R-pod Owners Forum : Dead Dometic RM8501 https://www.rpod-owners.com/ This is an XML content feed of; R-pod Owners Forum : Podmods, Maintenance, Tips and Tricks : Dead Dometic RM8501 Copyright (c) 2006-2009 Web Wiz Forums - All Rights Reserved. Sat, 30 May 2026 13:54:25 +0000 Sun, 20 Aug 2017 16:31:21 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 9.64 360 https://www.rpod-owners.com/RSS_post_feed.asp?TID=10439 R-pod Owners Forum https://www.rpod-owners.com/forum_images/web_wiz_forums.png https://www.rpod-owners.com/ Dead Dometic RM8501 : I installed a 3" computer... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98244#98244 Author: spydie
Subject: 10439
Posted: 20 Aug 2017 at 4:31pm

I installed a 3" computer fan at the top vent and it significantly helped with the cooling.  So I took out that stupid 3" fan Dometic or FR put on the bottom of the coils that only turns on when it's way past time you should have some cooling help, and I then mounted it next to my first 3" fan.  Not sure two fans do much more than 1 fan, but I figured, "why not?".  each fan draws about 0.15-0.16 amps so I have better cooling for about 3/10s of an amp and I put a switch on them so I can manually turn it off in colder weather when I don't need the help.  Forest River has never replied to the dealer's complaint yet.  It's still several degrees more efficient on electricity than it is on LP but I guess I'll just have to live with that.  I'm able to keep it under 42 degrees now (just barely) in 99 degree weather in the middle of the day.  It gets down to 32-34 degrees at night (depending whether it's on electricity or LP).]]> Sun, 20 Aug 2017 16:31:21 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98244#98244 Dead Dometic RM8501 : I predict that within 5 years... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98161#98161 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 10:57pm

I predict that within 5 years we'll be using Thermal Electric Generators (TEGs) to produce the 12 volts we need to run our swing-compressor refrigerators and the power will be produced by an LP flame that we now use for our absorption refrigerators.  We've had TEGs in the military and commercial world for decades and they are just now starting to get to be more efficient and cost affordable.  I think those would be the salvation for the obsolete absorption refrigerator.  And they might even be able to extend dry camping times if we can get enough out of them to run the refrigerators and keep the batteries charged.  Kinda like a solar panel that runs on an LP flame.  But of course then we'll have to carry more LP! LOL . Nothing is free]]> Thu, 17 Aug 2017 22:57:26 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98161#98161 Dead Dometic RM8501 : Ha ha. Yes. I just tested my Engel... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98160#98160 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 10:23pm

Ha ha. Yes. I just tested my Engel chest freezer/refer on an 80 watt solar panel and 75 amp/hr deep cycle battery and it can easily keep up. The Engel draws only about 30-40 watts or about 1.7 average amps per hour. Swing compressors draw little current. I used a built in one in my last RV for almost four years on about 200 amp/hr of batteries (three 12 v batteries ) and we dry camped all the time. Spent six weeks going to Alaska and only spent three nights in campgrounds. It's possible to run a 12 v compressor refrigerator in place of the dometic with only slightly more battery power and a solar panel really helps. ]]> Thu, 17 Aug 2017 22:23:14 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98160#98160 Dead Dometic RM8501 : Originally posted by spydieIn... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98159#98159 Author: pgoelz
Subject: 10439
Posted: 17 Aug 2017 at 10:13pm

Originally posted by spydie

In my opinion, which isn't worth much, I think the absorption refrigerator is antiquated and needs to be abolished.  They've never been efficient in an RV if you travel in warm/hot weather.  They were developed for household use and I'm sure they are fine in that capacity, but even then they were replaced with more efficient compressor refrigerators.  So what did we do?  We took something that was replaced with something better for the household, and tried to put them into RVs where the OAT has a major affect on them.
With you there ;)  But is there anything on the horizon that is capable of replacing the absorption fridge?  Ie., a refrigerator that runs with minimal to no electric power?  Something that does not use electrical power for the cooling process itself?  Something that does not require 200-400W of solar and golf cart batteries?  

