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bizee · 07-14-2016, 01:02 AM

I just left the RV and can't remember the model #, but it is the Dometic 2 way (Propane and 120v) side by side that was on a bunch of RVs circa 2001 that many have done battle with over the years. Ours has not been the greatest either.

What we have struggled with since we bought this rig a couple years back are two main things...

It is tough to stay consistently cold in either mode, but especially propane when on the go. I think with the propane a big factor is because our pilot blows out every so many miles and we forget to check and reset it, so we'll lose some cooling and even though the fridge doesn't get opened ours has to be running to stay cold. I also theorize if it is blowing enough in there to knock the pilot out then it is probably also losing heat from the burner when it is operating that should be going into the unit.

The other problem we have is the freezer will get cold and the icebox will get nice and frosty eventually, but the fridge side can be tough to get cold enough to keep the food from going bad. We'll have to cycle food between the freezer and fridge to keep it.

FWIW I have moved the thermostat wire to the top, bottom, laying on the floor... really doesn't matter much it seems. We're going to get a fan in there this trip. It's just strange that the freezer gets enough cooling but the fins in the fridge side get so little. We also wedge the doors as tight as they can go to ensure they are sealed good. I'm also going to get an exhaust fan and see if that helps also.

What I want to try to sort out the most is the propane, especially why driving. I finally get to opening up the burner area and checked the operation. The flame is nice and blue, not really any yellow. It does seem maybe a little bit thin/whispy if that makes sense, like it is getting a tad too much air.

I know that sounds dialed if it is blue in but I wasn't sure if you can get a little more heat out of it by opening the regulator. It seems like it could help keep the flame more stable going down the road also. Is the regulator the hex/allen key, or is the round knurled screw right below the solenoid? I'm guessing that screw below the solenoid is a shutoff screw but I thought it would be best to get some feedback.

While inspecting in there I noticed a couple other odd things.

1) There is this metal cover that is just kind of laying over the burner area. It leaves such a huge gap that I wouldn't think it was the right part that went there except for the half circle cut out that matched the burner flew. I know it needs some air for making the propane mix but it seems evident this is why it is burning out going down the road. Has only modified that cover to block some of the wind from driving down the road, or is everyone just blocking off the lower vents to prevent blow outs?

2) Looking inside the galvanized housing that the flew runs inside I could see the tube of the AC system running up inside of it along with fiberglass mat insulation in it. Instead of being a round painted grey tube like the rest of it, instead there was barely any paint left, it was rusted, and it was not nice and round... it was slightly distorted with little dents and other distortions. It looks like the effect of the heat, but probably moreso the moisture getting trapped in the insulation caused the tubing to get rusted over time. I think has weakened the tube and allowed it to distort under pressure changes. It really looks like in the cold weather it would lower the pressure inside the pipes and where it was weakest it starts to cave in a bit here and there.

Has anyone else had this happen to their unit? It looks like it is a matter of time before it will deteriorate enough to leak. In the offseason is it worth trying repair by welding in a new tube and refilling it or are these really meant to be replaced every X years? The rest of the plumbing looks great, just that one part. Heck, it might already be leaking but then again my unit has been performing about the same for a couple years so I think it would probably be about shot by now if it is was. Hard to say.

bizee · 07-14-2016, 01:49 AM

After a little more research it sounds like the rusted pipe in the boiler area is the main failure point on these, so I'm not alone. I was thinking why not just braze in a length of copper pipe to prevent the rusting but it sounds like the ammonia would attack copper from what I understand.

Hopefully we can get another year of out it before it leaks out. Welding in new tube would be a quick and ez repair. The problem is where does one get the ammonia solution from with the right mix (ammonia, water, rust inhibitor) and right volume. My unit has a fitting on it to fill it, but not sure where to get it filled or get the stuff to do it myself. As much as I would like to replace it for a compressor style fridge we do so much boondocking that without getting a solar system it wouldn't work so I'd favor a repair option over buying a replacement if the coolant is available and inexpensive.

bizee · 07-14-2016, 02:09 AM

Another thought... I would assume that the freezer and fridge sides are not isolated, but after looking more at the design and at cut away pics of these units it showed tubes inside of tubes and made me think maybe it is possible...? I'm wondering if somehow I have a bit of blockage or something the fridge side plumbing and it is not cooling as effective as the freezer side. There are two sets of the zigzags on mine, one on the fridge and one on the freezer so if each zigzag group cools each side then it sounds like a possibility why the freezer side seems to work decent and fridge side is weak.

I hate the idea of the pull that unit out and tipping it over to try to remove blockage so maybe that will be the last resort.

YC1 · 07-14-2016, 05:21 AM

Welcome to the forum. You will find great information here.

Is the refer in a slide? If so, there should be a fan or two to move the air.

Is your vent tube cracked, and have you ever moved it from its original location?

The chimney tube does need to be cleaned.

If your refer is not in a slide and you have kept the chimney and burner clean then you can add a fan or two which always seems to help.

To do a search yourself, go to the top right of this page and find the little Google box. Do not try to do the forum search below that box. It does not work worth a hoot. Put your question in there and it will take you to many links on this forum.

Do a search for Fords refrigerator training for example and you should find a nice lady with many videos that are amazingly helpful.