 |
06-28-2023, 04:23 PM
|
#1
|
Junior Member
Join Date: Nov 2022
Location: Everywhere - I"m full timing
Posts: 2
|
Fridge cools on 120AC, but not propane or 12V
Hi All,
I have a a strange issue with my fridge (Dometic RMD8555), it cools completely fine when plugged in on AC power and but will not cool the fridge on propane (which is strange because the freezer works fine on propane).
Same is the case on 12V (freezer works, but not the fridge).
RV tech says he can't find anything wrong with the unit, apart from the fact that the fan behind the fridge won't come on when running on propane.
Anyone have suggestions for how to troubleshoot this?
|
|
|
 |
Join the #1 RV Forum Today - It's Totally Free!
iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!
You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!
|
06-28-2023, 04:34 PM
|
#2
|
Senior Member
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 4,724
|
1. You need to fill out your profile with what coach the fridge is in - either that or tell the group what the fridge is in as it makes a difference.
2. If the fridge is in a slide, it very well might not be installed right (and possibly not installed right even if not in a slide).
Ventilation is crucial to LP fridges.
3. LP fridges cool from the freezer down, and their temperatures don’t fall at an even or “tracking” rate. The freezer has to get close to freezing before you begin to notice any appreciable cooling on the fridge section.
4. Not sure on your unit, but if there is a sliding thermistor mounted to the right hand 1-3 fins of the fridge evaporator, make sure the plastic holder is flush with the bottom of the fin it’s on.
Nothing in the refrigerant system modulates the refrigerant flow - the thermistor just tells the control to run until it see’s the preprogrammed temperature setting.
__________________
91 Ultrastar Champion02 Georgie Boy Landau 8.1l Workhorse
03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
|
|
|
06-30-2023, 11:22 PM
|
#3
|
Senior Member
Join Date: Mar 2019
Location: Braidwood Il.
Posts: 8,300
|
The burner can get plugged. Remove orifice soak in alchahol only blow it out with your mouth. Don't use compressed air or spray cans don't poke anything through there it's jeweled has like a little glass bead that can be damaged. You can blow out burner mix tube with tiny bottle brush or several pipe cleaners. One owner had wrong burner tube installed by PO. Make sure spiral diverter is in burner chimney some are built in others dangle on a heavy wire from the top.
__________________
95 Monaco Crown Royale
M11 400hp, 4060 trans.
Aquahot, Generac Guardian7.5k
|
|
|
07-01-2023, 08:16 AM
|
#4
|
Junior Member
Join Date: Nov 2022
Location: Everywhere - I"m full timing
Posts: 2
|
Quote:
Originally Posted by 153stars
The burner can get plugged. Remove orifice soak in alchahol only blow it out with your mouth. Don't use compressed air or spray cans don't poke anything through there it's jeweled has like a little glass bead that can be damaged. You can blow out burner mix tube with tiny bottle brush or several pipe cleaners. One owner had wrong burner tube installed by PO. Make sure spiral diverter is in burner chimney some are built in others dangle on a heavy wire from the top.
|
Thanks, I'll try this. Does this also explain why it's not working on 12V?
|
|
|
07-01-2023, 08:33 AM
|
#5
|
Senior Member
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 4,724
|
Fridge has to have 12 volts to operate, regardless of fuel source.
Does your fridge have a 12vdc heater? Makes no sense to have one unless you don’t have LP on the coach (12vdc heater takes a lot of battery to drive a fridge).
__________________
91 Ultrastar Champion02 Georgie Boy Landau 8.1l Workhorse
03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
|
|
|
07-01-2023, 09:23 AM
|
#6
|
Senior Member
Texas Boomers Club Forest River Owners Club Ford Super Duty Owner RV Trip Wizard
Join Date: Jun 2020
Location: Heart of Texas
Posts: 7,549
|
3. LP fridges cool from the freezer down, and their temperatures don’t fall at an even or “tracking” rate. The freezer has to get close to freezing before you begin to notice any appreciable cooling on the fridge section.
^ this makes the most sense to me.
Even on 12v you're cooling in the freezer per your subsequent post. So, the salient point here is the freezer is cooling but it's not working its way to the fridge. The question, and most possibly the answer, is how your unit draws the cold to the fridge section.
|
|
|
07-01-2023, 09:22 PM
|
#7
|
Senior Member
Join Date: Aug 2001
Location: North America somewhere
Posts: 32,253
|
Quote:
Originally Posted by SmilingNomad
Hi All,
I have a a strange issue with my fridge (Dometic RMD8555), it cools completely fine when plugged in on AC power and but will not cool the fridge on propane (which is strange because the freezer works fine on propane).
Same is the case on 12V (freezer works, but not the fridge).
RV tech says he can't find anything wrong with the unit, apart from the fact that the fan behind the fridge won't come on when running on propane.
