Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: dsd on July 01, 2021, 07:14:49 pm
Title: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 07:14:49 pm
So coach is 2001 and this is a original cooling unit. History unknown. Have installed a ARP boiler control system and have never had great results. I do live in the middle of the desert also. I do not wish to entertain a conversion to full electric at this time. Dometic RM1282 So I have proactively been working the system and been learning along the way. Below 100 degrees the electric works. -4/32 deg overnight. Daytime it climbs to 20/65 degrees. It consistently seems to work better on AC power than gas. I have replaced regulator and adjusted to above 11" water level at the gas nozzle. Flame is robust and starts immediately and restarts if blown out immediately. I feel that it is probably at the end of its service life and a new Amish cooling unit is called for. BUT in checking doors seals today I came across another piece of the puzzle. The top and sides are above 100 degrees. Oat it probably the same but the rest of the cabinets are not that hot. Is I normal for these units to run this hot during operation? I still have concerns after I cleaned the fllu. Gas regulator (https://www.foreforums.com/index.php?topic=40758.msg406807#msg406807) Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: Travelin' Man (RIP) on July 01, 2021, 07:30:28 pm
You should consider that the refrigerator cavity is open to OAT through the vents, and that combined with the heat generated from the cooling unit could give you those readings. Is the side (bottom) vent in the sun?
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 07:33:27 pm
Under shade. I was quite surprised to see bedroom pocket door so hot
Title: Re: Dometic RM 1282 cooling issues
Post by: Travelin' Man (RIP) on July 01, 2021, 07:36:07 pm
Ammonia Refrigerator Hot Weather Mod (https://www.foreforums.com/index.php?topic=38090.msg368927#msg368927)
Title: Re: Dometic RM 1282 cooling issues
Post by: bbeane on July 01, 2021, 07:47:24 pm
I run 2 fans on thermostat controls on mine. Set to come on at 170 seems to work well.
Title: Re: Dometic RM 1282 cooling issues
Post by: Travelin' Man (RIP) on July 01, 2021, 07:51:19 pm
I run 2 fans on thermostat controls on mine. Set to come on at 170 seems to work well.
Same here, but it's not as hot where I am.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 08:16:06 pm
I've got double what ARP wanted for fans and am actually thinking of going to three fans at the exhaust cap to draw out more air
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 08:17:44 pm
It's so hot here a couple days ago fridge was off and the fans turned on Probably have to adjust them to a higher temperature setting
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 01, 2021, 08:34:46 pm
A few things. Check that the space between the cooling unit, and wall is 2"'s or less. We had to fill the space with foam sheets, to cause the air to go over cooling unit, and not pass by.
You can also make a small deflector at the bottom, to help air as it comes in the vent door, to go over cooling unit.
Another thing is, and I do this myself. In the worry of how cold it is, we tend to keep checking it, by opening the door. In the kind of heat you are in, this lets much cold air out, and hot air in fast. Also, you probably know this, if you put warm drinks or food in, it takes it down.
Lastly, do you have a circulating fan inside fridge? They work tremendously. Sorry your having this grief, been there many times with different coaches. Hot weather is not their friend, especially when the sun is blasting on the vent door.
And yes, a fan at the top vent really helps.
I have the same unit. Original cooling unit, still works steller.
Amazon.com: VALTERRA A10-2606 - Valterra Fridge Cool Fan W/switch A10-2606:... (https://www.amazon.com/VALTERRA-A10-2606-Valterra-Fridge-switch/dp/B0064E4K8O/ref=sr_1_15?crid=Y9UY7NLHQFYI&dchild=1&keywords=rv+refridge+fan&qid=1625186046&sprefix=RV+refridsge+fan%2Caps%2C235&sr=8-15) Chris
Title: Re: Dometic RM 1282 cooling issues
Post by: Dakota Slim on July 01, 2021, 08:45:16 pm
If the fins on the inside of the reefer are covered with frost & ice they won't cool properly. My Norcold has an automatic defrost cycle to prevent that but sometimes I use a hair dryer to de-ice the fins. It just takes a few minutes and I'll do it in the morning when it's cooler.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 08:58:49 pm
The ARP kit has two inside fans and comes with one outside but I had them add a additional outside fan that mounts to the outside access door. I am going to take the upper cap off again and check the gaps and and possible deflectors. The flue is about 18 inches from the top and and was thinking to add a augment or tube to help control heat from it. I think if there is more restriction to outside air to the sides and top of fringe that would help. Was real surprised to see the 110 temp with coach in the shade. It's got to be from the boiler. If there are fans at the top drawing hot air out that has to help instead of fans pushing hot outside air inside and around the cooler and mixing boiler exhaust into the mess also? Separating hot air and conditioned air makes sense to me. Frost in freezer but none in fridge. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: Pamela & Mike on July 01, 2021, 09:06:54 pm
Scott,
The 3 ID (induce draft) fan idea is what we did and it helped a bunch. One other thing you need to check (that happened to us) was the A/C unit was discharging hot air of the condenser right at the fridge roof cover. This caused a down draft where the hot air off the back of the fridge was coming out the back side vent. We had to build a deflector to redirect the air off the A/C unit. Seems like there is some pics. here on the forum of the deflector or that might have been back in the Yahoo days. I will have to look around for them.
