Caught the Webasto "short cycling" and figured the circulating pump had gone bad. Sure enough that was the problem, but the next issue was where to get the pump since Webasto won't sell to an individual, Prevost doesnt stock the part, the local dealer didn't want any part of trying to help out and the folks at the old standby - Vehicle Systems / AquaHot out of Colorado, have gone totally mental.
In fact a call to them got a quote of more than $950 for the pump. But the Prevost parts guru, Ron Beverly, came up with Bus Services of Sharon Springs, KS who actually had a Webasto guru named John who had the part for $481 and overnighted it as well.
Their number is 888-287-3499.