The Fridge Cavity and Vents - Problems!

Fridge cavity - original

The picture shows how the fridge cavity looked for the propane fridge with the exception that I slapped some paint on the raw plywood floor after pulling the fridge last year and capped the propane supply.  The plywood floor is simply 1/2" plywood.  There's a 110V outlet on the left.  The propane and 12V wires are on the right. A yellow romex cable supplies 110V to an outlet on the other side from the inverter.  I added the inverter on/off switch above it.


They really gooped on the caulk.  A real mess.  Caulk is best applied in a smooth line that fills the cavity underneath but with only a little bit on the outside.  Goop like this is not only very messy but often hides voids that compromise the function of caulk.  They did need to caulk all the seams in the cavity for the propane to ensure that no combustion products could escape into the living area.  There was an inner section to seal the back of the old fridge from the interior of the cabin to prevent any CO.  I had to remove that because the new fridge is deeper than the old one was.  I ended up removing the old plywood base too.

Lower vent removed -  lots of rust inside and out

My refrigerator vents have been leaking with every rain so I wanted to fix them before installing the new fridge.  In removing the lower vent, I found the plywood floor is rotted near the vent and excessive caulk failed to seal the area. They put foam around the propane and DC wires and that was wet under the caulk - it has been dry for days so it wasn't new rain. I've got rust on the van ribs underneath caulk. Clearly, the goopy caulk failed to do its job.

Needless to say, I'm cutting a new plywood floor and need to fix the vents and treat the rust. I removed the bottom vent and found very little sealant on the vent cowl (probable source of the leaks) and a lot of rust on the van metal. So much rust, all the paint is gone under the flange and there is rust instead.  The vertical sides of the hole is the worst - there's only about half the thickness of the van metal left there.  Weird that they skimped on the sealant where it matters most and piled it on where a little would have been a lot better.  This was a case of the more I dug, the more damage I found.  Ugggh!

Cavity with floor, vent & inner sleeve removed.
Water heater on left, service box on right + wires &
propane pipes

Another thing LTV did on the bottom cowl is they cut the inner bottom lip and screwed the cowl edge to the plywood base so that it was flat to the plywood (this is where the plywood is rotting). Why they would do this is a real mystery as that lip is integral to the water shedding to the outside. All in all, I'm not very happy with the LTV build quality where it is hidden from view. Makes me think I should remove all the exterior holes and see if they are leaking/rusting too and reseal.

Search for replacement vent:
In trying to find a replacement, found that it is only available overseas on the Internet. There is no vent of that size (6 1/4 x 17 7/8") available in the US from any manufacturer. I can't even find the thing in Canada where these were made. I finally found what it is - the Dometic LS200 vent on both top and bottom. I sent an email to LTV to ask about replacement.  If I go to the UK to the couple of places that will actually ship overseas, the 2 vents would cost me well over $100.  And with the 12V fridge, I don't actually need the vents - but I have these leaking holes in the side of the van.

I emailed the manufacturer and he gave me a part number and said any RV dealer should be able to get the part.  I went up to a local dealer with my RV book and glad I did it in person.  The part number LTV gave me was incorrect and was for a larger vent size.  I kind of suspected that.  Luckily, the dealer had one of the right size in stock (not listed on their Internet site) and is ordering me the 2nd one.  They are expensive but less than ordering overseas.  $37.50 for each one including the inner cowl piece.  The label on the new vent says: Refer Vent BR3D2 bar code: 35062480,  Dometic LS200.

New vent and cowling - interior view

I found the old propane refrigerator vent info in my documentation and now understand why they did what they did with the vent.  They did it all wrong but it at least they had a reason for it.  The inner lip of the bottom of the vent is 3/4" tall and the propane installation has to have a gravity slope away from the base of the cavity.  Since they cut the hole in the side of the van to match the level of the cavity floor, they cut off the inner lip to achieve the required slope.  Obviously, they have a poor understanding of gravity to match their poor caulking skills.  What they should have done is position the vent hole bottom to be 3/4" below the cavity floor and mated the edge of the plywood with the top of that lip.  Then used a bit of flashing to seal the seam and force any water to go out the vent.  The vent construction is nicely thought out and would have worked fine if it had been installed correctly and not mangled.  I guess they did the rube-goldberg job because of where they wanted to put the fridge.  Lowering the hole 3/4" would have required putting the lower screws into the van rib area, but that could have been done without any real ramifications.  They already cut a piece of that rib to put in the water heater below.  The hole would still have been just above that rib.

Fortunately, my electric fridge will not pose any hazard with the lip a bit above the floor.  My documentation also showed me they didn't vent the old refrigerator properly.  The set that Dometic makes for these vents has the upper vent with a flue that is supposed to be connected directly to the refrigerator exhaust.  They never did that and installed the same vent as the bottom, so I'm sure that didn't help the old fridge any.  Nor the overall safety.  More reasons the 12V will be a better replacement.

Onto rust abatement and working on removing the rest of the caulk.  Got some caulk remover that seems to help that job some but it is still quite a slog.