Mike
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 09:25:18 pm
A few things. Check that the space between the cooling unit, and wall is 2"'s or less. We had to fill the space with foam sheets, to cause the air to go over cooling unit, and not pass by.
You can also make a small deflector at the bottom, to help air as it comes in the vent door, to go over cooling unit.
Another thing is, and I do this myself. In the worry of how cold it is, we tend to keep checking it, by opening the door. In the kind of heat you are in, this lets much cold air out, and hot air in fast. Also, you probably know this, if you put warm drinks or food in, it takes it down. Chris
So yes this is using a external thermometer. And not being opened during testing at all. With the inside fans never any frost. Freon ice cube maker will run down to -25 and was making ice last time it was operated. Haven't messed with that since. I really think the spacing and airflow makes sense will look tomorrow after other projects
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 10:25:00 pm
The 3 ID (induce draft) fan idea is what we did and it helped a bunch. One other thing you need to check (that happened to us) was the A/C unit was discharging hot air of the condenser right at the fridge roof cover. This caused a down draft where the hot air off the back of the fridge was coming out the back side vent. We had to build a deflector to redirect the air off the A/C unit. Seems like there is some pics. here on the forum of the deflector or that might have been back in the Yahoo days. I will have to look around for them.
Mike
That makes sense. The ac was not on much today so I can't say if it was a impact. I added a 50 amp surge protector
Amazon.com: Surge Guard 35550 Hardwire Model - 50 Amp: Automotive (https://www.amazon.com/Surge-Guard-35550-Hardwire-Model/dp/B01AASJHGO/ref=sr_1_18?crid=2GHNTCU2N27AY&dchild=1&keywords=southwire+surge+guard+50+amp+surge+protector+for+rv&qid=1625193128&sprefix=50+amp+rv+surge+protector+southwire%2Caps%2C240&sr=8-18) (Thank you Kieth) between automatic transfer switch and main electric panel today and ran ac on shore and generator to ops check it. If we are out using it would never shut off. Ive got a bunch of stainless sheets so a deflector would be easy. If it was not a parasite drag going forward and aft I see no problem with one. Ill steal some yarn from DW and check that out tomorrow. I see no reason for any hot air to be allowed past the back of the fridge. Ive placed 1 inch polystyrene foam next to the outside of a residential fridge and saw near inside temps outside of the fridge when removed after a couple hours in place, so 110 is fighting a loosing battle, maybe my cooling unit is good? I also checked all my door seals for leaks with a pyrometer and that is when I found the hi wall heat. Seals seem good. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 10:52:29 pm
May be I induced my problem by pushing in hot air from outside past fridge Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 01, 2021, 11:26:43 pm
May be I induced my problem by pushing in hot air from outside past fridge Scott
Two fans inside look great, But I personally like one down lower on the shelf around the food. Would it make a difference? I don't know I have the same refer, and NO external fans, it does fine. I was in Montana last weeked at 8K' altitude, sun burning on reefer door, and 85 temps. next to highest setting, no issues. Windows open,and NO air cond. going. Most the external fans I have installed, were horizons, top and bottom. The amish ones come this way too. Chris
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 01, 2021, 11:54:34 pm
So went back out and pulled top plastic stack off of roof again. Was looking at the area were the fridge is fitted in and there was a 1/2 gap alone the top edge that would allow boiler exhaust to go on top of fridge. Also found a 7/8 gap on the sides of the fridge hot section allowing heat to go to both sides of fridge. Only have about a inch clearance from cooling fins to outside wall. That was nice to see. So if the fridge was fitted deeper in the compartment that would reduce side leaks, but do nothing for the top. The one inch blue insulation is also free to move around and not secured to the top. I'll cut some fitted foam blockers to slide between blue factory foam and gap at top of fridge. First instinct would be to spray foam it, but I won't. Couldn't remove if you bonded the fridge in place. I am also going to build the flue extension I was thinking of prior to help control and direct the hot air out the top. Was going to put a box fan on for tonight, but after seeing all these issues no need to now. I still like the idea of pulling air out rather than pushing into the coach conditioned air space. I can see no reason not to seal and separate the hot and cold sides and top. I think the added BTUs from the gas explains why it worked better on electric after quadruple checking everything. Will be nice to see this hopefully resolved tomorrow. Somebody left the fridge (door) open to the outside. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 03, 2021, 12:14:48 am
