Webasto Valves
Finally took the time to figure out how my Webasto system works. This coach has three switches that cause the Webasto to fire off.
1) On the Marathon dash there is a switch call 'System Heat'. When this switch is pushed the Webasto fires and the small pump inside the Webasto circulates hot water through the two 10 gallon water heaters and now we have hot water.
2) There is a switch in the main electrical panel in the rear (bedroom) that says '12 Volt Water Heater'. Push that switch and the exact same thing happens as in #1. Interesting?
3) There is another switch in the main electrical panel in the rear (bedroom) that says '12 Volt Heat'. When this switch is pushed the Webasto fires and the small pump inside the Webasto circulates hot water through the two 10 gallon water heaters. Also, if any of the three heat exchangers in the coach that use the hot water for heat are calling for heat a solenoid valve opens and another aux pump in the spare tire area turns on which circulates hot water through all three of the interior heat exchangers. Now we can heat the inside of the coach. Nice!
That left me with only one more thing to figure out, how does the Webasto pre heat the engine. Well, after hunting all around I finally determined that in this coach the Webasto does NOT pre heat the engine. The Webasto system picks up and delivers coolant to the line that connects the coolant surge tank to the water pump (engine). By pure coincidence some of the heated coolant makes it down to the Water pump and warms it up. This was real informative beacause for the last year I believed the Webasto pre heated the engine.
All is not lost as the coach is equiped with a 120 volt block heater which works good. Mystery solved.
Below are a couple pictures of the three valves located at the Webasto unit. I'd like to confirm that these are just solenoid valves and not pumps?
Reply With Quote