Dead Dometic RM8501 - R-pod Owners Forum

Author

Share Topic

Topic Search

Topic Options

spydie

Senior Member

Joined: 25 Jul 2017
Location: New Mexico
Online Status: Offline
Posts: 159

Topic: Dead Dometic RM8501
Posted: 07 Aug 2017 at 12:54pm

From the Dometic manual:

Determine if the refrigerator works on one heat source but not another by testing it in the alternate modes. Also, ask the customer if he gets better cooling results from one energy source than another. If this is true, it indicates the problem is NOT in the cooling unit.

Also it says not to use compressed air to blow out the orifice. Clean in alcohol and let it air dry.

If anyone would like a copy of the service manual, I'm hosting a copy in my dropbox at this address:

https://www.dropbox.com/s/32i0fssts7yrw61/dometic-service-manual%20copy.pdf?dl=0

2018 R-pod 176
2017 RAM 1500 5.7L Hemi

Wood River Pod View Drop Down

Senior Member

Joined: 30 Sep 2016
Location: Wood River, ID
Online Status: Offline
Posts: 153

Posted: 07 Aug 2017 at 1:15pm

Fred, thanks for the link back to the previous post. I kind of remember seeing that right after we bought our 179.

Paul, thanks for the step by step instructions.

Most helpful!

I so appreciate the level of knowledge and the willingness of this community.

Thanks

Smith's in Hailey
Early 2017 179 HRE

Wood River Mods

pgoelz

Groupie

Joined: 22 Jul 2016
Online Status: Offline
Posts: 70

Posted: 07 Aug 2017 at 1:36pm

And thanks for the link to the service manual. Note that is NOT the RM8501 manual (which can be found on the net) but there is a LOT more detailed operational and testing information in the one you linked to vs. the actual RM8501 manual.

I put a remote reading thermocouple (former engineer here) in the fridge so I can keep tabs on the internal temps without opening the door. Looks like on the middle setting, it is holding right at 41 degrees. I'll call Dometic and see if I can get them to tell me if that is nominal or not. I suspect it is.

Paul

spydie

Senior Member

Joined: 25 Jul 2017
Location: New Mexico
Online Status: Offline
Posts: 159

Posted: 07 Aug 2017 at 1:45pm

Originally posted by pgoelz

And thanks for the link to the service manual. Note that is NOT the RM8501 manual (which can be found on the net) but there is a LOT more detailed operational and testing information in the one you linked to vs. the actual RM8501 manual.

Paul

Paul, There are a lot of variables and I doubt there is any "Normal." If it's 70 degrees outside the temperature in the fridge will be a lot different at any setting than if it's 100 degrees outside. And we found out today that it makes a BIG difference if the unit is IN the Pod or sitting on a test bench. Because of the refer being in a slide-out, they unable to put a roof vent (which would be a lot more efficient) and these Dometics apparently lose a lot of efficiency just because of being mounted in the RV. Dometic will tell you the only way they accept temperature readings is if you are doing the "water test." That is, a glass of water in the fridge with a bulb thermometer in it. It's the only way they'll accept readings from a service department (as my service department told me today after they've been talking to Dometic service directly).

I didn't realize the service and diagnostic manual I posted was not for the 8501, but you're right, it does have a lot of information in it.

2018 R-pod 176
2017 RAM 1500 5.7L Hemi

marwayne

Senior Member

Joined: 25 Oct 2011
Location: Edmonton AB Can
Online Status: Offline
Posts: 1002

Posted: 07 Aug 2017 at 2:00pm

Here is what I do. If I stand about 2 or 3 feet away from the fridge outside and I can't hear the flame clearly the burner and orifice needs cleaning. I clean mine once or twice a season.

If you want something done right, do it yourself.
2011 RP172, 2016 Tundra 5.7 Litre, Ltd.

spydie

Senior Member

Joined: 25 Jul 2017
Location: New Mexico
Online Status: Offline
Posts: 159

Posted: 07 Aug 2017 at 2:02pm

Originally posted by marwayne

Here is what I do. If I stand about 2 or 3 feet away from the fridge outside and I can't hear the flame clearly the burner and orifice needs cleaning. I clean mine once or twice a season.

I'm going to check that very same thing on mine when I get it back from the service department (of course a lot of that test depends on your hearing! LOL)

2018 R-pod 176
2017 RAM 1500 5.7L Hemi

pgoelz

Groupie

Joined: 22 Jul 2016
Online Status: Offline
Posts: 70

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

spydie

Senior Member

Joined: 25 Jul 2017
Location: New Mexico
Online Status: Offline
Posts: 159

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?

2018 R-pod 176
2017 RAM 1500 5.7L Hemi

pgoelz

Groupie

Joined: 22 Jul 2016
Online Status: Offline
Posts: 70

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

spydie

Senior Member

Joined: 25 Jul 2017
Location: New Mexico
Online Status: Offline
Posts: 159

Posted: 07 Aug 2017 at 3:37pm

Tell me what a delta measurement is please

2018 R-pod 176
2017 RAM 1500 5.7L Hemi