Paul
]]> Thu, 17 Aug 2017 22:13:31 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98159#98159 Dead Dometic RM8501 : At 80-85 degrees it may work ok.... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98157#98157 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 9:19pm

At 80-85 degrees it may work ok. We are talking 95-100 temps here in the great SW. Dometic will only accept temperature measurements via water test. A glass of water measured with a bulb thermometer. My temps were carefully measured the only acceptable way and monitored by dometic. 34-36 degrees at night when it's less than 70s degrees outside and climbs into high 50s and low 60s during the day in 95-100 degree heat . That's totally unacceptable for camping. 42 degrees is the least acceptable for dairy products. ]]> Thu, 17 Aug 2017 21:19:32 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98157#98157 Dead Dometic RM8501 : Sooo, after all this...What... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98155#98155 Author: fwunder
Subject: 10439
Posted: 17 Aug 2017 at 9:10pm

Sooo, after all this...

What is the consensus for "proper" or "adequate" cooling? Speaking for myself and measuring carefully with "normally" full freezer and refrigerator areas, I have no problem maintaining 31-36 degrees in fridge and 10-20 in freezer. Using digital (Accurite), analog and Thermopen, I've been doing some testing the last few days in my driveway. Full sun and 80-85 degrees, no AC running (so it's 90+ in pod). I have tested both AC and propane. To simulate normal packing, I have several prefrozen freezer packs in freezer portion and two six-packs of 16 oz. soda in fridge.

BTW, an evaporator (fin) fan is a total waste of money in the fridge. I'll write more about that later. Suffice to say fan motors give off more heat than the benefit of moving air *in* the fridge.

Just curious if anyone has any one else has carefully measured fridge/freezer temps in their rPod?

fred




]]> Thu, 17 Aug 2017 21:10:12 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98155#98155 Dead Dometic RM8501 : Just picked up my Rpod at the... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98137#98137 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 5:21pm

Just picked up my Rpod at the dealer.  Dometic says it's not mounted properly and it's all Forest Rivers fault.  It doesn't have enough space around it so it can breathe and cool properly (the insulation is packed way too tight and the sides of the Dometic get hot).  Dometic looked at 15 pictures the dealer sent them of the installation and they said there's no way it can cool properly in there, there's no space around it.  All the information has been sent by the dealer to Forest River to see what their reaction is.  Probably won't hear from them, but if we do, they won't take any blame with "we've been building them like that for years and nobody else has complained."  (yah, right!).  Buyer beware.  Anybody want to buy a real nice 2018 rpod 176?  Cheap!  NEVER USED FOR CAMPING.  LOL]]> Thu, 17 Aug 2017 17:21:33 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98137#98137 Dead Dometic RM8501 : In my opinion, which isn't... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98131#98131 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 3:35pm

In my opinion, which isn't worth much, I think the absorption refrigerator is antiquated and needs to be abolished.  They've never been efficient in an RV if you travel in warm/hot weather.  They were developed for household use and I'm sure they are fine in that capacity, but even then they were replaced with more efficient compressor refrigerators.  So what did we do?  We took something that was replaced with something better for the household, and tried to put them into RVs where the OAT has a major affect on them.

I have heard from a lot of people on different forums about the lack of the Dometic working properly in the Rpod, and there's no correlation between which models it's in.  There's a small chance that Forest River needs to re-design the mounting area.  The only people that aren't complaining much are the ones that live in cooler climates than the HOT southwest and never travel to hot climates in the summer, so they don't really know how bad an absorption refrigerator is.  Other people just give up and carry an ice chest or, like me, a real compressor chest/freezer along for the campouts.  Of course the Rpods are built in Indiana and Washington... they don't know what hot weather is and have never researched it so they have no idea that their design, if improved, could solve the problem of the inefficient Dometic.  And they don't care.
]]> Thu, 17 Aug 2017 15:35:56 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98131#98131 Dead Dometic RM8501 : Originally posted by spydieThey... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98129#98129 Author: pgoelz
Subject: 10439
Posted: 17 Aug 2017 at 3:26pm

Originally posted by spydie

They told me that when they had it on the bench they took the jet out and cleaned it in alcohol.
Well, so much for my best shot ;)  If the jet is clean and the pressure is within spec, not sure what else it could be.  

Do we know for sure that simply swishing it in alcohol is sufficient?  When I cleaned mine it was alcohol in an ultrasonic cleaner, which might have been more thorough.  

Mounted it incorrectly?  How is that even possible?  That said, when I was talking to Dometic, they raised the possibility it was not level in the trailer.  Again, not sure how THAT is possible either so I guess they are just taking pot shots.  

