Webasto Question (I think)

I drove some 400 miles today and much to my surprise, the hot water tank, for some reason, didn't get heated as usual. Usually, after a days drive, the hot water would be very hot.... enough so to last a couple of days without needing the electric heater element turned on.

A couple of months ago, the engine coolant was drained and replaced, and an effort was made to isolate the webasto plumbing circuit at that time, so I'm guessing that enters into the mix.

So, what am I missing here? What should I be looking for as far as the valves are concerned?

Paul, my liberty, with a few more whiskers than yours has two gates valves, one each side of your engine. In addition, depends on design, has a least one gate valve that is hidden next to the radiator (its a good reach inside), left side of radiator, through a rubber covered access. These valves should be open for the complete coolant circulation. Also, check to see if there is a quarter turn valve on your inlet line coming from the engine into your hot water tank.

Maybe I am missing something but it surprises me that these valves are closed if they serviced / flushed your coolant system. On my coach, the wabasto and engine / hot water tank flow through lines are on the same system.

Thanks. I'll keep hunting for any closed valves.