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Topic: Replacement thermostat for my Atwood Hydro Flame in bathroom (Read 339 times) previous topic - next topic

Replacement thermostat for my Atwood Hydro Flame in bathroom

I was wondering if anyone on here has changed out their Atwood thermostat in the bathroom for a digital one?  Want to give that area an upscale look and have not found much on line.
Any information or help in changing this out to a nicer one would be most appreciated.  Anyone know if Foretravel upgraded this on their newer coaches?
Joe & Dottie Allen
Sold!  December 2023.      2000 U320; build # 5645
Our coach " Maxine"
Motorcade #  15922;  Escapee 150950; FMCA F330833; Boondockers Welcome;  Harvest Hosts;  Thousand Trails
'98 U320 from 2000-'06
USAF '62-'66

"Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for." ―Epicurus

Re: Replacement thermostat for my Atwood Hydro Flame in bathroom

Reply #1 –
Any stat you like will work as long as the output is a ground signal, not 12 vdc.  With only 2 roof airs, your A/C stat is for front and rear zones.  No control of bathroom.  Three roof air coaches will not need bathroom Aqua Hot stat.

Newer coaches with white painted heaters, 600D or 450D will use 12vdc signals
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: Replacement thermostat for my Atwood Hydro Flame in bathroom

Reply #2 –
Quote from: Rudy –
Any stat you like will work as long as the output is a ground signal, not 12 vdc.  With only 2 roof airs, your A/C stat is for front and rear zones.  No control of bathroom.  Three roof air coaches will not need bathroom Aqua Hot stat.

Newer coaches with white painted heaters, 600D or 450D will use 12vdc signals


Rudy, I have 3 roof airs, but still need the thermostat in the bath to control heat for bath and bays.  Not sure how FOT did the hook up, but the front thermostat controls all 3 AC's and AH heat for front and back of coach.  Thought I could just find a digital stat for the bath instead of the slider that sets the heat in there now on the stat.  May have to punt on this one, but wondering what the newer coach's have done to up grade that funky looking Atwood.  Thanks anyway!
Joe & Dottie Allen
Sold!  December 2023.      2000 U320; build # 5645
Our coach " Maxine"
Motorcade #  15922;  Escapee 150950; FMCA F330833; Boondockers Welcome;  Harvest Hosts;  Thousand Trails
'98 U320 from 2000-'06
USAF '62-'66

"Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for." ―Epicurus

Re: Replacement thermostat for my Atwood Hydro Flame in bathroom

Reply #3 –
My 01 U320 42 with 3 roof airs had a 5 button 3 zone stat that controlled all 3 Aqua Hot zones.

Any bathroom stat that sends a signal to the bathroom zone on the heater as a ground signal will work.  A 12 vdc signal can be converted to a ground signal
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: Replacement thermostat for my Atwood Hydro Flame in bathroom

Reply #4 –
Rudy your coach came from Foretravel with 3 roof ac's because it is a 42 foot. The other person's coach is a 40 foot and was wired at the factory for only 2 heat thermostat through the comfort control, and the Atwood thermostat was put in to run the bathroom zone. It doesn't control the  basement heat it has its own thermostat like all the other coaches with aqua hot. I don't know if you can find a digital thermostat that operates 12 volts.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Replacement thermostat for my Atwood Hydro Flame in bathroom

Reply #5 –
That is what I said, 2 roof airs, 2 zones of heat and an extra stat in bathroom for the 3rd heat zone.  That is exactly what I now have in the U320 40 footer.

Any stat sending a 12 vdc signal to the older Aqua Hots can be used to latch a cube relay.  The relay sends the ground signal to the heater to turn on a zone.
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: Replacement thermostat for my Atwood Hydro Flame in bathroom

Reply #6 –
Reminds me when I replaced the dometic air conditioners with atwoods and couldn't get the thermostat to work with it no matter what I tried. I had to put in all analog thermostats for my aqua hot zones to get it to work. What I found was that foretravel has a separate set of relays that control the aquahot relays. I had to add a separate 12 volt feed to get those to work.
I don't see why you couldn't use a regular digital thermostat for that circuit as long as you check to make sure it has 12 volts to it. It's just completing the circuit to the relays that are in the aqua hot area but not part of the aqua Hot.
'99 U320 40 WTFE
Build #5462,
1500 Watts Solar 600 amp Victron lithium
2012 Jeep Grand Cherokee Overland Hemi
Instagram bobfnbw
Retired