Webasto Question (I think)

[phorner]

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?

[Jon Wehrenberg]

Without looking to see if your Webasto is set up like mine this is just a guess.

Look in the Webasto area. You should see several valves which Liberty has marked. Depending on how they are set (open or closed) the coolant flow to the house loop could be shut off and coolant is only circulating in the engine loop.

I drew the system coolant circuits, and I think Mango posted them on his prevoman web site. It shows the circulation depending on which valves are open or closed.

That would be where I would start looking.

[phorner]

I'll look for that diagram.

I'm also running the webasto to see if it heats the water tank. It will at least give me another piece of the puzzle.

All of the valves in the webasto area, with the exception of the one labeled "Webasto bypass" appear to be in the open position.

Thanks for the helping hand...

[MangoMike]

The diagram is not on Prevoman, but I do have it somewhere and I'll see if I can find it tomorrow.


Mike

[phorner]

Thanks, Mike.

Still enjoyed perusing the Prevoman site again though....

[GDeen]

Mike, did you do all the work on your Liberty Webasto or the one in your Marathon? Mine wouldn't light in Yellowstone so I need to figure that out. Based on some of the posts here and your Prevoman info, it could be a number of things. So, if you diagramed the Marathon system that would be of great help also. (still getting hot water when driving, but the heater side won't fire)

Thanks!

[garyde]

I was told by Troy at Liberty to just open the Water Heater loop valve only about half way or the coolant would not circulate.

[Ray Davis]

Gordon,

I think it's fair to say that the Marathon and Liberty plumbing for Webasto are quite different. If your coach is like mine, there are two solenoid controlled valves in the webasto bay (left engine side). I had issues with this, and remove the value innards on mine. A stuck valve was causing no end of problems.

What is your problem with it lighting? Does it light at all? Not stay lit? Do you hear it trying to light? You would hear the spark in that case.

Generally it's a pretty simple system to track down. Let us know more about how you're failing.

Ray

[Jon Wehrenberg]

Apples and oranges, Ray. Paul does not have hot coolant from the engine circulating through the hot water heater loop, something that happens when the engine is warmed up so he gets hot water just from driving.

On a Liberty we have three ways to warm up the water in the HW heater. We can go for a drive. Engine coolant circulates through it and heats up the water. We can plug into shore power and turn on the HW heater switch in our electrical panel and an electric heater will heat the water, or we can turn on the Webasto, and as the Webasto is warming the coach, it is also heating the water in the HW tank.

Paul's issue sounds like some valves that need to be opened to allow coolant to circulate are not opened and the engine coolant is not circulating through the HW tank heat exchanger.

Paul, Did you check the coolant valves at the HW heater? Those may have been closed.

[dalej]

Paul,

If you haven't had engine heated water since the service then I would suspect that you a vapor lock.

I would try running the Wabasto and the engine up to temperature at the same time and look for the bleed off valves. I have three or four on mine. Bleed the lines until you have anti-freeze coming out.

It's a pain, but has to be done.

If you can isolate the circuit, sometimes the water will push the air out to the radiator.

Good luck!