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Topic: Dometic RM2652 problem lighting gas

Posted By: Wounded by the Dish on 01/10/05 03:41pm

The last two trips out in the trailer, the fridge would not light initially. I could not hear the igniter working when I turned it on, and I normally can. The trailer is stored in a lot without electrical hookup, but the two-year-old battery was good enough to run the electric tongue jack before hooking up the truck. I’d get silence, a barely audible thunk a few seconds later, then a CHECK light in half a minute or so. Repeats were no help.

I ran the air out of the gas line as usual before trying to light the fridge and still had gas at the stove next to the fridge after the fridge failed to light several times.

The LP bottle we’re on is low, but I had both bottles' valves open, the changeover valve never switched over and the stove's burners still worked.

The first trip, after starting to tow, it occurred to me that the battery might have been too low for the igniter to work until I hooked up the truck, so I pulled over and tried again to light it. It lit right away, but I did not replace the battery because the tongue jack had worked adequately. I was not convinced that was the cause.

The second trip, I did the pull over and try again trick, but with no luck this time. Two hours later at the campground it still would not light. The fridge cooled fine on electrical hookup. Then one day later it again lit fine on gas before heading out.

Is the battery voltage thought a red herring? Where should I start? Thanks, folks.

John


Posted By: Chris Bryant on 01/10/05 04:33pm

On this model, the most common problem I have found is the igniter itself (the metal/ceramic probe) going bad. They get an internal crack, and short out.
You can test this by shutting the gas off (at the back of the refrigerator), and removing the spark wire (if you are brave, hold it about 1/4" away from the terminal- you can get "bit" by the voltage). If the igniter box clicks- or if there is a spark (if you are brave ), then the igniter is the problem.
Often they will work after the refrigerator has been running for a bit- I think the heat drives out any moisture, allowing it to work.

It could be a voltage or LP problem, but the refrigerator takes far lees current and LP than anything else.


-- Chris Bryant
My RV Service Blog
The RV.net Blog


Posted By: Phils on 01/10/05 04:35pm

I have that same refrigerator and have had that same problem.

I found that bouncing down the road caused rust flakes to fall on the burner. One screw will allow you to remove the burner cover and get to it. Once there, you can see if rust flakes are your problem too. I've had this happen about 3 or 4 times now, and immediately check that when I can't get it to light.

Phil


'03 F250 7.3 deezle and '01 Komfort 27FS
Off the grid and outta sight at home
Go camping to have neighbors and amenities


Posted By: AGBAT on 01/10/05 05:50pm

Well this may be no help or more likely not apply, but here goes anyway. After installing a new Dometic in my 5er the tech went around to the propane regulator and adjusted it. I am not sure if your issue is related to the regulator, but he turned mine up/down to get the right color in the flame. Maybe yours needs to be turned up to get enough gas at the right pressure to the igniter. I am relating what I saw the tech do. I am not trying to demonstrate any expertise in this area. Good luck

BTW: on mine he made the adjustment at the screw in the center of the switch over knob.


Posted By: rvsatek on 01/10/05 06:59pm

Quote:

I am not sure if your issue is related to the regulator, but he turned mine up/down to get the right color in the flame.

---------------------------------------------------------

That is scarry. You need a new tech if that is the way he adjusted the gas pressure. Gas pressure is critical for proper operation of LPG appliances and should be measured by someone that has the right equipment and knows how to use them.

ChirsBryant is right about the short on the igniter. Easy to test.


Larry
1994 Ford F250/7.5L/410 gears
2001 Keystone Sprinter 276RLS 14' slide


Posted By: COBIAKING on 01/10/05 08:18pm

My Dometic mod RM2652 Fridge burner lights and burnd for about a minute then I hear a click and the burner goes off. I have checked and there isn't any rust built up on the burner. I can turn it off and it will lite again then burn about a minute and goes off again. There is a little piece of metal w/a wire attached that is in the flame that gets red when when the burner is on. It works on Elect ok.

* This post was edited 01/11/05 09:55am by COBIAKING *


Don & Mary Ann
2 Toy Poodles Mitzi & Francoise 1996 29' GulfStream class C and 2003 Jayco egale pop up


Posted By: Wounded by the Dish on 01/10/05 08:25pm

Thank you very much for the tips folks! I'm headed out of town tomorrow and I'll check out your suggestions in a week or so. Other ideas are still welcome!

John


Posted By: Wounded by the Dish on 01/28/05 11:38pm

Well, I went out to the trailer to start investigating the problem using your suggestions. First I wiggled the wire to the igniter. Then I turned on the fridge. The igniter clicked and the fridge eventually lit. I had neglected to take a Phillips screwdriver with me so I could not take off the covers on either end of the igniter wire so I couldn't tell whether it was corroded or loose. I'll do that next time, but until it starts acting up again, I'm stuck.

