Dometic RMD8555 Frustration

[rbryan4]

Appliances designed to work with low pressure (11"wc pressure) work best when the pressure is in that range. When I installed the MEGR -253H I measured the pressure at 12. That was in the acceptable range so I didn't adjust it. The stock regulator measured 10, but it fluctuated a bit. The new one did not. Perhaps that's the difference.

[John David]

I beleive you are right. Its the variation thats the killer, not the level. A larger header hose would help but those are frowned upon.

We have spent 25 days in our 19 so far this summer. We have 320 watts of solar (theoretical max) in two fixed panels on the roof. We have an RMD 8555 fridge.
We travelled with the fridge on 12V (solar), including rest, lunch and gas stops. Throughout all that our fridge kept at 7C with three bars and 5C with four bars. The solar had no problem maintaining the fridge. Some days we would draw down the batteries a little and others we would maintain and even gain. We found its best to minimize fridge door open times. Ambient temps were from 11C to 30C.

Prior to trying the solar stress test we ran the fridge on propane and at elevations from seal level in Prince Rupert BC to 7600 ft at the kootenay skyway. We live at 3600 ft ASL. The propane never failed to light first time every time.

So all in all we are fairly happy with our fridge performance.

John

[Klem]

Originally Posted by rbryan4

Appliances designed to work with low pressure (11"wc pressure) work best when the pressure is in that range. When I installed the MEGR -253H I measured the pressure at 12. That was in the acceptable range so I didn't adjust it. The stock regulator measured 10, but it fluctuated a bit. The new one did not. Perhaps that's the difference.

Smoother is better! Changed ours out to same as yours so we'll see. Thanks

Which device did you use to measure? I see tube with dye and pure electronic.

[Brian B-P]

Originally Posted by rbryan4

... The stock regulator measured 10, but it fluctuated a bit. The new one did not. Perhaps that's the difference.

Bingo.
Ideally any regulator would put out a constant pressure, but in reality that doesn't happen, ever. Even though RV propane regulators are two-stage (so they should be more consistent than the single-stage regs used for grills), the output pressure still varies with input pressure (which way depending on regulator design and operating conditions), and with flow (higher flow causes less output pressure).

A high-flow regulator will likely drop less from the desired pressure as flow increases than the standard regulator.

[rbryan4]

Originally Posted by Klem

Which device did you use to measure? I see tube with dye and pure electronic.

I just use a cheap Dwyer tube manometer like this one. But you can easily make your own with some plastic tubing.

http://m.rverscorner.com/?url=http%3...referrer=#2684

[Kountrykamper]

This one is a little more money but is easier to use.

https://www.amazon.com/Yellow-Jacket...ssure+test+kit

[padlin]

Cost me $2 for 5' of 5/16 ID tube and about an hour to make one.

[Kountrykamper]

Originally Posted by padlin

Cost me $2 for 5' of 5/16 ID tube and about an hour to make one.

I use it several times a week in my business so a $2 price of tubing don't cut it. Need something that stays in the truck box.

[Take_a_hike]

Originally Posted by Drumstick63

Another Update On Replacement RMD8555
I originally started this post last fall and gave an update earlier this summer on our replacement RMD8555. I thought I might give a new update as my wife and I just spent seven nights at Topsail Hill State Park in Florida with some pretty hot weather (heat index over 100 some days).

The only thing that I have changed since our earlier trips was to move the Thermistor off of the fins and move the External Fan Thermostat right next to the water tray. I moved the External Fan Thermostat down the pipe and right next to the water tray as the location were it was originally placed seldom got hot enough to turn the fans on. This new location is closer to the heat source and seems to get hotter. Keep in mind that we freeze water bottles before our trips and place in both the fridge and freezer.

From the time we left until we returned home, the fridge temperature ranged from 27F to 35F. The 35F reading came while traveling with the unit on battery. We saw 34F one time while camping when we loaded some items from the grocery store. For 98% of the trip, the temperature ranged from 28F to 32F, with the temperature staying 30F to 31F most of the time.

This might be a little on the cold side as grapes were covered in a thin layer of ice when removing them from the fridge. We even had water bottles still frozen solid in the fridge after seven days. We are still happy with our replacement RMD8555. Hopefully this performance will continue.

Thanks,
Mark

We have been camping in 100° + during the month of July and have been pleased with our refrigerator temperatures. The dangling thermistor "fix" is all we had done.
Big change from our trip home from ETI in March! The outside air temperature was cooler than the refrigerator!

[Steve Clark]

Hi All, Just a little feedback on our RMD 8555 performance this past week-end.
At our home we pre-cooled the fridge on propane for 24 hours, then switched to battery for travel. Everything we put in the fridge was pre-cooled at home. We camped in Red Bluff, Ca., Thursday-Monday and had full hook-ups at about 1100 ft. elev. We switched to shore power for the four days of camping. Fridge settings were on 3 DOTS at all times. Daytime temperatures were 100* F. Nights were high 60's-70*. We were in full sun exposure, with no shade except for awning. We did not put water in the cup, and have never done so.
The freezer and fridge remained ice-cold the entire time. An ice block in the freezer remained frozen, beer and all fridge contents remained ice cold the entire time.

