Hi!
The van I’m looking has a webasto engine heater. I’m wondering if it would be possible to remove it from the engine bay and use it as a water-based floor heating unit?
It means I don’t have to spend 500+$ on a diesel heater and I really prefer heated floors.
I assume it heats coolant/antifreeze and circulates it though the engine cooling system? Burns diesel? If so, just leave it where it is, cap the hoses in and out of the engine, and run new lines from it under the floor. You may have to add a reservoir to be sure the lines stay filled, and provide a place to add the 50/50 antifreeze. Could also simply tap into the lines going into the engine. That way your engine gets the benefit too. Probably a reason it’s there for the engine.
You can use it for the engine and the floor (and hot water, and forced air) if you want to. Even isolate each part with valves if you want, too.
If you’re talking about the OEM Mercedes one for a Sprinter, I would try to sell it and buy a Espar/Webasto/Planar instead of trying to figure out how to control the OEM one. If that’s the one you are talking about, it’s under the floor right by the driver’s door, not in the engine bay actually.
There’s tons of different ways to set it up. You can use engine coolant as the main fluid, or an exchanger so engine coolant is isolated to the engine bay.