Not Enough Cooling on Propane

[TankerIP]

I I've been dealing with a frig that works very well on AC but poorly on propane. I measure activity with one of those infrared thermometer detectors. On AC, right above the flue, the pipe measures 305 deg. On Gas the same measure is 218 deg. Clearly the system is not getting hot enough on propane to really cool the Frig.

I have a 2452 Dometic Americana. 2-way. Piezo lit fire. 2002 Airstream

The flame looks good (blue). The needle is barely in the green. The gas pressure at test inlet with flame lit is 11" WC.

I spoke to an Airstream @ Jackson Center that said gas cooling ability of all Dometics reduces overtime. I wonder why? Even if i bought a new one, he said, that overtime the same would happen. Hmmmm? Does anyone understand this?

I have cleaned the orifice a few months back and will try that again. I have cleaned the burner by taking it out and shaking it.

I wonder about the burner flue? Where can you buy a flue brush to clean that out?

Any Ideas

[CRH]

My prior trailer was a 1974 with the original fridge. I sold it in 2014. It still would freeze food on the coldest setting. Same for my 1995 and it's original fridge.

[68 TWind]

Have you check the condition of the flue? Over time, it can get dirty and rusty and that may be the reason you were told that over time efficiency can decline- just a guess.

You already checked the pressure and know it is not the problem. I had a similar situation a few years ago, poor cooling on gas. After a lot of trouble shooting I found a dirt dabber nest on the bottom underside of the pressure regulator blocking the little screen. I cleaned it off and all was well.

[TankerIP]

Here's what I did today:
1. Removed orifice and soaked in Ethyl alcohol for a while. So I just blew through it, resoaked and inspected with magnification. It appeared to have a clear hole.

2. Removed flue baffle. I do not have a flue brush, but I did use a flexible, plastic coated wire to run down through flue. No obstruction. Reinstalled baffle.

3. Measured pressure again at test port. Started fire. Pressure was exactly at 11". Possibly would like a higher pressure but could not figure out how to adjust pressure with the kind of regulator I have.

4. Tested temperature at tube rising from flue heater area. This time I got 280 deg. Somewhat more than yesterday. I will check again later and see if operation has improved. We leave out tomorrow for Jackson Center. So I will have a chance to test on the road.

[68 TWind]

thanks for the report
Good luck and safe travel

[ventport]

I had the exact same problem, Bought a new regulator and the fridge worked perfectly. I checked the gas pressure and it was 15 instead of 11, so I re adjusted the regulator. With the regulator set at 11 I was back to no cooling. I turned the regulator back up to 15 like it was set from the factory and the fridge works perfectly. So that is where I am leaving it.

[starboard]

You can also check if you have any "oily liquid in you propane pipes, it accumulates over the years and it is easy to drain. I had a similar problem with my tankless water heater and since I drained the system everything from fridge to water heater and stove works better.

[MelGoddard]

Originally Posted by ventport

I had the exact same problem, Bought a new regulator and the fridge worked perfectly. I checked the gas pressure and it was 15 instead of 11, so I re adjusted the regulator. With the regulator set at 11 I was back to no cooling. I turned the regulator back up to 15 like it was set from the factory and the fridge works perfectly. So that is where I am leaving it.

Where is this regulator, and how does set it?
I have a 2016 30' FC.

[ventport]

The regulator in the first thing the rubber hoses that come from the LP tanks hook to. On my regulator there was a quarter size round black plug that unscrewed. The plug covered a slotted screw that I turned in to increase the LP pressure. Make sure you have a pressure gauge, so you know how high you are setting it. I hooked my pressure gage to the stove to get a reading while the fridge was running.