We have the stock RMD 8555 and have made no alterations since pick-up in April '16. We couldn't be happier with the performance. We have no experience with the previous single-door model, or the newer Americana model, but so far we have no complaints with the RMD.

[LeonW]

We have had our fridge for a bit over a year, and it was always marginal -- temps in the high 30s, and sometimes the 40s if the weather was really hot.

I made a couple of changes this summer:
1) I replaced the propane regulator with this one.
2) I moved the thermistor from its usual location to the very top of the fins. it is just resting there -- not screwed in.
3) I got some the sensors that Fudge Brownie recommended. I don't believe that changing the sensors had much effect on the fridge performance, but who knows.

We have been on our fall trip for 5 days now, and while the temperatures have been cooler, the difference in the fridge performance is astounding. The bottle of root beer we had in the fridge door is frozen solid. According to the sensors (which have not been calibrated, the fridge is about 29-30 degrees and the freezer is -3 degrees (fahrenheit). I cut the fridge back to "3", a few of hours ago, and we are now at 35 degrees. i am going to keep on monitoring it, but obviously something has changed. we are currently running on electric but the performance on propane is also noticeably improved.

[fudge_brownie]

I found the lower door gasket had come loose, not easily noticed unless you are looking for a problem.

Leon
I did not calibrate the sensor but from what I did measure it was quite accurate. I use one for outside temps as well.

[LeonW]

We set control back to 3, but it is only 28 degrees in the fridge this morning - everything frozen! So I switched it back to propane to see what happens there. Maybe I pulled a wire loose from the fridge when I moved the thermistor. But this tells me that it is possible to make the fridge cold, even when it is 80 degrees out during the day. When we return I am going to pull the fridge and make sure that I didn't pull out a wire, perhaps add a bit of insulation, and see where we go from there.

[PGDriver]

Leon have you ever thought about replacing the stock thermistor with an adjustable one like this.
http://www.snip-the-tip.com/RM8XXX.html
Cheers
Doug

[thoer]

This makes me again wonder why this type fridge is not offered with temperature controlled cooling.

With the wealth of inexpensive computer control chips now available, it would seem that it could be accomplished without hugely increasing the costs. With LP the flame would need to be adjusted and with AC/DC the current controlled, both of which seem comparatively relatively easy - especially with AC/DC. LP would need a electronically controlled flow valve, perhaps those are still quite expensive?

But I would think many people would be more than willing to spend more and have less need of constant monitoring. Early morning coffee drinking postulating - maybe I am missing some large reason?

[escape artist]

Originally Posted by thoer

This makes me again wonder why this type fridge is not offered with temperature controlled cooling.

With the wealth of inexpensive computer control chips now available, it would seem that it could be accomplished without hugely increasing the costs. With LP the flame would need to be adjusted and with AC/DC the current controlled, both of which seem comparatively relatively easy - especially with AC/DC. LP would need a electronically controlled flow valve, perhaps those are still quite expensive?

But I would think many people would be more than willing to spend more and have less need of constant monitoring. Early morning coffee drinking postulating - maybe I am missing some large reason?

Hi: thoer... Basically component Mfg's seem lazy and slow to change. The door on our RML8551 was the same model as the ones designed to be reversed L to R even though they couldn't be!!! That's when I found that, while using the MaxxFan on exhaust, so much cold air was being sucked out of the fridge box. At the same time that air was being replaced with hot incoming air up the drain tube. Alf
escape artist N.S. of Lake Erie

[txruby77]

We have a 2016 Escape 21 with the RMD8555 fridge. I live in central Texas with temps in the high 90-100's. We had intermittant issues of it not staying cold, getting up to 50degrees at times, w/ice cream melting in the freezer. This was with it on propane or AC. Reace tried to troubleshoot over the phone, but still had issue.
We took it to a Dometic service dealer and they replaced the circuit board and installed a new fan switch on the outside. (covered by warranty). They said Dometic told them this is a known problem with this model. Right now, the fridge temperature is about 38degrees, on AC. We are going on an extended roadtrip and hopefully this will solve the issue.

[rbryan4]

Originally Posted by txruby77

We took it to a Dometic service dealer and they replaced the circuit board and installed a new fan switch on the outside. (covered by warranty). They said Dometic told them this is a known problem with this model.

I've no doubt that Dometic told them that, but I also have no doubt that Dometic often doesn't know what they're talking about. A simple search of all the ongoing fridge threads will give you the sense that Dometic is a company where one hand doesn't know what the other hand is doing.

Your fridge performance right now is similar to ours with the same model. Hopefully you're now good to go.

[Kountrykamper]

Originally Posted by fudge_brownie

I found the lower door gasket had come loose, not easily noticed unless you are looking for a problem.

Leon
I did not calibrate the sensor but from what I did measure it was quite accurate. I use one for outside temps as well.

These sensors are very cool. Received mine today. Thanks for the recommendation.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[ReagentGrade]

Agreed! I lucked out and got one on a daily deal for $38. I'm impressed. It works great.

I have it sitting in my living room right now. When I pull up the App, it's easy to see when the AC ran. The temp and humidity both decline pretty fast and gradually drift back up when it stops.