Paul
]]> Thu, 17 Aug 2017 15:26:35 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98129#98129 Dead Dometic RM8501 : OK, just got back from the RV... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98127#98127 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 3:15pm

OK, just got back from the RV dealer.  They've been working with Dometic for the last week (again) and Dometic now says it's a Forest River problem.  Forest River did not mount the Dometic correctly.  He is now working with Forest River (sent them 15 pictures) and waiting to hear from them.  We all know that FR isn't going to take ownership of the problem any more than Dometic will unless there's a class-action lawsuit that forces them to recall the R-pods and mount the Dometic differently.  So I'm pretty sure that after the dealer has it another week, they'll tell me it's my problem because nobody wants to fix it.  My options at that point are 1. only camp in colder weather so the refer works OK or 2. replace the Dometic with a real refrigerator like the Engel I built into my last RV or 3. trade it off for another brand that may or many not work better.

By the way, they pressure tested the LP both in the Rpod and on the bench to make sure it was OK in both settings.
]]> Thu, 17 Aug 2017 15:15:44 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98127#98127 Dead Dometic RM8501 : They told me that when they had... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98126#98126 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 2:55pm

They told me that when they had it on the bench they took the jet out and cleaned it in alcohol.]]> Thu, 17 Aug 2017 14:55:13 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98126#98126 Dead Dometic RM8501 : In the mean time, it is not hard... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98125#98125 Author: pgoelz
Subject: 10439
Posted: 17 Aug 2017 at 2:52pm

In the mean time, it is not hard to clean the gas jet.  If the pressure is OK in the trailer, a clogged gas jet would produce your exact symptoms (assuming it cools OK on AC power).  If their bench test pressure is higher, it could overcome a clogged gas jet and produce adequate cooling.  It doesn't seem linear.... below a certain flame size, you get zero cooling even though there is a nice blue flame.  That was my issue earlier in this thread.  

Look at me.... two weeks ago I didn't know much of anything about how these things work.  Its amazing what a little head scratching and research can teach you ;)  Especially with an engineering background.  

Paul
]]> Thu, 17 Aug 2017 14:52:55 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98125#98125 Dead Dometic RM8501 : That's a good question Paul.... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98122#98122 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 1:03pm

That's a good question Paul.  I ask them]]> Thu, 17 Aug 2017 13:03:01 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98122#98122 Dead Dometic RM8501 : Originally posted by spydieI... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98121#98121 Author: pgoelz
Subject: 10439
Posted: 17 Aug 2017 at 12:32pm

Originally posted by spydie

I got my pod back after two weeks with the dealer and they couldn't fix it.  Dometic said they could only test it if it was OUT of the pod, on a test bench.  So they did that and it worked fine inside.  Put it back in the Pod and it still wouldn't cool properly on LP.  I took it home and called Dometic and said I wanted a new refer.  They said it has a 2-year warranty and that the only the dealer could request a warranty replacement, so I took it back to the dealer and they are now trying to get a replacement.
Do you know if they compared the gas pressure on their bench to what it is at the refer in your trailer?  That would affect the size of the flame and could explain the lack of cooling in the RV.  

Paul
]]> Thu, 17 Aug 2017 12:32:32 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98121#98121 Dead Dometic RM8501 : I got my pod back after two weeks... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98114#98114 Author: spydie
Subject: 10439
Posted: 17 Aug 2017 at 8:01am

I got my pod back after two weeks with the dealer and they couldn't fix it.  Dometic said they could only test it if it was OUT of the pod, on a test bench.  So they did that and it worked fine inside.  Put it back in the Pod and it still wouldn't cool properly on LP.  I took it home and called Dometic and said I wanted a new refer.  They said it has a 2-year warranty and that the only the dealer could request a warranty replacement, so I took it back to the dealer and they are now trying to get a replacement.]]> Thu, 17 Aug 2017 08:01:24 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98114#98114 Dead Dometic RM8501 : Originally posted by mjlrpodWell,... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98112#98112 Author: pgoelz
Subject: 10439
Posted: 17 Aug 2017 at 6:06am

Originally posted by mjlrpod

Well, 3 degrees is equal to 3 3/4 inches from side to side of the pod. So the door side can be 3 3/4 inches higher or lower than the hook up side. Incase you wern't sure. 
Oh, I am VERY sure.  I fly model helicopters and I have a digital pitch gauge so I measured the pod when it was attached to the TV on the driveway ;)  As it sat, it was around 2.2 degrees off level.  Since that is the most off level I have ever exposed it to with the refer running, hopefully I didn't do any damage at all. And obviously I didn't kill it.... the problem was a partially plugged burner.    

