You actually have 3 heaters on your van.
Heater 1 is the standard vehicle heater that gets warm when the engine warms up. Comes with air con on the Cali.
Heater 2 is the Eberspächer Airtronic heater (or parking heater) that is controlled from the centre consul and runs off diesel from the fuel tank. It ticks. Blows out hot air just behind the drivers seat at the bottom of the B pillar.
Heater 3 is the Webasco Thermo Top C coolant heater just for the engine. The onboard computer will fire this up when the outside temp is below 5ºC and warms the engine coolant water up quickly. This also runs off diesel and the pump ticks too. Often you see or smell diesel fumes from behind the front N/S wheel when this is working. Doesn't run for long though.
Alan
If we go that way ....what about heated seats as the 4th heater?
It is a good point to turn the normal heater in the dash full power few minutes before arrival at site on a cold day ...
Wow, never knew about the Webasco
The Webasto coolant heater was/is available with an optional upgrade to allow it to be used to preheat the engine and cabin. According to the VW manual, that’s the remote in the picture posted by @Bigted in a related post.The webasto is the auxiliary engine coolant heater that kicks in below 5 degrees to heat the engine circuit quicker and reduces emissions on warm up in cold weather. That is automatic. The eberspacher is the air heater that you control when camping. They don't all come with a remote control as it was an optional extra.
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