2nd Generation refrigerator issues

[rubicon327]

Originally Posted by cpaharley2008

Reace came over and surmised that the issue is not the refer blowing out but warm air being sucked into the refer. There is no cup like the older model that prevents this. If the flame was blown out there would be a fault light, similar to the water heater that flame out occurred. Since that did not happen then the heat is being sucked into the refer through that vent that is open to the outside. He suggests cracking a window or plugging the vent somehow....

Jim: The dynamics of this are interesting. I'm not surprised to hear that Reace doesn't think the flame is blowing out when traveling. When doing some maintenance on our older RM2510 it took a very forceful blow of air right on the burner (with cover off) to blow the flame out and it would relight instantly. Unless there is some serious turbulence in the refrigerator compartment the flame should not blow out. Good heat rejection via the chimney effect that must be maintained across the condenser/absorber is another matter. If the rooftop vent wasn't just a cheap piece of plastic and was designed with some wind tunnel testing it could be shaped to create a low pressure zone and positive suction of air from bottom vent to top when towing. That is my guess as to the problem more than anything. Just a thought but have you tried to override and run the exterior fridge fan while towing?

Originally Posted by cpaharley2008

Yes, the condensation or defrost drain tube has a special end that is supposed to hold water and prevent air escaping, but with all this heat the water is evaporating quickly thus the tube is open thus allowing warm air to enter the refrigerator. That is his opinion and he suggests that a crack in the window will slow down the vacuum effect while towing. Otherwise the performance is great sitting still, even in 100+ temperatures.

Does the end look something like this? Not sure how this would work exactly but it is a Dometic product made to used on the end of a refrigerator drain line.
www.amazon.com/dp/B008RO9DZE/ref=cm_sw_su_dp

[elongest]

For the end of the drain hose I have been looking for a small duckbill valve. It is what the Hepvo valve uses. Then there would be no need for a trap and water. The small ones I have found so far are used in home brewing, milking machines and breast pumps. I ordered a home brewing valve, it looked like it was made for a 3/8" line but it was too stiff. I will continue to search for one.
Eddie

[cpaharley2008]

Originally Posted by rubicon327

Jim: The dynamics of this are interesting. I'm not surprised to hear that Reace doesn't think the flame is blowing out when traveling. When doing some maintenance on our older RM2510 it took a very forceful blow of air right on the burner (with cover off) to blow the flame out and it would relight instantly. Unless there is some serious turbulence in the refrigerator compartment the flame should not blow out. Good heat rejection via the chimney effect that must be maintained across the condenser/absorber is another matter. If the rooftop vent wasn't just a cheap piece of plastic and was designed with some wind tunnel testing it could be shaped to create a low pressure zone and positive suction of air from bottom vent to top when towing. That is my guess as to the problem more than anything. Just a thought but have you tried to override and run the exterior fridge fan while towing?



Does the end look something like this? Not sure how this would work exactly but it is a Dometic product made to used on the end of a refrigerator drain line.
www.amazon.com/dp/B008RO9DZE/ref=cm_sw_su_dp

Yes that is the end of the tube

[cpaharley2008]

Another forum member suggested a Hepvo valve set up, so I took the rally ballon and made one...thanks Wetzk...

[cpaharley2008]

photo attached

[Kountrykamper]

They have balloons? Dang.

Good idea

[Starbrightsteve]

So, all the cold air in the refrigerator is sucked out through this 3/8 id tube? And, since cold air is being removed from the fridge, warm air is leaking into the fridge. Possibly because the fridge door seals leak. Is that the theory proposed by some folks as to why the fridge gets warm when driving. Just asking? Curious?

[gocamp]

Wondering the exact question here too Steve

[Kountrykamper]

That has been a theory for a while and the reason for keeping water in the 8000 series drain cup. I don't think anyone knows if it sucks the cold out or pushes the heat in. The new models have a drain hole on the inside air could come in too.

[fudge_brownie]

That is one theory for sure. Another theory is that the flame for the refrigerator is getting blown out from any of a number of sources: upper (roof) vent pulling too much air out the top, lower vent allowing too much air and or turbulence near that flame, or too much air leakage around the perimeter of the refrigerator creating drafts that extinguish the flame.

A whole series of theories have covered the mechanicals: starting with the propane regulator, impure or contaminated propane causing orifice blockages, improper adjustment of the piezo lighter, location of the temperature sensor inside the refrigerator, leakage of air out of the wire opening for the temperature sensor, leakage of air around the door seals and latches of the refrigerator.

Then there are the human foibles that get coverage: opening the door to much or opening the door when it is hot outside, not letting the refrigerator cool down enough before loading or putting warm items into the refrigerator, not using computer fans for circulation or special made curtains that reduce cold loss when opening the door.

The litany just goes on and on. What makes it annoying is it is not consistent. There are many units that perform perfectly.

In my opinion it appears that there are several issues going on at once, we do not or can not perform just one fix and then test it.

I think some minor construction aberration could be a cause. Something like, some units come out of assembly with the refrigerator roof vent in a slightly different spot or at a slightly different angle and the wind currents and drafts are as a result different. Another possibility, some units have a unknown opening or are more air tight so drafts or vacuums occur inside the trailer. Third, the draft box at the rear of the refrigerator is constructed differently from unit to unit and this results in air currents that extinguish the flame. These are all possibilities, I do not want to defend them. In my situation, it was not the fault of the refrigerator, I have had both models (single door and double door) in my Escape and in both cases the refrigerator will not cool consistently while driving. It has to be a design or construction issue with the trailer.

It seems some of the fixes have worked for some people but no fixes have worked for others. Results seem inconsistent, for several trips everything is working fine and then suddenly the temperature sensors inside the refrigerator are climbing while travelling.

