Greg, Are your SMX pads push button newer type, or rotary knob?
In our coach, after we flip the 2switches on webasto unit, we then flip the "heat" switch inside the ccoach on a panel, in our case we have 3 switches, one at the entry door, one in kitchen, one in bedroom. One of these needs to switched on in order for webasto pumps to coome on independently from the engine producing hot watr and the engine water pump circulating coolant thru the exchangers. Otherwise, everything operates as you describe with exchangers heating only while engine is running
Our SMX pads only control the airconditioning, with rotating knobs.
Jim and Chris
2001 Featherlite Vogue XLV 2 slide with Rivets-current coach, 1999 shell
Previous 22 years,
We have owned every kind of Prevost shell but an H3-40