In my research, I found a company that makes an aftermarket boiler high temperature shutdown unit.  Costs about $180 and might be well worth it.  Shame on Dometic for not including that feature in the first place even as an option).  Yes, I'm still mad.  

Paul
]]> Thu, 17 Aug 2017 06:06:25 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98112#98112 Dead Dometic RM8501 : I never really use mine. My wife... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98111#98111 Author: sal
Subject: 10439
Posted: 17 Aug 2017 at 1:21am

I never really use mine. My wife would like some drawers. I just may take out my refrigerator,151, and build something there. For sure if it breaks.
Sal]]> Thu, 17 Aug 2017 01:21:01 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=98111#98111 Dead Dometic RM8501 : Originally posted by pgoelzIs... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97683#97683 Author: spydie
Subject: 10439
Posted: 08 Aug 2017 at 1:13pm

Originally posted by pgoelz

Is there an online source for that service manual?  It is definitely NOT what I have.... mine claims to be an RM8xxx service manual, but I didn't see anything about a new cooling unit design.  And yes, ours is round, not square.  

Ya know, this just makes me even more angry!  After all the trauma last week while camping with our dead refrigerator and on the phone with Dometic, they still told me the max tilt before PERMANENT damage was 3 degrees!  And I told them what model and year my fridge was!  Their position was that if I had operated our three year old RM8501L more than 3 degrees off level, I had destroyed the cooling unit and they would do nothing for me.  They also swore up and down this information was in the manual.  When I pointed out that in fact it WAS NOT, they backed down from that claim but still said it was my fault for operating off level.  It was a very carefully worded statement that I was told was "what they were supposed to tell" people like me.  I could not even get a word in edgewise.  

Of course, as it turned out (earlier in this thread) I measured our driveway and had NOT operated more than 3 degrees off level and it turned out the problem was NOT the cooling unit.  But the massive mis-information and lack of information coming out of Dometic boggles my mind.  

Sorry... even though we had a happy ending when we got home and could carefully troubleshoot on shore power, I am still reeling from the experience after spending our camping time preparing for a >$1000 expenditure to fix the refer.  Dometic should be ASHAMED of themselves for putting us though that.  

Paul

Paul, I posted this yesterday.  It's the service manual Dometic and my RV service company and I use:
https://www.dropbox.com/s/32i0fssts7yrw61/dometic-service-manual%20copy.pdf?dl=0
]]> Tue, 08 Aug 2017 13:13:25 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97683#97683 Dead Dometic RM8501 : Well, 3 degrees is equal to 3... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97681#97681 Author: mjlrpod
Subject: 10439
Posted: 08 Aug 2017 at 1:09pm

Well, 3 degrees is equal to 3 3/4 inches from side to side of the pod. So the door side can be 3 3/4 inches higher or lower than the hook up side. Incase you wern't sure. ]]> Tue, 08 Aug 2017 13:09:07 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97681#97681 Dead Dometic RM8501 : Is there an online source for... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97679#97679 Author: pgoelz
Subject: 10439
Posted: 08 Aug 2017 at 12:57pm

Is there an online source for that service manual?  It is definitely NOT what I have.... mine claims to be an RM8xxx service manual, but I didn't see anything about a new cooling unit design.  And yes, ours is round, not square.  

Ya know, this just makes me even more angry!  After all the trauma last week while camping with our dead refrigerator and on the phone with Dometic, they still told me the max tilt before PERMANENT damage was 3 degrees!  And I told them what model and year my fridge was!  Their position was that if I had operated our three year old RM8501L more than 3 degrees off level, I had destroyed the cooling unit and they would do nothing for me.  They also swore up and down this information was in the manual.  When I pointed out that in fact it WAS NOT, they backed down from that claim but still said it was my fault for operating off level.  It was a very carefully worded statement that I was told was "what they were supposed to tell" people like me.  I could not even get a word in edgewise.  

