Aqua Hot 450DE totally out

[Uwe Schmalenbach]

I have a 2007 40' Contessa and right now the 450De Aqua Hot does not work at all. It does not heat on Diesel Burner nor Electric Element but even the light on the switch panel in the kitchen does not come on when one of the switches is turned on. None of the LED"s on the Electronic Controller panel in the curb bay above the unit are on. All breakers on the electric panel in the bathroom are normal. Up to yesterday the unit worked normally heating on the Diesel burner system.

Where do I go to even have any of the lights come on to help diagnose what the problem is?

[Lee Welbanks]

With my 06 Patriot Thunder there are some fuses and relays in the Front Run box for the Aqua Hot, I would assume yours would have about the same setup, check all the fuses that are labeled Aqua Hot.

[Steve Huber Co-Admin]

Uwe
Sounds like you've lost the 12V supply to the AqH. You can verify this by measuring the voltage between JP5 and ground on the AqH control board. The 12V supply is fused with a 20A fuse located in the rear (pass side) electrical bay. After opening the small door, you will will see the Big Boy relay. Just to the left and back from it is a PC board with fuses and a number of heavy gauge cables connected to it, etc. On the right side of the board there are a number of plug-in (automotive style) fuses. The top one (20A) should be the AqH supply fuse.
Steve

[Uwe Schmalenbach]

Thanks. I will try that. The strange thing is that after I drove the rig for about 30 miles all of a sudden the Aqua Hot was working again. Looks like I have some kind of intermittent wit the fuse or one of the connections.

[Randy Stephenson]

Uwe:

I had similar problem with with my Aqua Hot, the three zone pumps were not proving hot water to the center or bedroom heat exchangers.  I removed the panel and discovered there are three relays, only one was functioning.  I checked the tabs and bent them to be a tighter fit and have not had problems since.  You may want to check yours, if one pump is working, try switching out the relays, this is how I discover my issue.

Randy