Last long trip precluded this install, so we had to use the original Atwood 6 gallon. Worked, but was not that nice, IMHO. Finally had down time to pull trailer apart and install the shiny new PrecisionTemp 550 I ordered several months ago
Went into a 22' 2007 FB International CCD. Pulling the old Atwood was a bit of a beast, because it was literally glued in place with TONS of caulk on the inside, apparently from the factory.
Lots of blue tape to protect the aluminum, and gentle pry and cuss to get it out.
Had to enlarge the top of the opening quite a bit to get the heater in--took two passes to get the hole just barely 1/8 taller than the heater. Its now in sealed with a layer of wide butyl tape covered at the edges with silver caulk.
Some comments, issues and cautions to note during this learning experience:
1. Had to relocate the original Atwood propane supply line, but with a bit of work was able to connect it up using original parts.
2. Crimping PEX in the tight confines of the closet was interesting--I'm sure the neighbors did not appreciate my language and body English whilst I tried to get the huge crimper in there.
3. Start the heater up without propane turned on the first time--the exhaust vent was full of styrofoam pellets chafed from the packing material, and they went everywhere, and a few melted to the screen. Better to blow them out cold.
4. It is much, much quieter than the Atwood, and puts out nice reasonably hot water. Better and more constant temperature control than we got from the Atwood as well.
5. The aluminum (bare) door I got with it is just about 1/4 inch or so WIDER than the Atwood door, so I had the joy of disassembling the lower rub rail, shortening it in place with a hacksaw and a block of wood to protect the side, and putting it all back together.
6. Door is really just BARE aluminum--I get to clear coat it with something to protect it. Any suggestions?
7. Original heater support block on the closet floor needed modifying to support this heater properly. Flipped one way, its too short, the other was too tall.
8. Miracle of miracles, the hinged cover in the bottom of the closet STILL fits properly even though this new heater is a bit taller...
9. No obvious leaks, either...
It was a longish day in the (unusual for SO CAL) rain, of course, but it worked out and should be quite nice for hotel showers on our next 5K mile trip...
Pics look similar to the previous Post. Anyone need a perfectly usable 6 gallon Atwood with lots of caulk on it and low usage hours?--send me a PM.