Of course, as it turned out (earlier in this thread) I measured our driveway and had NOT operated more than 3 degrees off level and it turned out the problem was NOT the cooling unit.  But the massive mis-information and lack of information coming out of Dometic boggles my mind.  

Sorry... even though we had a happy ending when we got home and could carefully troubleshoot on shore power, I am still reeling from the experience after spending our camping time preparing for a >$1000 expenditure to fix the refer.  Dometic should be ASHAMED of themselves for putting us though that.  

Paul
]]> Tue, 08 Aug 2017 12:57:22 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97679#97679 Dead Dometic RM8501 : Still reading the latest service... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97676#97676 Author: spydie
Subject: 10439
Posted: 08 Aug 2017 at 12:36pm

Still reading the latest service manual and their new design is both interesting and a welcome change:

In recent years Dometic has engineered a newtype of cooling unit that utilizes an improvedsiphon pump tube design which drasticallyreduces the possibility of permanent damage tothe coils if operated in an out-of-level condition,or too much heat is generated at the boilersection. As we can see from this drawing, thesiphon pump tube is enclosed in the designand is surrounded by a weak ammonia solution,which will protect the pump tube from abnor-mally over-heating. This type of unit; however,does not eliminate the need for proper leveling.The unit still requires gravitational flow toprovide the proper cooling process, and ifleveling is outside the necessary limits, coolingwill dramatically slow down or stop completely.The cooling coils are not normally damaged inthis fashion and once proper leveling is main-tained, the cooling process will resume.

Spirit or bubble levels are no longer beingsupplied with the new style refrigerators as theRV or vehicle only needs to be leveled so it iscomfortable to live in, with no noticeable slopingof the floor or walls. For diagnosis, the newstyle cooling units that incorporate theprotection boiler system, can be differentiatedfrom the older style coils by the shape anddesign of the outer boiler box cover on the rearof the cooling unit. These units will incorporatea circular metal cover,

while the older style utilizes a squareshaped enclosure. We will discuss diagnosisand troubleshooting of these units in moredetail later in the program.

]]> Tue, 08 Aug 2017 12:36:51 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97676#97676 Dead Dometic RM8501 : Good guess.... better than any... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97675#97675 Author: pgoelz
Subject: 10439
Posted: 08 Aug 2017 at 12:24pm

Good guess.... better than any of my guesses ;)  Not sure though.  

Paul
]]> Tue, 08 Aug 2017 12:24:37 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97675#97675 Dead Dometic RM8501 : Is it a port to check the gas... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97672#97672 Author: StephenH
Subject: 10439
Posted: 08 Aug 2017 at 11:08am

Is it a port to check the gas pressure?]]> Tue, 08 Aug 2017 11:08:20 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97672#97672 Dead Dometic RM8501 : BTW, does anyone know what the... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97657#97657 Author: pgoelz
Subject: 10439
Posted: 08 Aug 2017 at 6:50am

BTW, does anyone know what the brass thing is in the incoming propane line in the refer compartment just ahead of the gas valve?  It is a solid brass block with a hex screw cap on the side.  Is it a regulator?  If so, does it require maintenance?  Because it is not officially part of the refer, it is not in the service manual.  Just curious.  

Paul
]]> Tue, 08 Aug 2017 06:50:40 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97657#97657 Dead Dometic RM8501 : I'm guessing it's... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97636#97636 Author: fwunder
Subject: 10439
Posted: 07 Aug 2017 at 4:19pm

I'm guessing it's easier to specify a delta of 30-40 degrees with thermoelectric (thermopile) coolers because they are almost always surround by ambient air. 

An RV installation of the absorption fridge can vary wildly as well as environment surrounding fridge. In warm or hot weather, I will run the pod AC in my driveway to noticeably make a difference in fridge performance before loading (front side considerably cooler than back side).

My ideal arrangement would be a NovaKool compressor fridge only and a Dometic Portable setup as a chest freezer. More cold beer, more solid ice cream!

fred
]]> Mon, 07 Aug 2017 16:19:50 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97636#97636 Dead Dometic RM8501 : Originally posted by spydieTell... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97633#97633 Author: pgoelz
Subject: 10439
Posted: 07 Aug 2017 at 4:00pm

Originally posted by spydie

Tell me what a delta measurement is please
A "delta" measurement is the difference between two values.  Delta = value 1 minus value 2.  For example, put one thermocouple in free air outside the trailer and the other in the refrigerator.  The DIFFERENCE between the internal and external temperatures is the "delta" temperature.  

