Skip to main content ↑ ↓
Topic: 3 way Atwood water heater replacement (Read 862 times) previous topic - next topic

3 way Atwood water heater replacement

Not done yet (some leaks to argue with), but the new water heater is a vast improvement. Propane lightoff is instantaneous. The tank is insulated with a 2 piece styrofoam shell banded together.
The 110V electric setup now uses a 12V relay meant to control application of the 110V feed. Since my coach didn't have a separate control switch, I will add a local switch and power it from the pump power line. Your other option is to add it to the propane control line, but then the electric will always pair up with the propane. I much prefer the ability to run the electric stand alone...
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: 3 way Atwood water heater replacement

Reply #1 –
Dave.... do you have some pics of the replacement process?
The selected media item is not currently available.
George Hatfield

  Never ever use World Line Motors of Nacogdoches for service!

Re: 3 way Atwood water heater replacement

Reply #2 –
Not really. The pictures in the install manual do just fine. The heat exchanger connections (engine coolant) are on the bottom of the back side. The hot and cold connections are in the middle of the back, top and bottom. In the center of the back is the AC heater element and connection. There are only 4 'control wires' - white (+12V to AC element relay), Orange (+12V to propane control/start), blue (+12V out to 'fail lamp'), and green (ground). Take out the screws around the front of the unit, disconnect the propane line (after shutting of the propane at the tank!) and its ready to pull out. On mine, the hot and cold connections had to be undone in the back before you could pull it out. The heat exchanger had plenty of hose, and there was plenty of excess wiring to allow the rest of the connectionsobe undone with the unit removed. Its a lot easier to removed with the 10 gallons (70 pounds!) drained out. I had to add about a half gallon of lost coolant.
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: 3 way Atwood water heater replacement

Reply #3 –
Photos from our replacing our hot water tank
The selected media item is not currently available.

Removed original hot water tank.
Installed new 10 gallon gas & electric Atwood hot water tank.
Cold water supply changed from top of plumbing manifold to a cold water manifold valve
Hot water from tank changed from top of plumbing manifold to a hot water manifold valve.
Two top water manifold plumbing connections capped off.
A new hose ran from cold water manifold valve to hot water manifold valve to bypass hot water tank for winterizing.
Replaced all original water pump plumbing from bottom of fresh water tank to bottom water manifold bottom connections.
Ball valves installed on input and output water pump hoses to allow water pump to be replaced without having to drain fresh water tank or drain kitchen & bath water lines.
Installed a permanent water pressure gauge to monitor water pump output, city water pressure & hot water tank expansion psi.
Rerouted fresh water tank overflow hose from running over rear bulkhead to flowing through floor far from bulkhead.

Re: 3 way Atwood water heater replacement

Reply #4 –
Thanks Barry.  Nice job!  I really like the hot water heater bypass for winterizing. 
The selected media item is not currently available.
George Hatfield

  Never ever use World Line Motors of Nacogdoches for service!

Re: 3 way Atwood water heater replacement

Reply #5 –
Quote from: Barry & Cindy –
Photos from our replacing our hot water tank
The selected media item is not currently available.


Removed original hot water tank.
Installed new 10 gallon gas & electric Atwood hot water tank.
Cold water supply changed from top of plumbing manifold to a cold water manifold valve
Hot water from tank changed from top of plumbing manifold to a hot water manifold valve.
Two top water manifold plumbing connections capped off.
A new hose ran from cold water manifold valve to hot water manifold valve to bypass hot water tank for winterizing.
Replaced all original water pump plumbing from bottom of fresh water tank to bottom water manifold bottom connections.
Ball valves installed on input and output water pump hoses to allow water pump to be replaced without having to drain fresh water tank or drain kitchen & bath water lines.
Installed a permanent water pressure gauge to monitor water pump output, city water pressure & hot water tank expansion psi.
Rerouted fresh water tank overflow hose from running over rear bulkhead to flowing through floor far from bulkhead.

Will I need to remove strut bracket on side of bay door to water heater (now riveted on) to remove water heater for replacement?  It appears to cover WH trim molding.
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: 3 way Atwood water heater replacement

Reply #6 –
When I had MOT replace mine a couple of years ago, they just put the new 12V switch in the bay with the water pump and I left it on all the time.  The solenoid does make a slight eIectrical humming sound.  I could control the electric heater function with the existing 120V switch at the foot of the bed.  After I got home, I extended the wires up to the bathroom and moved the 12V switch up next to the water pump on/off switch.

Rich
Rich and Peggy Bowman
2002 U270 3610 WTFS, build #5939--"Freedom"
2022 Jeep Grand Cherokee Summit 4xe
SMI AirForceOne brake system
PakCanoe 15

Re: 3 way Atwood water heater replacement

Reply #7 –

Will I need to remove strut bracket on side of bay door to water heater (now riveted on) to remove water heater for replacement?  It appears to cover WH trim molding.
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: 3 way Atwood water heater replacement

Reply #8 –
Jack
I took mine out to reach the tank sensors. All I did was removed all screws around the HW tank and wiggled it out till I could take gas line of {lower left} then wiggled it out and had a table at the same height to set it on. Not a lot of room to disconnect the back of the tank. It has to come out level or you could mess up the Styrofoam around the tank. My wires were on top so as soon as I could I worked them to the side of tank to keep from skinning them.
With this said I think it will depend on how much slack you have on the wiring and hoses.
My two cents.
Good Luck 
Ron Clark
Sherwood,Arkansas
1999 U 295 40 foot Build # 5550
2020 Jeep Gladiator
Motorcade # 18173
FMCA # F485593