Refrigerator Problem; Dometic RM 2652/2852

[meierjn]

Well, it finally happened... I've got an issue with our fridge. A little bit of history regarding the issue.

The fridge had always worked well. We didn't have any issues whether it was plugged in, or running on propane. We've always kept the back-side of the fridge clean and free of dirt or dust. I've double-checked, and it is clean. We were out at a friend's site for the weekend and the fridge worked fine. There was no power, so the fridge ran on propane all weekend without any issues. We came back home, unloaded, and left the fridge off for a couple of days. On a Wednesday evening i plugged the trailer in and turned on the fridge. On Thursday morning, I confirmed that the fridge was cold. All was well! When we went out to load the trailer on Friday before leaving the fridge was no longer nice and cold! I didn't have time to troubleshoot, so we headed out to the lake with our coolers in tow. Over the weekend I tried to get the fridge working on propane or on power and neither would work. The "check" light never comes on whether the fridge is in "auto" or in "gas" mode. When I feel the flue baffle it is warm and when on gas, the burner does light. I've never messed with the climate-control switch, so it has remained in the off position. It should also be noted that the trailer while at home, and at the lake is very level. I know that there are issues with these units when they are not level! The temperature control sensor is in the same position that it has always been.

I've went through the manual and I am at a loss. Normally I'd expect either the electrical, or the propane cooling function to have failed, but not both. If anyone has any suggestions or ideas, I'd greatly appreciate it.

Thank you!

 

[Henry J Fate]

It sounds like a bad cooling unit.

Carefully monitor the propane flame to make sure it is staying lit and not cycling at an improper inside cabinet temperature.

You can do the same when the RV is plugged in by using an amp probe on the 120volt fridge circuit.

The propane flame is pretty fool proof. If the flame is there, then you know heat is too.

Are you experiencing no cooling or not enough cooling ?

 

[Kirk]

First, here is a copy of the Dometic Service Manual that you can download. I would check to be sure that that you have at least 11V to the control systems. I think that there is a good chance that Henry is right and the cooling unit has failed but I would do a few tests first.

 

[Rene T]

How old is the fridge?

 

[meierjn]

How old is the fridge?

The fridge is in a 2003 5th wheel so it is of that vintage.

 

[meierjn]

It sounds like a bad cooling unit.

Carefully monitor the propane flame to make sure it is staying lit and not cycling at an improper inside cabinet temperature.

You can do the same when the RV is plugged in by using an amp probe on the 120volt fridge circuit.

The propane flame is pretty fool proof. If the flame is there, then you know heat is too.

Are you experiencing no cooling or not enough cooling ?

I will have another look next weekend when we are onsite. I'm pretty sure it is good because it does light on propane, and you can feel the heat on the flue.

 

[meierjn]

First, here is a copy of the Dometic Service Manual that you can download. I would check to be sure that that you have at least 11V to the control systems. I think that there is a good chance that Henry is right and the cooling unit has failed but I would do a few tests first.

Thanks for the Service Manual. I'll print it out and have a look.

 

[tlmgcamp1]

The thermistor is common to both propane and electric operations. If it is not asking for cold, you won't get cold.

 

[John From Detroit]

The "Check" light means a propane ignition failure... That's the only thing it checks.. The rest of the system is up to you.

How old is this unit? 10 years (Give or take) I'd look near the burner for what appears to be either Rust or a yellow powder... Looked rusty to me. it's kind of powder however.

IF you see it.. Likely need a new cooling unit.

 

[Rene T]

The "Check" light means a propane ignition failure... That's the only thing it checks.. The rest of the system is up to you.

How old is this unit? 10 years (Give or take) I'd look near the burner for what appears to be either Rust or a yellow powder... Looked rusty to me. it's kind of powder however.

IF you see it.. Likely need a new cooling unit.

John, see post #5. It is 21 years old.
I must have missed any pictures.

 

[Henry J Fate]

I will have another look next weekend when we are onsite. I'm pretty sure it is good because it does light on propane, and you can feel the heat on the flue.

Definitely make sure constant heat is being applied.