Thanks for all your suggestions and PMs.

John


Posted By: NetBoy on 01/29/05 01:13am

Hi, Dometics are infamous for having the "Check" light come on when trying to run on gas. It is often erratic -- the thing will run fine on for some period of time (a minute, 10 minutes, maybe even hours) and then quit with the Check light illuminated.

From your description it does not sound like that is your exactly problem, but here is a Dometic service bulletin that will help you: Troubleshooting Erratic Check Light Problems

That bulletin will walk you through troubleshooting the propane and electronic parts of your Dometic -- the spark ignitor, the thermocouple, the gas supply and flame, and the control board. Most of the troubleshooting can be done with simple hand tools and a digital volt meter.

However, the first thing I would do is take your RV battery home and charge it up fully. Dometics are known to cease to operate if the 12v source is low. I would also get that low propane tank filled just in case.

If that doesn't take care of it, follow the service guide to check your ignitor, your gas solenoid, and your thermocouple, inspect the gas flame, etc. If all of the other stuff checks out, you most likely have a bad control board (a VERY common Dometic problem). The best fix is to get a Dinosaur Electronics replacement board, which is an aftermarket board that fixes the problems which result from the underdesigned Dometic board. The Dinosaur board costs about $100, and is an easy project to change out.

There are lots of past posts on this forum about Dometic refrigerator problems, so doing a search will give you lots of good info.

Keep us posted.


NETBOY™
---
Visit Netboy's Camper Project's Page = Lots of mod projects to my truck and camper.

My newest rig -- 2004 Thor Chateau 21RB:



Posted By: Wounded by the Dish on 03/20/05 03:25pm

Since I posted last I've been out of town at length and gone on one camping trip. The refrigerator lit fine when I gathered my tools and went to the storage lot to test the things you all suggested. I then towed it home to clean it up some, plugging it into electricity while home and the fridge worked fine. Tested the gas operation again and it was good. I began to think it had been corrosion on electrode wire connector (I'd removed and replaced the connector and electrode to inspect them).

We then left on a trip from home. All loaded up and ready to go, I pulled the electric cord to the house and it would not light! I should have taken the time to troubleshoot then, but I did not. We went to the campground where it worked fine on electricity, as always. Before heading home it lit fine on gas.

Today, after reading for about three hours all I could on this forum and using Google to find other sources, I gathered up my tools and voltmeter and went to the lot to see if it would act up. It again lit fine on gas.

Now to help you folks out a little.

From what I read, the refrigerator will operate down to 9.6v DC (number not mentioned previously), so I've eliminated a low battery as the cause of my problem (it would still operate the tongue jack well). Chris Bryant said this was the case and the Dometic Manual confirms that.

There's a great troubleshooting procedure in the Dometic Service Manual here starting on page 9 which I will use next time it acts up.

I also found that the Dinosaur Board circuit board which fits a ton of Dometic Refrigerators, Model P-711 available here for $99, has a feature that will retry a failed lighting sequence every 30 minutes. It also fixes the frequent Dometic problem caused by using a common ground for two circuits and incorporates adjustable temperature control. Worth the money to me whether or not that is the source of my problem.

At any rate, I now know how to attack this problem and you folks got me started.

Thanks very much.

John


Posted By: Duramax1 on 03/20/05 05:17pm

I had the same problem this week and took it in for servicing.

The technician removed two screws and the cover from the ignitor board, which is a small box that has three wires going into it, (just follow the wire back from the ignitor electrode), blew on the three electrical connectors, reinstalled them and the fridge has been working ever since.

Takes all of two minutes to do.

I was told by the tech that he regularly sees this check light malfuntion. I asked about changing the board and he said that if it worked when returned to Dometic, and it probably would, that it would not be covered by warranty.

He said that condensation is his best guess as to what causes the problem


2008 Chevrolet Silverado 2500HD DA LTZ
2009 Sundance 2900MK


Posted By: Texas Vet on 03/20/05 05:39pm

John,
A lot of the problems I see like these (the RM2652 is no exception) are caused by connections to the board or bad grounding(s). Remove the connectors to the circuit board and clean the contacts with a pencil eraser. Plug and replug the connectors a few times and see if this makes a difference. This will clear up a lot of intermittent problems.

On the road...


Lew



Posted By: Wounded by the Dish on 04/21/05 05:37pm

One more thought on this topic. Although the refrigerator circuit board is supposed to operate on voltage as low as 9.6, that does not necessarily mean the igniter will have the voltage it needs to make the spark jump, does it? Maybe low battery after all.

I have used the trailer for another 12 days now, lighting it on gas seven times and it worked perfectly every time, rainy, dry, sunny, humid. Every time. Never sat long between trips, though and maybe that is responsible for it's performance.

I had a voltmeter and tools with me at all times on those trips so maybe it was just scared it into acting right!

John


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