New Dometic RM2510 Question

[dbj216]

I have installed a new Dometic RM2510 in my 66 Trade Wind. I have utilized the original floor venting and installed a Valterra 12v fan that comes on at 85 degrees to push air out the chimney. I may not have enough fresh air inlet area using the floor vent, but figured the fan would compensate. Air flow over the heat exchanger coils is important for proper cooling. I don't think it is a factor in the gas operation of the fridge. The fridge sets in the cabinet tight, with only about 3" from the fridge to the interior wall. There is no side wall vent unless I take the old fridge access door off.

I tested the fridge for 24 hours on 115v power with very good results. Cabinet was down to 27 degrees at max cold.

Today I tested the fridge on gas power. After about an hour I heard a loud bang in the direction of the trailer. There was no smoke or damage. The interior cabinet above the fridge where the plastic "chimney" runs does smell hot. I kinda figured it was the new fridge outgassing manufacturing oils and the like. My new furnace smells hot too. The flue pipe does seem warmer on gas than electric.

Has anyone ever experienced a flue or chimney bang while running a Dometic fridge on gas? Is it possible for the fridge to allow gas into the burner but fail to ignite it?

David

[geodazed]

David,
Never have heard of gas ignition like that. Has it recurred? I am finishing a frame off restoration of a 66 tradewind and am just in the process of putting the dometIc refrigerator back in. New fiberglass chimny, new flooring and considerating just replacing access dor with vented door rather than cutting a big hole in new floor and belly skin. Hopefully this provides enough air flow for frige. How big was your original floor vent opening? Mine was a 12 by 6 screen covered floor vent with another 12 by 6 screen covered vent in the belly skin underneath.
Plugged in refrigerator and quite a bit of heat comes off the rear coiLs and while fiberglass chimny is warm it seems ok.
John Pittman


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[idroba]

Originally Posted by dbj216

Today I tested the fridge on gas power. After about an hour I heard a loud bang in the direction of the trailer. There was no smoke or damage. The interior cabinet above the fridge where the plastic "chimney" runs does smell hot. I kinda figured it was the new fridge outgassing manufacturing oils and the like. My new furnace smells hot too. The flue pipe does seem warmer on gas than electric.

Has anyone ever experienced a flue or chimney bang while running a Dometic fridge on gas? Is it possible for the fridge to allow gas into the burner but fail to ignite it?

David

The 2510 uses a constant flame ignition system, with the flame going from high to low to modulate the temperature. The gas flame never shuts off and is not re ignited except when there is a total flame failure, then the electronic ignitor re starts the gas. The thing is there is very little reason for the flame to fail once it is lit initially, unless it is blown out and your unit was not moving I assume, just sitting there. If it goes out and does not re ignite in a short time the flame sensor simply shuts the gas off and it cannot re ignite without pressing the interior button to re start the entire sequence.

I cannot see how that system, which does not turn the flame on and off, could cause the problem, unless somehow you had a loose gas fitting, leaking some gas somewhere. A leak could of course be ignited causing a "bang". The only other possibility that comes to mind is a flame failure due to gas tank switchover, then gas being re available within a few seconds and the ignitor causing the excess to ignite causing a bang or pop. This would be quite a stretch though.

I would watch it very carefully to be sure there is no re occurrence. It will run hotter (the plastic chimney) on gas than electric, but probably not enough to make any difference in real operation.

If you have the original hole in the floor and vent on the roof system, you probably do not even need the fan(s) you added.

I put a 2510 in my 74 Argosy, works very well.

[dbj216]

Thank you folks for your responses. I have determined the bang was the neighbor kids getting rid of some 4 of July fireworks. We heard another boom the next day, but the fridge wasn't running. Funny how I get nervous when I first start something up and fret about every little thing. Such good timing by the boys. I light my new fridge for the first time and 30 minutes later they light off a firecracker or something.

I maintained the floor vent 12 by 6. The new fridge actually sits over the vent area somewhat. I installed a 10 by 6 louvered cover in the belly pan. So the fridge draws air from the belly pan area and from the exterior. I do not think I have the vent area that Dometic specifies in their installation instructions, but it is close. I can always use a louvered access door if I find I'm getting the coils too hot, or the fridge is not cooling properly. The fridge is only about 4" from the interior wall. Plenty tight to get a good chimney upward draft due to the heat of the boiler.

The little 12v fan is thermostatically controlled to come on at 85 degrees F. I have heard it run a few times on a hot summer day. It moves air over the coils. But so far the new $1300 fridge is working well. It cools down in about 5 hours and I can modulate the cabinet temp to 35 degrees pretty easily. I don't like getting on my hands and knees to light the gas operation. Seems like there would be a better place for the fridge controls other than the floor.

Boy was I nervous when I heard the bang. But it was not related to the fridge. Kids anyhow!

David

[idroba]

I had thought of the "bang" as something like a toilet lid falling closed, but didn't want to mention it, feeling silly. The fireworks explanation is much better. Glad you solved that problem