Another indicator is if you or any occupants experienced an odor of ammonia or if you can see any evidence of a leak in the form of a yellowish powder.

Good luck with everything. It is a project to first figure out what you want to replace the fridge with and then the replacement process. Replacing the cooling unit is another possibility if everything else is good and the cooling unit is in bad.

Here is a link to a previous thread of a bad cooling unit.

https://www.rvforum.net/threads/rv-fridge-and-yellow-powder-uh-oh.47844/

 

[CharlesinGA]

The yellow stuff being referred to is chromate used as a corrosion preventive on the inside of the system. It is a carcinogen and easily absorbed thru the skin, so do not touch it, use latex or nitrile gloves and a mask during cleanup, should you encounter it.

Charles

 

[Kirk]

Since the RV is now 21 years old, the refrigerator probably is the same age and that makes the cooling unit even more suspect. If it were my RV, I would give serious consideration to upgrading to one of the new 12V, compressor cooling units or even the entire refrigerator. They cool much better than the absorption models and are proving to be a good choice for RVing.

 

[CharlesinGA]

Since the RV is now 21 years old, the refrigerator probably is the same age and that makes the cooling unit even more suspect. If it were my RV, I would give serious consideration to upgrading to one of the new 12V, compressor cooling units or even the entire refrigerator. They cool much better than the absorption models and are proving to be a good choice for RVing.

Only..... provided that the OP has a decent amount of solar and batteries, or always camps in RV parks with hookups.

For me, no solar, don't really want it cluttering the roof and I do fine with one plain old group 24 battery that is now at least 5 years old or more and still works fine. I am in hookup locations only about 50% of the time. I'm a big fan of keeping it simple and if my Absorption fridge fails, its getting a new cooling unit. RVFixer replaced his cooling unit with good success and I have a copy of his through discussion on how he accomplished this.

Charles

 

[Gary RV_Wizard]

The thermistor is common to both propane and electric operations. If it is not asking for cold, you won't get cold.

Right, but if it is not asking for cooling, the gas flame won't be lit either. Ergo, the thermister is functioning.

 

[tlmgcamp1]

Right, but if it is not asking for cooling, the gas flame won't be lit either. Ergo, the thermister is functioning.

Is the flame the burner or the pilot?

 

[Kirk]

Only..... provided that the OP has a decent amount of solar and batteries, or always camps in RV parks with hookups.

Do you have experience with them? I do not but my son has one in his new trailer and it has a lithium battery and does just fine for a night or two.

 

[Gary RV_Wizard]

Is the flame the burner or the pilot?

The burner. That refrigerator is a DSI model - Direct Spark Ignition - and no pilot involved. When the thermister reports a too-warm temperature, the controller triggers flame ignition in LP Gas mode or turns on the 120v electric in AC mode. The gas flame is an easily visible indicator that both the thermister & the controller are doing their jobs.

 

[rvlifer]

Only..... provided that the OP has a decent amount of solar and batteries, or always camps in RV parks with hookups.

For me, no solar, don't really want it cluttering the roof and I do fine with one plain old group 24 battery that is now at least 5 years old or more and still works fine. I am in hookup locations only about 50% of the time. I'm a big fan of keeping it simple and if my Absorption fridge fails, its getting a new cooling unit. RVFixer replaced his cooling unit with good success and I have a copy of his through discussion on how he accomplished this.

Charles

I dont know anything about the fridge the op referenced but i love the residential fridge in our rv. I dont have to worry about it breaking down, it will probably last longer than the rv, and it uses very little power. If i hsve to replace it i can find one anywhere and not spend tons of money. You do need a good inverter for it but adding a single extra battery is more than enough to power it unless you boondock a lot. Even a lithium battery is cheaper than an rv fridge.

 

[Kirk]

The gas flame is an easily visible indicator that both the thermister & the controller are doing their jobs.

As a troubleshooting aid, you can remove the 2 pin plug from the circuit board that's for the thermistor and disconnecting it will trigger a constant cool mode so that you know for sure what you have happening.

I'll print it out and have a look.

Did you get the manual and figure things out?