Aux heater drains main battery?

[bmassaer]

After disconnecting the main battery for a job, I noted that the auxillary heater did not funcion anymore (with message "not connected". So it seams that this heater is connected to this main battery. Would it drain the battery if used for a longer period?

 

[calikev]

The aux heater runs of the leisure batteries not the van battery

 

[WelshGas]

What vehicle.?
As far as I am aware on a California SE the auxiliary diesel heater is powered by the leisure battery but the circuit that controls it maybe powered from the main vehicle battery and hence why you have this error. The control unit has lost sync with the heater unit. Maybe, but someone will be along shortly who can confirm this or not as the case may be.

 

[bmassaer]

It's a 2007 Cali - indeed, the message was something like "not connected"...

 

[WelshGas]

Might be something in the Control Panel secret menu.
Press the Escape button, bottom R, and press the Control Button simultaneously. Scroll down menu and check.