So cleaned area and taped blue loose foam to top of coach with 600mph aluminum tape. Very thick and fireproof. Once it was pulled up was able to slide a 1" hi temp blue foam between the top of the fridge and the factory foam now taped up. Covered it with additional aluminum tape. Top side is now completely closed off from exhaust from boiler to super heat the top of the fridge. All exhaust when finished will be directed out the top vent. Will build a better seal for the vertical aft of the boiler to prevent hot air migrating to the back side of the fridge. The forward vertical side would be impossible to access from either top or bottom but it appears to be a tight gap so not going to worry about it. It is also the cooler side of the cooling unit. Unable to move fridge deeper in the cabinet. More tomorrow Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 03, 2021, 02:10:52 pm
Installed flashing along aft vertical side. Was only able to screw top and bottom but put a 90 degree bend on back side to reinforce and has a 1.5 overlap so that will be all it will be for a seal. Should cut down 95+% of hot air going to back side of fridge. Left the very top of flashing open and will install a louver do allow area behind flashing to vent out the top, but area behind has been insulated and taped off to protect conditioned air space. Started fridge back up at 93 deg inside and out. Let the beta test begin. Also measured the upper coach opening to be 5 3/8 by 24 1/4 inches and cap is 6 1/2 by 23 1/2 inches. Recalling considering delegating both my ARP fans on fridge inlet and having that power run to top and have 1-3 box fans drawing air out of compartment with switches to operate 1-3 fans as I deem needed? ARP fans draw .2 amps each. I think I can stay in the same range with three of the silent box fans. Haven't found out what there operational temperature limits are yet. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 04, 2021, 11:13:33 am
So ran for 21 hours. Last night when I walked away the fridge was at 10/70deg this morning it was at -2/32 degrees. Colder than I would normally run. The temp above the fridge is now the same as the rest of the coach at that same elevation. Inside temp this morning coach is down to 93 degrees. The roof is at the same temperature as the inside to within the last inch of the opening. So far very pleased. I will be making and installing a louver on the back side to allow hot air to rise but not mix from behind the flashing I installed. This is directly above the gas flue exhaust. Fridge was on AC up to now and just switched over to gas to measure temperatures several hours from now, mid day. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 04, 2021, 05:04:15 pm
So just checked on the fridge running on gas. Warmed up to 3/35 degrees. 93 degrees inside. Temp above fridge similar to the rest of the coach. Roof is at 108 all over. Little warmer around edges but much better than prior. Coach is still in shade and metal above it is four feet away and at 130 deg. Making advances I think. Scott Refrigerator Thermometer, Wireless Indoor Outdoor Digital Thermometer, 2 PCS... (https://www.amazon.com/gp/product/B07NRKWL5W/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 05, 2021, 11:09:13 pm
So added 1 inch of foam in inside edge above fridge in opening and covered with aluminum tape. Made and installed louvre to divert exhaust forward of aft end of cutout. Really surprised with results. Temperature of aft area is same as the flashing stopping further mixing of exhaust air. One inch in it was the same as the rest of the roof instead of being 140 degrees.so this is the most I can wish to accomplish. Ran on gas to take some measurements. Will run on electric overnight then run gas during the hottest part of the day tomorrow. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 06, 2021, 10:51:19 pm
