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AquaHot Problem

It seems that zone 2 (bath and bay) is not putting out heat.  What can I do?
Thanks, Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AquaHot Problem

Reply #1 –
Dumb, but did u turn the thermostat on in the bathroom?
1998 u320 3600 build 5200

Re: AquaHot Problem

Reply #2 –
First thing I would check is to see if the zone pump is running  and tap on the check valve for that zone. Sometimes the check valves stick and need a tap to get the flapper to free up. If the zone pump isn't running when the thermostat is on and calling for heat check your fuse for said pump. Yes both of these things are in the A/H unit hid in the belly of the beast.

Mike
Pamela & Mike 97 U 320

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

Re: AquaHot Problem

Reply #3 –
OK.  Seems to be working now.  Talked with Rudy and he told me how to troubleshoot the problem.  Also how to switch out relays so I have heat in the water bay should it fail again, as the temps are going into the 20s for the next 5 days or so in Missouri..

Another shout out to Rudy.  He is a master.
Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AquaHot Problem

Reply #4 –
what was the fix??
Peter    Alberta Canada
'98 U320 40'  Build 5359 M11 450 HP, Aqua hot, Blu Ox

Re: AquaHot Problem

Reply #5 –
To be honest, I'm not sure.  Before troubleshooting, I removed the cover to get access to the circulation pumps, increased thermostat in bath to get the heat exchanger blower going, and it started working.  Rudy said that the pumps are extremely reliable.  Could have been the relay.  Now, this morning, same problem.  I am going to swap out the relay and see if that fixes the problem.
Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AquaHot Problem

Reply #6 –
The relays are cheap and available at Grainger and other places.  Best to keep a spare on board.
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell

Re: AquaHot Problem

Reply #7 –
I have had a relay wiggle loose. Pull them out and reinsert. Put some (very little) electrically conductive grease or Corrosion X on the prongs.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: AquaHot Problem

Reply #8 –
Bingo! (hopefully). When getting ready to swap relays, all three had backed out against the retaining bands.  Maybe vibration from the blower motor over time?  Reseated and keeping my fingers crossed.
Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AquaHot Problem

Reply #9 –
Quote from: Yetch –
It seems that zone 2 (bath and bay) is not putting out heat.  What can I do?
Thanks, Mike

Dumb question but.... zone 2 (bath and bay)?  Does the thermostat in the bathroom turn on the basement heating? Does that need to be in the 'On' position for the basement heating to work?

Note: U320. My 'Zone 2' is the rear bedroom. I have a thermostat in the bathroom that is separate from the control box in the front.
Fred H.
1996 Foretravel U320 4000 Build #4993 (Previous motorhomes 1985 Airstream 345, 1977 Argosy 20)
Sevierville, TN
ViewRVs.com

Re: AquaHot Problem

Reply #10 –
No.  Separate thermostats with diodes in the wiring to isolate register fans to the called for thermostat zone.  See attached diagram.
2001 4010 U320 build #5865 "Bluto-d-Bus" since 09/18
2006 Honda Element ESP Toad
Full timing since 2016 in Western MT
Copilot: Sitka
1975 GMC 260 Avion: sold

Re: AquaHot Problem

Reply #11 –
I have always understood that even though there are two separate thermostats for zone 2, in order for the basement exchangers to operate, the on-off switch on the bathroom thermostat has to be on.
Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AquaHot Problem

Reply #12 –
Mike you may want to retention the retaining clips for the relays
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: AquaHot Problem

Reply #13 –
On my 1999 U320 the basement heaters will work regardless of whether the bathroom heater is on or not.  And the basement heater blower fans will work even if the aquahot is not running.
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell

Re: AquaHot Problem

Reply #14 –
Mike, one other thing to check is the ground post at the AH.  The nut can come loose and poor grounds result.


The thermostat in the basement has no off position.  If it gets set to the lowest position and outside temps are less than that the AH Pump and basement blowers come on.  This is very much not good if your coach is in storage for the winter.  You must add an on/off switch or a three wire plug to disconnect the basement thermostat.  That is what I did.

Looks like a switch would go in the black wire to the thermostat from terminal B in the drawing above, there must be a fuse in the open fuse slot.  You could pull the fuse but that means crawling into the basement.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN