Dometic RM2310 - 110 Cold, LP Warm

[audiophilepj]

Hey guys, I've been searching around the web for days looking for info regarding my camper frig problems. Here we go...

My RM2310 is not a 3-way, it's only a 2-way,110 and LP only. I've been using it for 5 years without any problems. Last weekend I started my trip from home with a cold frig running from 110. I switched to LP and saw my blue flame burning. I set the stat to max. The blue flame was always lit and burning, but the fridge will not stay cold! It was a hot 90 degree day, and the frig was 70 degrees inside.

No ammonia smell, no yellowish dust. The unit is very clean. It's in a 1992 Pasttime Camper, but stored inside, hardly used from 1992-2008.

The door seals are in good condition.

Ventilation has never changed, and has lots of space.

My propane tank is full. I've tried a different tank, same results. One thing I would like to test is the regulator. I've never been able to see a difference in flame. Even when the thermostat is on "Max", the blue flame is the same. I read somewhere that the flame doesn't get bigger, only burns longer.

The burner jet, burner and flue are very clean. I'll pull off the burner jet and inspect inside of it tonight.

Can I rule out the thermostat since it works on 110? If not, how do I test the thermostat?

Could it be the switch? I've never been happy with the feel of the switch. It is slow and muddy feeling. It's not a clean click, but a slide and stop... Hard to explain. The switch has play in it. It does shut off the gas when I move to electric, and it works when on electric, so I guess it's working. Is that all it does? Nothing with the electric power and thermostat?

When I feel the temp of the electric burner vs the gas burner, they feel about the same temp, hot enough to touch the metal cover, but can't keep my hand on for long (too hot).

Is it true that when running on propane, no electricity is required? No 12v? I don't see any 12v cables running to the frig.

Does the cut-off valve cut off 100% of the propane?

I appreciate anyone's help. Another few days of troubleshooting... and I might give in and take it to a shop.

Thanks, Phil

[dickandlois]

Hi Phil, Welcome to FMCA !

How long has it been sense you used the fridge on LP?

The one thing that I would check is gas heater vent. Mud Dobbers, Wasp and other insects love to build nest in the area.

Think this link will get you to an owners manual for it.

http://bryantrv.com/docs2/docs/operating/rm2310.pdf

Rich.

[wolfe10]

Phil,

Welcome to the FMCA Forum.

You are correct, you do not need 12 VDC for your 2 way model.

Two things come to mind-- the first is that you mention: "Ventilation has never changed, and has lots of space." That is NOT the optimum installation. From the document above, 1" is the proper rear clearance, with zero on sides and top. More than 1" in back allows turbulence rather than smooth air flow up over the cooling unit.

Have you cleaned the propane jet as well as burner tube? Even a spec of dust can restrict gas flow and therefore total BTU's available for "cooling".

And, it is very difficult to tell the proper "flame height" by looking at it. Better to check propane pressure with a manometer or just replace the regulator (around $20).

[desertdeals69]

Check the baffle in the chimney for soot and the location of the flame.

[audiophilepj]

Thanks for the quick responses. I have (attempted to) attach some pictures of what I am battling.

I think the problem is the regulator. I went to purchase a new regulator/hose from my local RV shop. The gentlemen asked if my regulator was adjustable, I didn't think it was, but I was wrong. I popped off a white cap and revealed a red threaded plastic adjustable screw. The plastic piece was barely started in the threads. I screwed the piece in to test the amount of adjustable space. The screw adjusted in almost 1 1/2 inches! The red piece moves VERY easily, so easy that I believe it could have vibrated lose.

I unscrewed the red piece back to where it was when I found it. I turned on the gas and began adjusting in the threads while watching the size of the flame. What a difference!

I couldn't even hear the propane burning where it was previously at. As I screwed it in, I could hear the propane burner start the roar.

Now I'm not sure where to adjust it to. I think I can take the tank in and have it adjusted at my RV shop. I read somewhere that the pressure should be at 11 inches of water column.

I'll report back with my results.

Thanks again for your help and ideas.

Phil

[modemem]

I was having problems with my fridge not cooling on gas even though the freezer was reaching zero. I pulled the unit out of the wall just far enough to tilt the top part into the hallway so I could remove the baffle in the chimney. After cleaning the baffle and chimney the fridge cools great and the freezer gets to about 15 below zero.

[wolfe10]

Phil,

I would STRONGLY recommend that you replace that old regulator-- they are under $25. Even if you use a manometer to set it, you are still working with very old gaskets/diaphragms. Not worth the risk with propane.