[azjack]

It has been working quite well. I planned on the trip up here to test the filter on the vent but temp was such that we didn't see any really hot temps and the temps were 0 to 10 in the freezer and 30 to 38 in the fridge. I have added a stove vent filter but I don't know if it will help at 100. If someone wants to add a stove vent metal filter, I have spares and a few tie wraps, stop by space 75 and pick one up.
Jack

[cpaharley2008]

There is no flame out involved. If it were you would have a fault light on the refrigerator, similar to the water heater, indicating a problem. If the refer does not light after 3 attempts, it shuts down and there is the fault light. I have never experienced the fault light on any of my Dometic units. To prove this, turn off your gas and watch what happens to the refrigerator.
The issue is warm air is being introduced thru the condensate drain hose, causing the temperature to rise. It only happens while being in motion, not camping at a standstill.

[sunrisetrucker]

Originally Posted by cpaharley2008

camping at a standstill.

Camping at a standstill is the only kind I do.

[padlin]

Unless it gets blown out, then relights itself in less then the time it takes to generate the alarm. Over and over and ...

[rubicon327]

Originally Posted by fudge_brownie

That is one theory for sure. Another theory is that the flame for the refrigerator is getting blown out from any of a number of sources: upper (roof) vent pulling too much air out the top, lower vent allowing too much air and or turbulence near that flame, or too much air leakage around the perimeter of the refrigerator creating drafts that extinguish the flame.

A whole series of theories have covered the mechanicals: starting with the propane regulator, impure or contaminated propane causing orifice blockages, improper adjustment of the piezo lighter, location of the temperature sensor inside the refrigerator, leakage of air out of the wire opening for the temperature sensor, leakage of air around the door seals and latches of the refrigerator.

I agree that it could be a combination of items leading to the unsatisfactory operation, but I don't think we are giving enough attention to the actual design and inherent limitations of an absorption refrigerator. It is unlikely the flame is blowing out. What is likely in my opinion is a refrigerator that is "working" just not working efficiently. If the ambient temperature is very high and/or airflow is inadequate across the condenser the ammonia vapor cannot condense into a liquid in enough volume to move to the evaporator coil in the fridge and absorb the required heat. The uncondensed ammonia would then travel back to the tank/absorber vessel via a compensation tube. The fridge is on, but cooling will be severely compromised.

https://m.youtube.com/watch?v=34K61ECbGD4

[Kountrykamper]

I agree it is a combination of items and it's is not just air going in the drain tube. On the 8000 series I made a trap in the drain line and that helped but still had problems. Air was not going up the drain tube with a trap in it.

I do think it has something to do with airflow. Possibly that air gets force up the chimney while traveling and causing the burner to cool down reducing cooling. Restricting airflow with a metal filter seem to help this for us most of the time. Possibly a vacuum in the trailer, who knows.

But then there are those times when nothing made sense. On a trip out west once ours worked fine for 6 days of traveling. After the 7th day of just camping one day it just quit cooling. After transferring everything to a cooler restarting the fridge and letting it cool down over night it worked fine the remainder of the trip.

I do think sometime we expect to much out of these things and do things like opening the door or adding warm food and expect them to cool. Also we have much better thermometers and equipment to measure and track the temps than we did in the past. Maybe ignorance really is bliss.

[Dave Walter]

Originally Posted by Kountrykamper

...Also we have much better thermometers and equipment to measure and track the temps than we did in the past. Maybe ignorance really is bliss.

Confirmation of your theory. I have never checked the temperature inside of my fridge and it has performed flawlessly since I got it.

[elongest]

I agree with others. I have a fairly new to me trailer and was made aware of the OTR frig. cooling issues. I am working my way through the older fixes and with the exception of the fan temp. sensor. (static improvement) Most all fixes have to do with air flow during travel.
The top exhaust is by far the best exhaust. On all other trailers I have dealt with the exhaust is usually on a flat smooth roof. On my trailer the exhaust port is set on a platform that does not conform to the contour of the trailer. It appears turbulent air is being forced up under the front of the exhaust stack. On my list of things to do is try to keep this air from being forced up under the exhaust cover. Trying to deflect the turbulent air without creating an excessive vacuum in the rear frig. service compartment will be the challenge. I don't think this has been addressed yet.
Eddie

[float5]

Originally Posted by elongest

I agree with others. I have a fairly new to me trailer and was made aware of the OTR frig. cooling issues. I am working my way through the older fixes and with the exception of the fan temp. sensor. (static improvement) Most all fixes have to do with air flow during travel.
The top exhaust is by far the best exhaust. On all other trailers I have dealt with the exhaust is usually on a flat smooth roof. On my trailer the exhaust port is set on a platform that does not conform to the contour of the trailer. It appears turbulent air is being forced up under the front of the exhaust stack. On my list of things to do is try to keep this air from being forced up under the exhaust cover. Trying to deflect the turbulent air without creating an excessive vacuum in the rear frig. service compartment will be the challenge. I don't think this has been addressed yet.
Eddie

Don't know what refrigerator you have but many people think that there is only old vs. new. There have been several refrigerators in Escapes. Ours (RMD8555 I believe) is two-door, separate door for the freezer, not the new generation and not the old ones that had all of the problems, and works well so far for many of us.

[elongest]

I was speaking of my trailer frig. issues. My trailer is on frig #2 currently a RMD 8555 two door is installed. I was told when I bought it, it won't cool on the road on gas and it won't. I went over another E-21 almost exactly like mine last weekend with the same two door frig. and they have no issues with their frig. Their trailer had some of the modifications suggested on the forum but nothing that I have not already done. I know the frig. can work just got to figure out why mine does not work OTR with gas, but I do not seem to be alone with this issue. This really does not need to be addressed on a second gen. thread.
Eddie