So ran today during the blazing heat on gas. Started off at 0/30 ended up at 13/50 (unacceptable) at 6 pmOrdered fans to install in stack to draw air out. Yes it was stupid hot today. In the shade the backhoe bucket was 115 degrees? So my coach port is 16 feet tall about and the roof temperature underneath was 144 degrees. Top of coach was 117 all over in the shade. So I ordered fans to put in the exhaust chimney. Amazon. Amazon.com: be quiet! Pure Wings 2 140mm PWM high-Speed, BL083, Cooling Fan:... (https://www.amazon.com/gp/product/B07MJQJX6T/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) not what I will end up with just for trouble shooting. Upper tube was 210 at the far aft side. If this doesn't work I will order a new cooling unit unless someone has something else to try. $$1285 as I recall😒 Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 06, 2021, 11:01:52 pm
So ran today during the blazing heat on gas. Started off at 0/30 ended up at 13/50 (unacceptable) at 6 pmOrdered fans to install in stack to draw air out. Yes it was stupid hot today. In the shade the backhoe bucket was 115 degrees? So my coach port is 16 feet tall about and the roof temperature underneath was 144 degrees. Top of coach was 117 all over in the shade. So I ordered fans to put in the exhaust chimney. Amazon. Amazon.com: be quiet! Pure Wings 2 140mm PWM high-Speed, BL083, Cooling Fan:... (https://www.amazon.com/gp/product/B07MJQJX6T/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) not what I will end up with just for trouble shooting. Upper tube was 210 at the far aft side. If this doesn't work I will order a new cooling unit unless someone has something else to try. $$1285 as I recall😒 Scott
Personally,from my experience fans at the top blocks heat. Fans horizontal at the bottom,or lower on cooling unit really helps push heat out. That is the way some cooling units come.
Be thankful your fridge isn't in a slide out with no chimney, just another vented door. Then the fun begins. It is doable.
I just ordered one for a customer, new Amish unit, shipping is steep, and I have to pick it up in Spokane at the dock, to save cash.Otherwise to home, rv park etc. Almost $300.00 shipping Chris
BTW, I don't think your numbers are that far off, for being that hot, and on LP. How full is the fridge with food? How many times did you open it?
If it is working fine on electric, I would say it's not the cooling unit, you got something else going on.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 06, 2021, 11:07:54 pm
Chris that is exactly what I would do. For a 100$. I'll know in a couple days but I probably already know we're this is heading. I do know I'll install baffeling in new cooling unit and really seal up the compartment while I have it out. Again life is nothing more than a series of upgrades Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 06, 2021, 11:26:14 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
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: kenhat on July 07, 2021, 09:10:41 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
Title: Re: Dometic RM 1282 cooling issues
Post by: bbeane on July 07, 2021, 11:27:05 pm
Your doing about as good as your going to do
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 08, 2021, 09:35:40 am
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
Title: Re: Dometic RM 1282 cooling issues
Post by: Roger & Susan in Home2 on 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.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 08, 2021, 01:09:31 pm
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
Title: Re: Dometic RM 1282 cooling issues
Post by: bbeane on 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.
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 08, 2021, 01:19:02 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
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: oldguy on 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.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: mkc1962 on July 15, 2021, 06:50:41 am
Looks like a tight squeeze there to get it out.
Title: Re: Dometic RM 1282 cooling issues
Post by: craneman on 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.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 15, 2021, 11:29:35 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
Title: Re: Dometic RM 1282 cooling issues
Post by: mkc1962 on 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?