[desertdeals69]

11 column inches is 1/4 lbs pressure. Gauges are not as accurate as the water column

[audiophilepj]

Well....I ran the refig all night off LP. Woke up excited to check the temp, in the refrig was 24 degrees! Success! However, the thermostat (off, 3, 5, 7, max) was set to 5. So I decided to adjust it back out a little, 5 turns out. Today's outdoor high temp was around 80 degrees. When I got home and checked the temp, 70 degrees in frig. Well f&*% me sideways. So I adjusted it back in a little and it's cooling down again.

I think I'm going to take wolfe10's advise and buy a new regulator. I'm not 100% clear how regulators work, but info from desertdeals69, there are adjustable regulators, or water column regulators. I'm guessing water column are newer technology. Mine in probably from 92'.

I'll pick up a new one tomorrow.

A $20 regulator makes me a lot happier then a new refrigerator!

Thanks again for your info and support!

Phil

[dickandlois]

Phil, Water column is in reference to how the output pressure or gas flow is measured. Brett mentioned the manometer and this is the tool / Meter that measures the flow rate of the regulators and the standard is in inches of water. Like a air pressure gauge is used to check tire pressure.

Most gas regulators for RV appliances are set at 11in. of water or as DD mentioned about .25lbs of air pressure. Pressure gauges do not measure things very well at the low of a pressure.

Rich.

[audiophilepj]

I stopped by Jerry's RV on my way home to purchase a new regulator. After I told my story to Jim, he said it might not be the regulator. He recommended that I bring in the camper and have them test the pressure with a manometer. He said I could have cranked up the pressure so much that the 'low' setting is now over heating and thus cooling the fridge. He said my type of frig has a low and high burner settings. High for cooling, and low during idle. He thinks the idle setting is cracked way up. I guess I'll need to take the camper down to the shop after all.

I wonder if I can find info regarding testing the thermostat. Maybe with a multimeter....

I'll be back.

Phil

[desertdeals69]

Phil, Water column is in reference to how the output pressure or gas flow is measured. Brett mentioned the manometer and this is the tool / Meter that measures the flow rate of the regulators and the standard is in inches of water. Like a air pressure gauge is used to check tire pressure.

Most gas regulators for RV appliances are set at 11in. of water or as DD mentioned about .25lbs of air pressure. Pressure gauges do not measure things very well at the low of a pressure.

Rich.

A manometer will measure the pressure not the flow rate.

[dickandlois]

You are correct DD, but a pressure regulator setting of 9in. would reduce the flame and a setting of 13in. would increase the flame.

That to me means the pressure readings relate to the flow rate, so its a direct indicator of the flame size the way I look at the reading.

The regulator settings for the water heaters and furnaces set the flame size, where on a stove the burner is set by the burner knobs.

Placing a regulator with a 11in. pressure setting in the gas line of a grill before the flame control regulator that normally controls the low to high setting, will limit the flow so after reaching a flame size between low and medium, one can increase the setting to high and the flame size will not change in size.

Rich.

[desertdeals69]

When you reduce the setting of the valve, thus reducing the flow , the pressure before the valve is the same 11 inches of pressure, the flame is smaller. It is true you can change the flame size by changing the pressure but that is not how its done. The pressure will remain the same because thats the function of the regulator, which within the design limits (flow wise) of the regulator and the flame size is controlled by the metering orifice.

[dickandlois]

Thank You ! that fills in a gap, between the regulator and the orifice size; helps understand the relationship between the two.

Rich.

[audiophilepj]

One year later.... and I still haven't solved my problems. Not enjoying my entire camper packed with ice chests!

My local RV repair shop doesn't allow me to drop off just the camper. They need it on my truck (safety/stability), so I would be without transportation while they fixed it. So I planned on alternative method of transportation for a week, called up Jerry's RV to schedule an appt. They are booked out for a month!

I was leaning on replacing the cooling unit, but I wanted to confirm the CU was bad. I followed Dometics instructions:

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COOLING UNIT

To check the cooling unit, first verify the AC heating element is good. Then place approximately one gallon of water inside the refrigerator and place a thermometer in one of the containers of water. Supply 115 volts direct to the AC heating element and operate for at least 12 hours. Check the temperature on the thermometer. It should be at 45 degrees or lower depending on test conditions.

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After 24 hours, in hot 75 degree day temp, this morning the freezer is -10 degrees, and the refrigerator is 30 degrees. So I know for sure the cooling unit is working.

My next piece of hardware to troubleshoot is the thermostat. I still can't find instructions on how to test the thermostat. This is the thermostat. I'm thinking I will remove the thermostat and check any changes of resistance when temp changes. I can find instructions on testing a thermistor, but not thermostat.

Any ideas regarding the themostat?

Phil