Anyone have suggestions for how to troubleshoot this?
|
"fan not running on propane" is likely the problem. An absorption cooling unit is designed to cool the freezer first, then as the refrigerant falls(gravity flow) it cools the refrigerator section-IF the refrigerant is losing heat fast enough.
Place a small blower-type fan near the bottom blowing up on the refrigerant piping and observe results.
https://www.newegg.com/p/1YF-00B0-00...9694-_-Product
I have one on my refrigerator and it cools great, in fact I had to reduce the fridge setting to prevent milk from freezing .
I bought my fan when I bought a Fridge Defend protective unit; which protects the cooling unit from damage when the fridge is not level.
__________________
2000 Winnebago Ultimate Freedom USQ40JD , ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;GS Life member,FMCA " My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy
|
|
|
07-01-2023, 10:33 PM
|
#8
|
Senior Member
Join Date: Nov 2015
Posts: 28,354
|
Dometic RMD8555........
This is a fancy absorption fridge so cooling unit functions the same as any absorption fridge
*fancy in that it uses a software controller & dual gas valve assembly
When 'sufficient' heat is generated enough ammonia is boiled into a hot vapor which is then cooled enough to condense into a liquid
When his liquid contacts the hydrogen gas it absorbs heat from freezer section First and then absorbs heat from food compartment
If the liquid ammonia via condenser is inadequate there will not be enough absorption capability left after going through freezer to properly cool food compartment
**Freezer temp at 10*F then food compartment can cool
IF inadequate..........heat source lacking, transfer of heat lacking or ventilation obstructed
Cooling unit functions properly on 120AC heat source so that is not the issue
Freezer cold/food compartment not on Gas or 12VDC
Low LP System Pressure
Dirty Burner
Dirty flue/flue baffle
Low 12VDC Voltage
12VDC heater resistance low
Exterior Fan is probably NOT coming on when on propane due to lack of sufficient heat being generated so temp at condenser is not closing the t-stat for fan (same for 12VDC heater)
**does it run when on 120VAC heat source???
__________________
I took my Medication today. HAVE YOU?
Dodge 3500 w/Tractor Motor
US NAVY---USS Decatur DDG-31
|
|
|
07-02-2023, 06:34 AM
|
#9
|
Senior Member
Commercial Member
Join Date: Jun 2015
Location: Montana
Posts: 828
|
Dometic not cooling on LP
Quote:
Originally Posted by SmilingNomad
Hi All,
I have a a strange issue with my fridge (Dometic RMD8555), it cools completely fine when plugged in on AC power and but will not cool the fridge on propane (which is strange because the freezer works fine on propane).
Same is the case on 12V (freezer works, but not the fridge).
RV tech says he can't find anything wrong with the unit, apart from the fact that the fan behind the fridge won't come on when running on propane.
Anyone have suggestions for how to troubleshoot this?
|
Let's return the smile to the Nomad,
the reason the fans are not running is that the fridge is not getting enough heat to run the process, in turn not enough refrigerant is being produced. This overheats the boiler while the rest of the cooling unit runs at lower than normal temperatures. The refrigerant is the only thing that keeps the boiler running at its normal temperature without preventive measures.
See these videos, these are for a Norcold fridge, but the principles are the same:
5 LP System Pressure & Filter:
6 LP Gas Burner Igniter Jet & Flue:
Let us know if we can be of further help, Paul and Mao
|
|
|
07-03-2023, 12:20 PM
|
#10
|
Senior Member
Gulf Streamers Club Ford Super Duty Owner
Join Date: Aug 2015
Location: Memphis, TN
Posts: 4,812
|
One owner changed LP REG for other reasons, had 9 vs 11 inches water, said Refrig suddenly worked better than ever.
__________________
(TerryH.) 2000-GS Conquest Limited 6266 Class-C 99-E450SD V10
|
|
|
07-09-2023, 07:04 AM
|
#11
|
Senior Member
Join Date: Apr 2022
Location: Renton-Highlands,Wa./HB,Ca./Fujieda-Japan
Posts: 955
|
It also helps quite a bit to have a small battery operated fan inside near the bottom moving air around. I also have one mounted on the backside of the fridge that assist in keeping air moving upward out the roof vent.
Fans I have... https://www.amazon.com/Fridge-Fan-Co...zcF9hdGY&psc=1
__________________
1994 Southwind Storm 28ft - 454TBI w/4L80E
VIN#1GBJP37N4R3314754
Flight System G-Man 360 generator man (PM me)
|
|
|
07-18-2023, 10:23 PM
|
#12
|
Senior Member
Join Date: Jul 2019
Posts: 603
|
This video may help.
I would check the relay mentioned. Mine was bad, so fans would never start. Easy to check/replace without removing refrigerator.
Since I fixed the rear fans and installed a fan on the inside of the fridge pointing at the fins, mine stays at 34 to 36 degrees.
__________________
2012 Bounder 35k
|
|
|
 |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|