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 15, 2021, 01:50:48 pm
The cooling unit separated from fridge can go thru front door.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 15, 2021, 01:55:10 pm
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
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 15, 2021, 02:35:53 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 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
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on 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
Title: Re: Dometic RM 1282 cooling issues
Post by: craneman on July 15, 2021, 05:28:57 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.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 17, 2021, 03:35:51 pm
Is there any cooling component behind the aluminum plates below the ice maker area that should have there conductive paste replaced? Area around icemaker with fridge doors removed operates at -25 degree just amazing little Freon cooling unit. Wish the ammonia cooling unit worked this well. Hopefully new one will work better than old.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 17, 2021, 07:07:49 pm
Removed bottom panel and exposed this line that attaches to cooling unit with conductive paste and bottom plate. Will replace conductive paste and reinstall. Not going to disturb Freon system for fear of damaging it. Is this just to transfer cooling in freezer from top to bottom? Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 20, 2021, 10:15:11 am
Was notified new cooling unit would be delivered yesterday by end of day. At 2:08 was notified of a emergency reschedule. Today was notified cooling unit is now back in Grand junction Colorado. Kinda must of missed a turn. Only a 500 mile mistake. Hopefully will get this week. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 20, 2021, 12:06:35 pm
Was notified new cooling unit would be delivered yesterday by end of day. At 2:08 was notified of a emergency reschedule. Today was notified cooling unit is now back in Grand junction Colorado. Kinda must of missed a turn. Only a 500 mile mistake. Hopefully will get this week. Scott
Mine came to post Falls from Montana, then went back to Montana, then to Spokane. It's a mess. Chris
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 21, 2021, 10:56:24 pm
So received Amish cooling unit. I ran both cooling units side by side and the Amish is about 15 degrees cooler hanging on a similar rope. Both leveled. Great idea to run both and was nice to be able to compare apples to apples. Not my idea. Quite interesting that they start up and don't do anything till they actually basically seem to start all at once. Quite interesting to me anyway. So when I removed the heating elements on the old unit they both were corroded (red iron dust not yellow) would it be acceptable to use heat conductive grease IE; Dow 340? Quote ; DOW 340 resists changes in consistency at temperatures up to approximately 350ºF (177ºC) and has a maximum operating temperature of 392ºF (200ºC). Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: mkc1962 on July 22, 2021, 06:51:51 am
Scott, what's the purpose of the dielectric grease? Recounting old heat coil?
Glad new unit is colder.
Title: Re: Dometic RM 1282 cooling issues
Post by: mkc1962 on July 22, 2021, 07:39:12 am
Correction, silicone heat transfer paste. If its the white looking heavy, hard to smear grease, we use it all the time here at work on extruders (500+) heating sections to ensure proper heat transfer. Not sure about the brand though. Ive used it for anything that requires good heat sinking or heat transfer for over 40 years. A little goes a looooong way.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 22, 2021, 09:15:57 am
Zinc oxide and Polydimethylsiloxane. Yes it's a white paste. Should eliminate corrosion and improve electric heater conduction. And yes a little goes a long way. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: mkc1962 on July 22, 2021, 10:44:49 am
Yep, zink oxide was the word I was searching for....great for heat transfer, never seen it degrade or get hard well into the 5-600f range.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 23, 2021, 02:45:34 pm
So after all the additional insulation and seals reinstalled. Fridge with new cooling unit installed. Pretty tight going in four days off (Jiim) came down with lift and I used my jack to side into place past new seals. Probably not a approved installation procedure but since there is no book I don't know any better. It's in place, Ali lack is finishing. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 25, 2021, 12:01:16 am
All I lack is finishing. That was a understatement. Just finished 1/2 hour ago. The great cooler beat down. So after I had it in last night and before I started reinstalling everything just for some self gratification I turned it on to see it cool. Well it overtemped and shut down. I reset power and it started up and ran perfect. Cooling fans turned on after about five minutes and freezer coil temperature dropped to -20. All good. Boiler 167c. I shut it down and finished with all the removed panels inside. Fired it up again and went to overtemp at 220C every time I tried. I was never able to get it to restart again I fooled with till fairly late last night and finally walked away beaten. Badly. Today was a new day of getting whooped. I have double check level on everything. I took coach out into the driveway and and pitched it to the left then to the right, nose up tail up. No joy will not restart. What the heck? Sent out some requests for help and bounced ideas of several people. Decided to disconnect ARP fridge Defend and hot wired controller and pulled insulation back to expose boiler tube. Got my pyrometer out and fired it up. Temperature was similar for both ARP and pyrometer so at 220C there was nothing happening and upper boiler tube hadn't raised 2 degrees. The temperature held at 220 then all of a sudden the upper tube temperature climbed 50+ degrees and the bubble pump was finally moving fluid. Almost immediately boiler temp dropped to 212C and continued to cool down to were it's at right now, 167C. Fans came on after five minutes and I noticed that they were cycling. I did reconnect ARP controller, it is doing its job and will run overnight. I'm hoping what ever was causing the resistance to start will be resolved after it runs a few hours. The freezer was freezing and the fridge was cooling. Jim and Chris thanks for the needed help. It almost won that battle. Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: gracerace on July 25, 2021, 12:44:18 am
Persistence. Glad it's going.Glad I could be some help, but I think your the man. Cheers Chris
Title: Re: Dometic RM 1282 cooling issues
Post by: bbeane on July 25, 2021, 09:08:45 am
Scott are you running the ARP that you ran on your original dometic unit? The older ARP units will NOT work with JC refrigeration's units. AS told by ARP, the Amish units have a high temperature spike when they start up. Like to drove me nuts before I figured it out. Call ARP he will give the details, it's also in their instructions if you can find it. I don't remember what the version has to be to work.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 25, 2021, 10:21:22 am
Scott are you running the ARP that you ran on your original dometic unit? The older ARP units will NOT work with JC refrigeration's units. AS told by ARP, the Amish units have a high temperature spike when they start up. Like to drive me nuts before I figured it out. Call ARP he will give the details, it's also in their instructions if you can find it.
