Rm2620 Dometic Reefer problem

[Raynbowman]

Refrigerator will not cool properly 45f, freezer will cool to minus 20f. I have cleaned orifice, cleaned solenoid valve and all connections. Cleaned flue and replaced insert. Replaced thermistor. Both ac and propane work this way.

So to try and fault the black box, I shut down refrigerator and disconnected all power sources. I removed incoming leads to propane solenoid valve, and powered solenoid up with 12 volt dc power source. I ran overnight and fridge went to 80f and freezer 50f. I reconnected everything stock and fired up on propane and had ice in freezer in 3 hours.


My question is then: is there or are there any electrically controlled devices (valves) within the walls of the unit that have to be controlled with 12 volts, and without any power source to black box and eyebrow, which is why when I isolated solenoid valve I got no cooling what so ever.

A lot of searches have suggested the thermistor was at fault, not so in this case.

Is it the black box, or a faulty (unknown) valve within the walls of the refrigerator.

I would love so much to have any input into my dilemma.

Much appreciated

[wasatchmtnatvr]

Fault is not with controls. On full bypass meaning thermistor unplugged from board, it will get below freezing. It should be capable of cooling 60 - 80 degrees below ambient air temperature. You need to fix airflow (venting requirements). Fiberglass bat insulation sides and top to have insulation close gap on sides and top helping to insulate box from exterior heat. Biggest issue is 5" gap at rear. You need to build an additional wall (box baffle) that closes that gap to 1" or less. Goal is rising airflow up at rear of refer is forced to pass across refer coils and fins to dissipate heat off them and escape out upper refer vent lid. Also use oem lid on roof. DO NOT USE AFTERMARKET CAMCO BRAND LID ON OEM DOMETIC BASE. They are very restrictive on dometics base and cause airflow problems. If CAMCO brand lid is used you must modify oem base vent to vent properly.

[Raynbowman]

Walls are insulated back side is approximately 5" clearance, top is unobstructed and vented.

Reefer is out of camper for now. When using LPG and using eyebrow control at top of unit, there is no change in flame when adjusting from 5 to 1 or 2 or 3 or 4 Flame does not go out, flame does not change. Fridge compartment temperature is at 38f

wasatchmtnatvr, what I do not understand is, if all controls are out of picture (disconnected) and LPG is applied to system by bypassing controls (it went to 50f and 80F overnite), why then does the unit not just turn into a freezer completely? Does the unit not become like my 30 old, non technical reefer? Pull to over ride thermocoupler unit and activate striker to start burn until it has developed enough heat to develop enough currant to keep solenoid open.

Is the board in Dometic faulty?

Your analogy is spot on.

[wasatchmtnatvr]

If heat source is always on and not cool enough look at installation issues or venting. Have 0" sidewall and top clearance by using insulation to snug to refer sides and top. Maximum .5" refer clearance to back wall. box baffle if necessary. Refer in slide? diverter baffle upper vent to direct rising air thru upper fins.

[wasatchmtnatvr]

Divide problem in half. Is it control issue or installation, venting, cooling unit issue? . Control issue test. At stated 38f turn refer to lp. so you can here flame activation or deactivation. Is flame off at 1 setting? If yes scroll slowly toward 5 setting briefly pausing between each command. A what number does flame come on? On a functioning thermistor and board the setting of 1 is 43f., 3 setting is 38f., and 5 setting is 34f.. if matches your readings and you want colder you need to engineer settings to go colder. Couple options, both items trick existing thermistor to keep refer on to achieve colder setting. dometic thermistor adjuster #2932164011 tricks to 5 degrees colder. Or Dinasaur "thermistor simulator for dometic" part is varable from 3 - 7 colder .

[dougrainer]

DrewE wrote:

dougrainer wrote:
There is NO WAY he got minus 20. He had to be stating 20 degrees. You have your last statement backwards. There is NO way to control the freezer, the tstat system controls the lower refer section. Doug

It would seem to me, if there was say a significant air leak in the fridge portion, the thermistor would constantly call for cooling, and the freezer get very cold while the fridge compartment would remain too warm. Am I missing something?

The freezer would NEVER get to more than -5 and NOT -20 no matter if you left the bottom door open and the refer never shut off. Doug

[Raynbowman]

My deepest apologies, I am up in Canada and am reading 2 different thermometers in 2 different compartments. I should have written all temps in Fahrenheit. So it is now 38 deg Fahrenheit in fridge and 0.4 Fahrenheit in freezer. It has cooled off a bit up here today and so this is reflecting currant temperatures. I am going to clean all contacts and apply dialectic grease to all contacts. New thermistor is as high as I can get it in fridge compartment and brow is set at 5. I would like to get fridge to operate 34 Fahrenheit. Did dollar bill check on perimeter seal and it is good.

Sorry for confusion.

[DrewE]

dougrainer wrote:
There is NO WAY he got minus 20. He had to be stating 20 degrees. You have your last statement backwards. There is NO way to control the freezer, the tstat system controls the lower refer section. Doug

It would seem to me, if there was say a significant air leak in the fridge portion, the thermistor would constantly call for cooling, and the freezer get very cold while the fridge compartment would remain too warm. Am I missing something?

[dougrainer]

There is nothing in the walls or anything else. BEFORE you replaced parts, you should have wired the 120 element direct to 120 for 24 hours. If the freezer did not get blow 10 degrees and the refer below 40 degrees, you have a BAD cooling unit. From what you stated, you have a blocked Cooling Unit. Doug

[dougrainer]

There is NO WAY he got minus 20. He had to be stating 20 degrees. You have your last statement backwards. There is NO way to control the freezer, the tstat system controls the lower refer section. Doug

[cooldavidt]

I have a similar problem.

I watched some YouTube videos and it helped a lot.

This one guy touches all the bases

https://www.youtube.com/watch?v=LpnG50EpQb0

Presumably you have no codes..I'm close to you in Kits in Vancouver so if you want to talk reply here and we can set up a call.

[tvman44]

When you started out -20°F in freezer, the refrigerator should have been colder than 45°F. As far as I know there is no way to control the fridge separately from the freezer.