RM1350 Fridge - Propane Operations Frustrations

Griswalds · 08-24-2015, 08:17 PM

Our 2016 Lacrosse 327RES has the RM1350 fridge. Since new (March) it's been a bear to light on propane. The dealer checked it and said it was fine. I don't think it is. After taking more than 10 mins (spits and sputters as it tries) to light (even after lighting the stove burners for a few mins), I let it run for about 30 mins. Go back a few hours later, and it will not light. Click click click....poof.....click click click, repeat. I understand air in the line. However, it should not get air back in the line after 30 mins. Forget about it if I let it sit for a day. I don't know if I have a small leak or a problem with the electronic valve. The dealer checked the burner tube alignment and said it was good. Once it lights, it will stay lit until I turn it off. Once off, it's a crap shoot. I never had this problem on other trailers. Any advice, thoughts, similar experiences?

Thanks.

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**Platokidd** · 08-24-2015, 08:56 PM

Hmm... Im not at the cg to look, but I do think I have a gas shut-off under the fridge slide out on the frame. Something simple to check to see if its open all the way.

Griswalds · 08-24-2015, 09:03 PM

Thanks. It does have a shutoff and it's in the open position. That valve feeds the fridge and stove. The stove and oven work fine.

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**Platokidd** · 08-24-2015, 09:23 PM

Have you read page 15,16 and 17 of the manual?
Forest River Forums - Downloads - Dometic RM 1350 fridge users manual

TimVWulp · 08-25-2015, 01:28 PM

Quote:

Originally Posted by Griswalds

Our 2016 Lacrosse 327RES has the RM1350 fridge. Since new (March) it's been a bear to light on propane. The dealer checked it and said it was fine. I don't think it is. After taking more than 10 mins (spits and sputters as it tries) to light (even after lighting the stove burners for a few mins), I let it run for about 30 mins. Go back a few hours later, and it will not light. Click click click....poof.....click click click, repeat. I understand air in the line. However, it should not get air back in the line after 30 mins. Forget about it if I let it sit for a day. I don't know if I have a small leak or a problem with the electronic valve. The dealer checked the burner tube alignment and said it was good. Once it lights, it will stay lit until I turn it off. Once off, it's a crap shoot. I never had this problem on other trailers. Any advice, thoughts, similar experiences?

Thanks.

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Hi I don't think you have a problem with air in the gas line. I believe that the problem is a proof of ignition or flame. The electronic ignition system looks for a small mil volts that is passed through the flame to prove that the LP gas has ignited. You may have a bad electronic ignition control board or the flame is not in full contact with the ignition/flame rod causing a week signal through the flame. Spiders love to build nest around LP burners for some reason and can cause the electronics to short out through the webs.

Grampa Jim · 08-25-2015, 02:04 PM

Tim's got some good advice for you. And being as I was in the heating and AC business for 40 years, let me add this. If the spitting and sputtering is happening,,,,,your gas air mixture may be too much air. The flame should be a nice quiet "roar" when it's operating right. Also your flame sensor could have a very small film of oxidation on it and that'll throw things cattywampus. Putt it out and clean it off with steel wool. Also,,,are you at a higher elevation? That'll throw your gas/air mixture out of wack.

Crockett · 08-25-2015, 03:52 PM

have you burned through one set of gas in the tanks yet?? if the tanks were not purged before filling, you could have air wreaking havoc with that small flame in the fridge.

Griswalds · 08-25-2015, 05:09 PM

Thanks guys. I did burn through a tank of propane. I did some troubleshooting. I removed the burner tube cover and checked the alignment of the igniter. It's writhing spec. The burner and flu were clean. I turned on the fridge and could here gas flowing through the tube. Click click click nothing. I then used a manual lighter and it went poof, but did not stay lit. I then covered the supply line Orpheus with my finger and when I removed my finger it lit and stayed lit. Note: this is where the supply line has a gap as it enters the burner before the igniter. I turned the fridge off and then back on. Click click click nothing. I placed my finger over the outlet again and when I removed it lit and remained operational until I shut it off. It started to make me think that maybe the pressure is to high causing the flame out. When I cover the Orpheus for a second it slows down the gas and allows it to ignite. The flame is blue when lit. This is the only thing o can think of. It's definitely not air or it would not have lit and stayed lit. Thoughts, opinions, you be crazy, etc?

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Crockett · 08-25-2015, 06:17 PM

does the ign probe have a 1/8" clearance from the burner head?? sounds like the gap is off...

Griswalds · 08-25-2015, 06:25 PM

It does. That's the first thing I checked. Wouldn't manually lighting it confirm that it's not an alignment issue? Meaning if it flames out when manually lighting it's something else? That being said, I did check the clearance and it appears to be in spec. Thanks again.

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Crockett · 08-25-2015, 07:08 PM

that vent next to the orifice admits air to get the proper mixture. blocking that to gain operation would indicate too much air to the mixture. could be residual air from improper purge. try another lp tank and purge manifold and see if it improves...

Griswalds · 08-26-2015, 11:54 AM

That makes a lot of sense actually. I'll give that a shot. I decided to play with the igniter position and it lit. Not sure if I got lucky and it would have lit regardless. I turned it off and will try again tonight to see if it fires right up. If not, I'll proceed with switching tanks and purging the manifold.

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Crockett · 08-26-2015, 12:36 PM

you may be in the process of removing the last remaining air. like you said, if it wont light with a flame, then the ignitor is ruled out. the air, if thats the case, will be concentrated with the vapor at the top of the liquid and the first to go. everything being new, i would go with this test before adjusting ect...

Crockett · 08-26-2015, 11:57 PM

Background: tank manufacturers pressure test new tanks with compressed air. They come to the rv manufacturer with that same compressed air. If there is ANY pdi done by mfg they DO NOT use the tanks that the Rv ships with because the RV comes to the dealer with the same compressed air in the tanks. The only exception may be the motorized units. The dealer then must "purge" the tank...

Purging: bleed off all air. Hook up to an lp tank and add lp VAPOR to tank for a few seconds. Bleed off. Repeat a couple more times. Vapor is used so cold liquid lp changing state to vapor during depressurization does not cause moisture in air to condensate in tank. Then fill lp tank.

As you can imagine, this process could be botched or bypassed pretty easily...if lp is added to compressed air in tank, thats a lot of air to screw up A/F ratio, especially in small flames. With a new unit, it seemed like a probable source of the problem.

Griswalds · 09-08-2015, 08:15 PM

Quick update and to say thanks to everyone. After adjusting the igniter it fires up after the first click every-time now. Thanks for all the advice. Working like a charm now.

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rracer5 · 09-08-2015, 08:21 PM

Quote:

Originally Posted by Griswalds

Quick update and to say thanks to everyone. After adjusting the igniter it fires up after the first click every-time now. Thanks for all the advice. Working like a charm now.

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TimVWulp · 09-08-2015, 08:41 PM

Quote:

Originally Posted by Griswalds

Quick update and to say thanks to everyone. After adjusting the igniter it fires up after the first click every-time now. Thanks for all the advice. Working like a charm now.

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Thank you for letting us know what finely fixed the problem.

Glad I could help Tim

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