Well I regret not posting earlier. That explains exactly my problem exactly. I just couldn't understand why something so simple as a coffee pot wouldn't percolate. I'll reach out to Paul at ARP. Hopefully there is a work around to address the spike. I really like the idea of managing the fridge from overheat due to out of level. This morning Boiler temperature was 166c. Temps this morning were 0F and 30F and while I was walking out heard the ice maker drop the second group of ice with the Freon chiller off/disconnected from the ice maker (with a additional switch) it getting threw one start cycle really confused me to why it wouldn't participate after. Jim asked me last night if we ever feel like we are creating our own problems. Lol. :facepalm: Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: bbeane on July 25, 2021, 10:45:53 am
If you have an older ARP unit you will need to upgrade it to a newer unit.
Title: Re: Dometic RM 1282 cooling issues
Post by: wolfe10 on July 25, 2021, 11:00:10 am
If you have an older ARP unit you will need to upgrade it to a newer unit.
Yup, reach out to Paul with ARP.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 28, 2021, 12:34:41 pm
Prior to this had noticed a 5 degree split between theft ant right cooling fins inside of fridge. Left being colder. Removed right and verified good layer of conductive paste. Added a complete layer to tubes and mount and reinstalled. Now have a one degree split between the two? So 24 hour average and have been opening and closing fridge using ice also. Real happy with it so far. Thermistor set to warmest temperature and timer set to three Scott
Title: Re: Dometic RM 1282 cooling issues
Post by: Dub on July 28, 2021, 01:18:04 pm
Not to hijack but have 1 question. PO installed a new Dometic in my coach 10 years ago and I have no idea if arp was changed. I installed a JC Refrigeration unit last year and I didn't change arp but the unit works as it should. Should I have any concern over existing arp?
Title: Re: Dometic RM 1282 cooling issues
Post by: wolfe10 on July 28, 2021, 01:31:39 pm
Dub,
Call Paul at ARP.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on July 28, 2021, 02:00:34 pm
Not to hijack but have 1 question. PO installed a new Dometic in my coach 10 years ago and I have no idea if arp was changed. I installed a JC Refrigeration unit last year and I didn't change arp but the unit works as it should. Should I have any concern over existing arp?
Jim fourdaysoff installed Amish unit and never had to adjust his. Same unit as mine. Paul would know but from what I know if it's not going into overheat I personally wouldn't worry about it.. mine trips at 220C and starts at 225C
Title: Re: Dometic RM 1282 cooling issues
Post by: Dub on July 28, 2021, 02:04:38 pm
10/4 will call Paul. Want no issues.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on June 27, 2024, 12:54:56 pm
Hey just a follow up on my cooling unit. Coach was heat soaked yesterday at 97 degrees. Pretrip I started the fridge and turned on its icemaker. Within a hour it dumped its first tray of ice cubes. Fridge was at 70 deg. Today I dump a full container of cubes. Coach was set to 86 degrees and dropped it down to 82 for today. Fridge is empty but running at 33 and 0. With outside temps reaching like 109 today. It is in the shade but working great IMO. Glad I replaced the cooling unit.
Title: Re: Dometic RM 1282 cooling issues
Post by: Rudy on June 27, 2024, 01:16:56 pm
You might consider putting one gallon of water in the freezer and two gallons in the fridge so there is something to absorb the cold air besides just air
Title: Re: Dometic RM 1282 cooling issues
Post by: wolfe10 on June 27, 2024, 01:39:44 pm
Or better yes, those gallon jugs frozen from home freezer.
Title: Re: Dometic RM 1282 cooling issues
Post by: dsd on June 27, 2024, 03:37:09 pm
Oh it will be filled before we leave. Everything acts as a flywheel. Just nice to see the numbers about were they should be. I had separated power for the ice maker and the Freon chiller for the freezer. Allows the ice maker to work separately so if the freezer is cold enough it will make ice. Just not as fast.