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Topic: Aquahot won't restart automatically (Read 848 times) previous topic - next topic

Aquahot won't restart automatically

Working on our new-to-us (3 weeks) U295. The Aquahot fires up and runs every time the switch is turned on, goes through a normal heating cycle, but has been faulting on restart.  It did work all night once during the first week.  If I am nearby, it will always restart manually by cycling the switch or pulling the "B" plug out of the controller.  Checked the wiring, thermostats, flame sensor, but not the coil yet.  That was the one specific thing Roger Berke mentioned on his forum other than his usual "there are many things that cause intermittent operation" answer.  Here is what it has done every time in the many hours I have been working on it the last week or so:  after the initial heating cycle, the tank cools, the DC control thermostat closes, the blower starts up, runs the usual 10-15 seconds followed by the usual "whoof" firing noise, but the burner doesn't run (light goes out on the diesel switch at this point).  The blower runs its 2 minute shut-down cycle and goes off. 

It has never failed to start initially or failed to restart manually after a fault.  Other that the first week, it has failed to restart on its own.  One recent discovery is that if I cycle the switch after the initial heating cycle is finished, it will restart automatically after the tank cools. This thing has the problematic black Ukrainian control box and I should probably get the latest controller.  Just wondering if anyone has any guesses as to what I might be missing.  Thanks.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Aquahot won't restart automatically

Reply #1 –
Dave,  call me at 7 one 3  8 one 8  3234.  Rudy
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Aquahot won't restart automatically

Reply #2 –
Quick update and another question.

Rudy sent me a new controller and it has worked perfectly since I installed. 

My next concern is that the compartment next to the Aquahot is pretty warm.  100+F degrees.  According to my IR thermometer, the HWH box and aux compressor (both off) on the ceiling were 119 yesterday with the external temp in the 30's.  I will be installing a new Victron Multiplus II and Cerbo GX soon and may put them in with the new LiFePO batteries to keep them cooler.  Should I be concerned about the temp or not?  Thanks.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Aquahot won't restart automatically

Reply #3 –
Dave, you should have a 120v fan that sucks air out for the bay next to the AH space and exhausts it through the floor.  I am not sure of the on/off temps but you might want to make sure it is working. 120 seems hot to me.

Where are you going to put the MultiPlus II.  It is quite tall and will use all of the space between the floor and ceiling of the bay.  If it is charging at high rates it will generate heat as well.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Aquahot won't restart automatically

Reply #4 –
On Dave's '97 it was before the time of the heat exhaust fan unless one was added by a PO.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Aquahot won't restart automatically

Reply #5 –
I would definitely be looking into that.  I know my Xantrex unit has output falloff based on ambient temperature above 77*F.  Max operational temp is 140*F and at 120*F, it would be down about 20% output capacity.  Charger output would be down about double that.
Keith
2003 U320 38' #6197

Re: Aquahot won't restart automatically

Reply #6 –
Dave,

Some of the components in the aluminum Aqua Hot controller are sensitive to the higher heat - often reaching 140F. Many owners will leave the covers off the cabinet or better yet, move the controller to outside the cabinet and leave the covers on. The controller may last twice as long that way.
Jim

2002 U320 42'
Jim Frerichs
2002 U320 42'

Re: Aquahot won't restart automatically

Reply #7 –
Since I read on the forum about leaving the cover off, my Aqua-hot hasn't missed a
beat.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Aquahot won't restart automatically

Reply #8 –
Thanks for the replys.

Roger, as Mike said, no fan on a '97.  I was planning to modify the bracket where the Xantrex 458 is on the ceiling and mount the Multiplus II there.  Mounting this way is OK IF there is adequate ventilation.  With the working AH, I have axed that idea.  The upper battery rack where the 3rd 8D Gel sat is free and I might try that.  No gassing to worry about with the LiFePO's. 

Keith, your concerns are why I asked the question.  I can't image that the Xantrex, HWH, and ABS stuff is too happy in there currently.

Jim and Peter, the cover is off and the new controller (plastic 300-901) is laying off to the side of the case.  I could secure it and it leave the cover off.

When I was first working on the AH, there was even more heat coming off of it when running.  I pulled the burner for troubleshooting and after reinstallation it was better.  I should probably try to reseat it again.  Whatever the case, I need to do something.


Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Aquahot won't restart automatically

Reply #9 –
Dave,

Our coaches are just a few apart and I don't have the heat issues you are talking about. Sure seems like you need to do some snooping around and see where you are getting such a heat gain.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Aquahot won't restart automatically

Reply #10 –
Quote from: Dave Larsen –
Quick update and another question. I will be installing a new Victron Multiplus II and Cerbo GX soon and may put them in with the new LiFePO batteries to keep them cooler.  Should I be concerned about the temp or not?  Thanks.

Mounting a Victron Multiplus II

The Multiplus II CANNOT be mounted on the ceiling. It can be mounted on a vertical wall either in a vertical or horizontal orientation.

From Justin Cook:
"DO NOT mount to the ceiling. Horizontally on a vertical wall is fine though, or upright, or flat on its back on the floor!
The MP-II utilizes a single toroidal transformer mounted to the rear of the case (as opposed to the regular MultiPlus, which uses two toroidal transformers, one on each side of the case) so while it shouldn't be mounted to the ceiling since then the transformer would be hanging by its mounts and fighting gravity (and I find that gravity always eventually wins), horizontal mounting has no effect at all on the mechanical integrity of the transformer or its mounts."
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Aquahot won't restart automatically

Reply #11 –
Quote from: Roger & Susan in Home2 –
Mounting a Victron Multiplus II

The Multiplus II CANNOT be mounted on the ceiling. It can be mounted on a vertical wall either in a vertical or horizontal orientation.

From Justin Cook:
"DO NOT mount to the ceiling. Horizontally on a vertical wall is fine though, or upright, or flat on its back on the floor!
The MP-II utilizes a single toroidal transformer mounted to the rear of the case (as opposed to the regular MultiPlus, which uses two toroidal transformers, one on each side of the case) so while it shouldn't be mounted to the ceiling since then the transformer would be hanging by its mounts and fighting gravity (and I find that gravity always eventually wins), horizontal mounting has no effect at all on the mechanical integrity of the transformer or its mounts."

Thanks.  Yes, seeing that someone has done it doesn't mean that it is the correct way to do it.  The top battery tray is my current plan.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon
 

Re: Aquahot won't restart automatically

Reply #12 –
Being able to mount the MultiPlus II horizontally on a vertical wall or flat on the floor resolves a lot of logistical issues.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN