Dometic RM 1282 cooling issues

Topic: Dometic RM 1282 cooling issues (Read 2992 times) previous topic - next topic

Re: Dometic RM 1282 cooling issues

Reply #25 – July 06, 2021, 11:16:20 pm

So I was thinking that the negative pressure to draw heat out would reduce the amount of heat energy being pushed in to the conditioned air space. Ive sealed up as much as possible but still have a leak next to the sliding door going into the bathroom. I see about a 3 degree rise. Much better than were I started but unacceptable if I have the unit out.
Scott

Re: Dometic RM 1282 cooling issues

Reply #26 – July 06, 2021, 11:26:14 pm

Quote from: gracerace – July 06, 2021, 11:01:52 pm

BTW, I don't think your numbers are that far off, for being that hot, and on LP. How full is the fridge with food? How many times did you open it?

If it is working fine on electric, I would say it's not the cooling unit, you got something else going on.

Will operate on electric tomorrow. Fridge empty with several gallons of water inside. Did not open once. External remote pyrometer
Thank you
Scott

Re: Dometic RM 1282 cooling issues

Reply #27 – July 07, 2021, 04:43:54 pm

So running on electric today. Doors never opened . Night time low was 95 deg. So at 1:30 OAT is currently 109 degrees. fridge is 2/33 degrees on coldest position. Seems to work better on AC power than gas. Next 5-6 hours will be the real test.
Scott

Re: Dometic RM 1282 cooling issues

Reply #28 – July 07, 2021, 04:50:44 pm

Heating element is attached directly to cooling unit, most heat directed to cooling unit. Gas flame heats cooling unit, with wasted BTU's.
If it cools on electric, but not gas, something else is going on also.
Chris

Re: Dometic RM 1282 cooling issues

Reply #29 – July 07, 2021, 08:27:06 pm

So into my second hour at 111 degrees under AC power temp has climbed slowly up to 8/38. Still planning on additional fan testing, but this is getting closer to working. But how do I keep DW out of it from noon till ten o'clock
Scott

Re: Dometic RM 1282 cooling issues

Reply #30 – July 07, 2021, 09:10:41 pm

Quote from: dsd – July 07, 2021, 08:27:06 pm

So into my second hour at 111 degrees under AC power temp has climbed slowly up to 8/38. Still planning on additional fan testing, but this is getting closer to working. But how do I keep DW out of it from noon till ten o'clock
Scott

Put her wine in a cooler.

see ya
ken

Re: Dometic RM 1282 cooling issues

Reply #31 – July 07, 2021, 11:27:05 pm

Your doing about as good as your going to do

Re: Dometic RM 1282 cooling issues

Reply #32 – July 08, 2021, 09:35:40 am

Quote from: bbeane – July 07, 2021, 11:27:05 pm

Your doing about as good as your going to do

So last night at 8pm it was a 9/42 degrees running on AC. This was the best it's been. This is also not being opened and closed 1/2 a dozen times. Getting closer to ordering a new cooling unit. This is much better than prior and we may try to use the way it is for a bit longer. I'll make some phone calls today. Thanks for the input, it's good to hear we at least close. If you run the ice maker 110v it cools down to -25 in a hour. Would really like to be able to run on gas and not worry about it. Definitely not to that point.
Scott

Re: Dometic RM 1282 cooling issues

Reply #33 – July 08, 2021, 09:47:01 am

That is about as good as ours was, maybe better in the freezer. Shelf life at 42° for milk etc is pretty short. If we started it up from being off it would take a couple days to get to those temps.

Pulled it out, saved the wood panels, sold it for $350 as I recall and put in a 18 cu ft Samsung that cost just under $1000. Added a floor to ceiling pantry next to it. The refrigerator and pantry space work very well. Another option.

Re: Dometic RM 1282 cooling issues

Reply #34 – July 08, 2021, 01:09:31 pm

Quote from: Roger & Susan in Home2 – July 08, 2021, 09:47:01 am

That is about as good as ours was, maybe better in the freezer. Shelf life at 42° for milk etc is pretty short. If we started it up from being off it would take a couple days to get to those temps.

Pulled it out, saved the wood panels, sold it for $350 as I recall and put in a 18 cu ft Samsung that cost just under $1000. Added a floor to ceiling pantry next to it. The refrigerator and pantry space work very well. Another option.

Yep
If you give a mouse a cookie. Never ending.
Would like to keep gas fridge for a while longer, even if it means replacing a decaying performance cooling unit. It's not the 2k fridge it's the life limited batteries( I hate batteries), inverters, conversion, learning curve, BUT all paths seem to lead back too that eventually. If knew these better it would make the choices less painful. 110 outside temperature is also a multiplying factor to add into this. It's many times better than it was two weeks ago. Need to talk to fourdaysoff and see how well his Amish cooling unit is doing

Re: Dometic RM 1282 cooling issues

Reply #35 – July 08, 2021, 01:16:03 pm

Scott, I have a Amish cooling from JC Refrigeration, been happy with it for 4 years. HOWEVER it's still an ammonia based unit, it does what it does. Don't get your hopes up too high, you still have a 20+ year old box with about 2" of old insulation. IMHO RV fridge at 100+ temps just can't over come.

Re: Dometic RM 1282 cooling issues

Reply #36 – July 08, 2021, 01:19:02 pm

Quote from: dsd – July 08, 2021, 01:09:31 pm

Yep
110 outside temperature is also a multiplying factor to add into this.

Especially if the sun is pounding on the vented door.

I agree with Bruce

Chris

Re: Dometic RM 1282 cooling issues

Reply #37 – July 08, 2021, 03:00:02 pm

So no sun, under metal shade. Spoke with tech at JC refrigeration and went over every thing done so far. Installing external box fan on top of roof to draw air out of unit just for testing. From everything I've read they do have a lifespan and it is twenty years old. Tech said it should maintain 36 degrees on mid setting at 110 degrees outside while being used conservatively in daily use. Think I'm closer to ordering a new cooling unit. He also mentioned raising the flue height and upper cap to help heat separation and exhaust

Re: Dometic RM 1282 cooling issues

Reply #38 – July 08, 2021, 03:23:15 pm

Scott I don't know much about the Dometic Fridge but I had the same trouble with
a Norcold in my last coach. It worked better on gas so when I bought this coach I put
in a 13 cubit Frigidaire which my wife got at Costco for 5 hundred and something as
I didn't want to go through what you going through. During the hot spell hear it work
perfectly. When I bought this coach it came with a new inverter so I didn't have that to
get. Hope you get this sorted out.

Re: Dometic RM 1282 cooling issues

Reply #39 – July 09, 2021, 09:30:42 am

Not looking good . DW said it was budgeted when we bought the coach as being bad. 20 years old! Order a new one and get it fixed. Was at 32 degrees this morning but won't hold if used. Ordered the complete kit with new electric heaters and fans. Fingers crossed. Thanks for all the input.
Scott

Re: Dometic RM 1282 cooling issues

Reply #40 – July 15, 2021, 01:01:06 am

Finally got fridge moved inside coach. Because my slide is still not repaired and secured closed I removed the dinette to accommodate removing the fridge. Sidewalls are now accessible as the top. Sides will accommodate 1/2 inch of foam on each side . Will install a sheet of 3/8 on both sides and bond on to existing foam. The ceiling will accommodate adding 1 3/4 foam on top. This was evident with the hi temperatures above the fridge. As the fridge is pushed in place the last inch of movement I will preprep 1/8" foam seal to stop any air movement from the hot side of the fridge to the conditioned air space of the coach. This should make a big difference in coach temperature both hot and cold. I genuinely was surprised to see such a big opening from the outside in. This will also affect dust collecting along the top and side of the fridge. Also found condenser fan noisy. Will relube or replace. Also removed about a pound of mud dauber nests. Ive got to be getting to the end of them, I think I've almost looked everywhere now.
Scott

Re: Dometic RM 1282 cooling issues

Reply #41 – July 15, 2021, 06:50:41 am

Looks like a tight squeeze there to get it out.

Re: Dometic RM 1282 cooling issues

Reply #42 – July 15, 2021, 11:02:54 am

When I helped my brother install a new cooling unit in his Monaco. We put it face down as that was the recommended way according to his instructions.

Re: Dometic RM 1282 cooling issues

Reply #43 – July 15, 2021, 11:29:35 am

Quote from: craneman – July 15, 2021, 11:02:54 am

When I helped my brother install a new cooling unit in his Monaco. We put it face down as that was the recommended way according to his instructions.

Yes that is my plan. Currently cleaning up and resealing the compartment it lives in. Haven't received cooling unit. Will also be using orange fire stop foam to seal up all the openings that wires run thru. Attempting to tighten/seal up the conditioned air space as much as possible. Will drag out the foam cutting table and custom fit foam for the top side and seal it in place. Hoping to get a near total seal at the back of the refrigerator unit to sides and roof. Haven't figured out bottom yet although it will probably just be more 1" x 1/8 foam seal. It's at the lowest point so not too worried about it , but since I never want to go back will look at it now. Will also be reducing the 1" clearance at the back of the cooling unit to improve airflow over cooling unit on the vertical wall.
I also noticed that there was inaddition to the mud dauber nests a lot of settled dust on the cooling unit coils. I will be opening up in the future the lower vent and use my leaf blower to help un settle that dust. I do believe it would contribute to insulating condenser coils and reduce efficiencies. I wish I had done this prior since my cooling unit almost worked well enough prior. Shame its not water water proofed and you could wash out with the hose. No way to brush either. Blowing it out annually is as good as it gets unless someone else has a idea.
Scott

Re: Dometic RM 1282 cooling issues

Reply #44 – July 15, 2021, 01:29:32 pm

Oh well....use the old one in the corner of your shop for a high end beer cooler!!....I had an old 50 year old amish ammonia based cooler doing such till about 2 years ago, when it developed a slow leak and eventually just wouldnt keep em cool enough for my liking.

Are you going to have to take out any front seat, door, etc to get in/out?

Re: Dometic RM 1282 cooling issues

Reply #45 – July 15, 2021, 01:50:48 pm

The cooling unit separated from fridge can go thru front door.

Re: Dometic RM 1282 cooling issues

Reply #46 – July 15, 2021, 01:55:10 pm

Quote from: craneman – July 15, 2021, 11:02:54 am

When I helped my brother install a new cooling unit in his Monaco. We put it face down as that was the recommended way according to his instructions.

Just thinking as I was lubricating the Freon condensing fan bearing, may not want to lay flat because of Freon system for ice maker? I know your not supposed to lay a conventional fridge on there back. May only go 60 degrees angle to keep bottom down to prevent oil getting on top. I'll give a call to my ac guy

Re: Dometic RM 1282 cooling issues

Reply #47 – July 15, 2021, 02:35:53 pm

Quote from: dsd – July 15, 2021, 01:55:10 pm

Just thinking as I was lubricating the Freon condensing fan bearing, may not want to lay flat because of Freon system for ice maker? I know your not supposed to lay a conventional fridge on there back. May only go 60 degrees angle to keep bottom down to prevent oil getting on top. I'll give a call to my ac guy

I have done probably 30 cooling units. It will be next to impossible to do it standing up. Not saying you can't. I have done one's with compressors, just don't leave it laying down any longer then you need to.

Here is a video, doing one with compressor:

https://jc-refrigeration.com/wp-content/uploads/2019/09/Dometic-Cooling-Unit-Models.mp4

Here is the one Im installing next week in a FT. It has a compressor

Only challenge will be, it's had a rebuilt dometic cooling unit already installed,so it will be hard to get the old one out, with all the spray foam they use, as noted in video. Fun times

Chris

Re: Dometic RM 1282 cooling issues

Reply #48 – July 15, 2021, 05:05:17 pm

Chris very informative video. Thank you for posting. Never underestimate the power of the spray foam. You never know how strong something is till you remove it. Foam, welding, composite repairs. When I was pouring the floor to our house I used 8 foot 4x4s for temporary support and to hold them in place used a small wood wedge and spray foamed about 2x3 1/2 inches on the end. Next morning I went to remove shims and all the 4x4 were swinging in the air with that small patch of foam holding them up. Beams had got hot and arched up.
Thanks again
Scott

Re: Dometic RM 1282 cooling issues

Reply #49 – July 15, 2021, 05:28:57 pm

Quote from: dsd – July 15, 2021, 01:55:10 pm

Just thinking as I was lubricating the Freon condensing fan bearing, may not want to lay flat because of Freon system for ice maker? I know your not supposed to lay a conventional fridge on there back. May only go 60 degrees angle to keep bottom down to prevent oil getting on top. I'll give a call to my ac guy

My refrigeration customers told me that the A.\C or refrigerator must be put in the correct position for the same amount of time it was laid down to allow the oil to return. They trucked equipment to the jobs on their sides and upside down.

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