You will find some refrigerators (especially thermopile refrigerators like simple electric coolers) have a specified minimum delta temperature, which would be a measure of their ability to cool.  I think my Coleman electric cooler is spec'd at something like 30 or 40 degrees.... the inside will be 30-40 degrees cooler than the outside ambient.  

I'm sure our Dometics have a minimum delta spec but I doubt Dommetic will share it with us.  Much easier to claim proper operation when all specs are as vague as possible ;)  

Paul
]]> Mon, 07 Aug 2017 16:00:48 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97633#97633 Dead Dometic RM8501 : Tell me what a delta measurement... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97631#97631 Author: spydie
Subject: 10439
Posted: 07 Aug 2017 at 3:37pm

Tell me what a delta measurement is please]]> Mon, 07 Aug 2017 15:37:35 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97631#97631 Dead Dometic RM8501 : Originally posted by spydieCorrect... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97630#97630 Author: pgoelz
Subject: 10439
Posted: 07 Aug 2017 at 3:31pm

Originally posted by spydie

Correct me if I'm wrong, but Dometic wouldn't accept my remote refrigerator sensor (an outdoor thermometer) even though I checked the calibration with a bulb thermometer.  They claim the only reading they will accept from the servicing dealer is the 'water glass' test.  I don't know what kind of sensor you are using nor how accurate it is, nor where you have it placed (that makes a big difference), but I'd like to know more about it, please?
I'm just using a $20 dual thermocouple meter I bought on Ebay to measure model helicopter motor temperatures.  It seems pretty accurate... within a degree at worst.  Since it has two thermocouple inputs (and came with two thermocouples) it can even make delta measurements if you want.  

I placed a single thermocouple in free air between the rods of the lower shelf.  

Final stabilized measurements at 74 degrees ambient and at the middle setting after a couple hours operation are:

PROPANE = 37 degrees
120VAC = 40 degrees

I'm not sure I could hear the flame from a couple feet away but I can definitely hear it now with my head near the lower vent.  

Paul

]]> Mon, 07 Aug 2017 15:31:20 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97630#97630 Dead Dometic RM8501 : Correct me if I'm wrong,... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97624#97624 Author: spydie
Subject: 10439
Posted: 07 Aug 2017 at 2:52pm

Correct me if I'm wrong, but Dometic wouldn't accept my remote refrigerator sensor (an outdoor thermometer) even though I checked the calibration with a bulb thermometer.  They claim the only reading they will accept from the servicing dealer is the 'water glass' test.  I don't know what kind of sensor you are using nor how accurate it is, nor where you have it placed (that makes a big difference), but I'd like to know more about it, please?]]> Mon, 07 Aug 2017 14:52:37 +0000 https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97624#97624 Dead Dometic RM8501 : I read somewhere that if you are... https://www.rpod-owners.com/forum_posts.asp?TID=10439&PID=97623#97623 Author: pgoelz
Subject: 10439
Posted: 07 Aug 2017 at 2:11pm

I read somewhere that if you are using a remote reading meter to measure internal temperature, the water glass is not required.  They simply want to ensure that the temperature is the actual internal temperature PRIOR to opening the door and the glass of water slows down any temperature changes when the door is opened.  

I think I'll give it a rest for now.  After cleaning the orifice, it has gone from ZERO cooling on gas to frost covered freezer fins (freezer compartment removed) and a steady 41 degrees on middle setting (36 degrees on middle + 1 setting) at a 74 degree external ambient.  

My interpretation is that the absorption process is kinda binary.... below a certain amount of input heat, the circulation / cooling stops altogether instead of tapering off linearly in spite of continued heat input.  So if the flame is present but reduced in size due to a dirty orifice, you might have no cooling on gas..... as in my case.  

I have also found that the Dometic manuals are amazingly pathetic.  For example, they show you (with PICTURES, even) how to make ice in two paragraphs.... paragraph 1 shows putting water in the ice cube tray (with photo) and paragraph two shows placing the ice cube tray in the freezer (with photo).  Golly, how would I EVER have figured that one out??? By contrast, the troubleshooting section under "refrigerator does not cool adequately" completely omits checking that the unit is level.  

Paul
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