water heater replacment

[ragster_ga]

Robert,

One of the first projects on my PT-40 after purchasing last July was
to replace the leaking water heater. While I knew there was a leak,
the damage was hidden and not easy to identify. When I pulled apart
the water heater shelf area, there was softness in the wood below.
So it was clear that it had been sitting wet for a long time.

In my case, I decided to do a total bed/rear decking replacement. I
spread the work out over a week. My queen bed is centered and
against the rear cabinets.

I used the Atwood EHM11SST tank to replace the original. It has all
the connections on one side and stainless steel housing. You can
find them for around $425 if you shop.

On the '86 PT-40, there are two pieces of wood on top of the engine
housing. One goes from the queen all the way to the rear under the
cabinets. It has a cut out for an access door to the engine
compartment. The wood is on top of a small felt pad which is on top
of the steel engine housing.

You should pull the wood over the engine access door to determine if
the felt pad underneath has any moisture. If it does, it will be
trapped between the wood and the steel and never escape. Eventually
you will have mold and dry-rot. If this pad is dry...you are a step
ahead.

I removed all the rear cabinets below the overhead. The overhead is
self supporting and can remain. There is a heat exchange in the
center-bottom of the cabinets that is used for bedroom heat. I did
not remove the heat-exchanger, but I did remove the screws holding it
down and removed the wood from under it. This kept me from having to
undo the hot water hoses from the engine. I might be easier to
remove it if you have to.

Hopefully, when you remove the HWH, you will not have had any water
get under the wood. If you did, and it is contained to just one
local area, you could possibly cut out the damaged section and leave
the remaining.

In my case, I wanted to be sure I got out all the moisture so I
removed everything. I touched up the steel housing (a few
scratches). Sealed all the existing screw holes from the old plywood
mount holes. Put down a thin foil insulation pad. Then put down the
plywood. I pre-drilled each hole through the wood / engine housing
and attached the new wood with stainless steel screws.

Take plenty of pictures to remember how it goes back together if you
have to disassemble anything. There are a lot of very similar parts
in removing the cabinets, that took me a few extra minutes to
remember how to get it back together...however it will only go back
one way.

The best choice for wood in my opinion is a Marine Grade Plywood.
Expensive, but it has glues that will not break down to water
exposure. You can special order it through Lowes here in my town.

Another choice that might be OK would be to use a copper based
pressure treated plywood. Do not use the arsenic based wood, unless
you want to expose someone to the arsenic .

When I put the wood back down, I did it in three sections. One
section was the width of the coach, and went from the back wall to
about one inch forward of the rear cabinet wall (just about 1/2 inch
to the rear of the engine access door). Then I put a piece to the
left of the access door and another piece to the right of the access
door. I used 3/4" plywood. I also put down new wood for the access
door. For it, I used a 1/2" piece because the steel access door is
raised about 1/4" from the rest of the housing.

Hopefully in your case, you won't have to remove any of the decking.
Be sure that no water has gotten between the wood and the steel
housing. If that happens, it will not be apparent by looking at the
top of the wood, but hidden problems will arise over time.

If you don't have to replace any wood and not remove the cabinets, 1
day should be no problem. It will be tight getting the HWH out and
the new one back in, but it will fit through the door opening. You
will need to remove the door and the shelving/panel above, in the
rear, and to the driver's side of the HWH to make it easier.

I tried to find a pan to put under the HWH but could not find one to
fit. I still would like to custom make a pan and set it under the
HWH and have a drain out the rear through the engine compartment in
case of a leak. I did use 3M 4200 marine caulking to seal the seams
to prevent water penetration.

The biggest thing you will need is moral support if you have to pull
it all apart. My old body complained for a few days afterwards from
all the bending and weird positions required to remove the rear
cabinets.


Glenn Allen
1986 PT-40
Marietta, GA

--- In WanderlodgeForum@yahoogroups.com, "Robert & Teri Rahn"
wrote:
>
> I was able to get back to the water heater and check for leaks. It
is
> not leaking out of the pressure relief valve and there is no
leaking at
> any of the pipes. It is a little wet way back at the corner back
there
> which must be directly above the hole where the water is dripping
out.
> I turned the water heater off a few days ago and water is still
> dripping slowly out of the hole in the engine compartment. So the
water
> heater must be rusted out and the leak is coming from below it.
Where
> is the best place to buy one of these heaters and what is the best
way
> to remove it? It looks like it is going to be quite a chore to get
it
> out of there.
>
> Robert Rahn
> Kalispell, Mt.
> 1988 PT 40
>