locked up and went back inside.

So this is using the "rest" pump and the aux heater then? How does that work yet the aux heater on the timer doesn't work? I don't understand. Or is it down to your extra adaptions Snap? I might try that now.... see what mine does. Surely it will just set the pipes gurgling again won't it?

[Mechcanico Lee]

Auxiliary Heater water pump is mounted to the Webasto unit so the water pump is right near where it needs to be efficient to get the water flow up to the heater matrix .

The rest pump is there to allow the heater to give warm air when the engine has been switched off , but it must be able to get some flow through the aux heater and stopping the water from boiling up ....just some flow will be enough to stop the water from boiling and getting the flow into the heater matrix core

[Lee S]

Interesting. So do I need the aux heater set to on or will it come on on its own when I turn the hvac on via the on off button? This could be a reasonable solution by the sound of it. Will have a play in the morning. And this works on a cold car with the ignition off?