Help For a friend on an aqua hot

[lbriant]

My buddy has a Winnibego and his Aqua hot will not fire off the diesel burner unless the water is already hot his electric element works but he has to start his coach and run it sometimes 1/2 hour before his aqua hot will fire off then he can shut the coach off and it will cycle and run fine for days ??
It was doing it last winter and he called winnabego and they said that is how it is suppose to work I told him that is insane ?? so he finally called aqua hot and they told him no something was wrong that the diesel burner is always your first heat source they were going to e mail him some info, any way no e mail so That kind have stumped me I could only think of possibly a bad sensor or if his fluid was just a shade low because the only thing you are changing by starting the coach is warming up the water and expanding it a little ?
I Jokingly told him to Jack the radiator cap up and drive a Prevost under it :cool:
But i told him I would run it threw the think tank here at POG .
So any Ideas would be appreciated his coach is a 2011 I belive,

[lbriant]

Wow no replies really ??
I thought between all our brains we could solve anything !!!

[dale farley]

Larry, That sounds like a tough one that I've never heard anyone else have such symptoms. Maybe someone will come up with a suggestion.

[garyde]

It may be a sensor which believes the temp is OK. It may have an in line temp sensor which is not reading correctly> On the Webast, you can take the igniter out and test it to verify its sparking, similar to a spark plug.

[Joe Camper]

I think your idea fits the scenario but Im sure U already checked that. Is there a low level sensor that would prevent ignition? Didn't know that either.

Possibly a wire end terminal is loose a bit and heat makes the contact better. Id do a wiggle test on everything I could get to.

Larry I think U R going to teach us something let us know the fix when U get there.

[lbriant]

There is a low level shut off , thats why I thought if it was just a little low after the motorhome was started the fluid level would rise with tempature and then it would continue to work fine ?
I am Brainstorming but when I cant figure something out it just eats at me ,
I will start the wiggle test next, The fluid was about 1/2 " low it says to check the overflow bottle right when the diesel burner kicks off at full heat it should be on the hot line so we added some, we have not shut it off long enough yet to see if it made a difference but it was not low very much ?
The igniter is sparking because it works fine after the water has been brought up to temp Once by the motor then it has to cycle on and off like normal as you use water or heat ? I was also thinking of a sensor But I ask myself why would it work after the water has been heated I could understand it if it would cycle once and then not work ? it would make more sense ????

[BrianE]

Larry, As I'm sure you know, there is an access panel to the thermostats above the webasto. They can be tested by simply jumping across them. A #14 wire is more than adequate. You can do this with the AH turned on when it won't fire up.

[Gil_J]

Larry,

The symptom makes no sense. I would think you might be on to something thinking the cold fluid may trigger a low coolant alarm. I assume it heats the domestic water in electric mode. If so, the AH coolant should be heated by the electric element. I forget what the alarm indicators on the remote panel, but recall there are several. Are there any alarms being raised? I can't imagine the AH not having it's own fuel tank pickup, but let me grasp at a straw. Could it be the AH is starving and when the engine is run in is bring fuel up on a line that's shared by the AH and the engine. This sure wouldn't be the way to plumb the fuel take-off. So, as I said I'm just grasping at a straw.

For Winnabago to say it should work that way suggest to me they know why. I'd asked them why as it would seem to be due to their installation.

[lbriant]

Thanks guys i hate being stumped but that gave me a little more ammo, You are right Gil it works in electric mode but I don't think it gets hot enough to fire off the aqua hot diesle burner ? makes me wonder about the fuel issue ???????
And I was not aware of the processes of jumping the sensors that would be a good try,
Lots of Brains on this sight !!! Best $25.00 I ever spent joining .)
Thanks for the different views !!!!

[lbriant]

Just found out as long as he does not shut off the electric unit the aqua hot works, if he lets everything go cold for a period of time it could take 30 to 45 minutes of running the coach motor before the aqua hot would work I don't think when the system is all the way cold the electric element will get hot enough or may take a very very long time I am not sure.
I will try letting everything go cold and if it dose not work I will start jumping sensors ??? because if it is running as long as the electric is on it must be pulling fuel ok,
I also wonder could there be any air in the system settling around the sensor area, this could be a stupid question ??
So no short bus jokes :o

[Gil_J]

?..because if it is running as long as the electric is on it must be pulling fuel ok...

In electric mode, the fuel system should not be energized.

[dale farley]

Larry,

My AH manual says it takes about 3 hours for the 110 to heat water.

[truxton]

Hi Dale,

Were you able to get some help from Tehachapi?

Later
bv

[dale farley]

Bernie,

I have talked to him several times, and he has answered some of my questions. He said he is sending some additional information to me so I can copy it. Thanks for the help.

[lbriant]

Dale, that would explain It, I don't think he ever tried letting the electric hot water run for 3 hrs to get the heat to run,
I am back to the sensors I believe,
Thanks again Guys

[dale farley]

As someone else suggested, I have been turning my diesel burner on for about 15 minutes and then switching to the 110 volt setting.

[truxton]

10-4 Dale

Later
bv

[dale farley]

Bernie,

I received a package from Mark that contains a 4'' binder with all my drawings and diagrams for the converter systems on bus. What a blessing! Now I have all the manuals and drawings. Thanks again for the info that made this possible. I see he is operating as Motorcoach Service in Techachapi, CA.

[garyde]

That is so nice of him. Maybe he would like to become a sponsor or a member. His Coaches are great coaches with great engineering.

[truxton]

Dale,
I'm glad he could help you.

Later
bv