Older fridge cooling Better on 110 than propane

NRALIFR: Well after about 24 hrs of running my refer at about 12.2" I'm at 48.7 deg F. So I turned my fans on and the temp went up to 50 deg. F. I give up, I quit. Maybe a new compressor fridge is on the horizon. Don't know but I gave it the "college " try, reached out to others, got some good info, got some condescending info, been accused of highjacking a thread, but I do know this, I've had it. Thanks for your help.

Wrong thread

Well, to be honest I don’t remember even looking at the static pressure. I would guess that it would be higher than 11.5”. I don’t really consider the static pressure to be significant unless you’re doing a leak check of the system. The regulator needs to have some load on it to regulate.

But, you’re in luck. I didn’t want to spend another day up on a ladder painting the house, so I gave myself the day off (I can do that since I’m the boss of just darn near everything around here, at least while SWMBO is at work). :B

It’s been almost a year since I replaced the LP regulator, and bought the digital manometer, so it was probably a good idea to check it again. As I said in the topic I linked to, the test port plug at the fridge is frozen and I can’t remove it. I twisted an Allen wrench into a pretzel last year trying to get it out and it never budged. After finding that the valve it’s part of cost $150, I quit trying to get it out.

This is the pressure with the fridge, furnace, water heater, and the generator running. I had the generator loaded about 50% using an electric heater. The pressure is about the same with the furnace off, and the AC loading the generator. The displayed pressure is actually bouncing around +/- .1 or so, but I tried to adjust the regulator so that most of the time it was above 11.5”.



And this is the pressure with nothing but the fridge running. Again, this is at the regulator. It might show slightly lower, and with less fluctuations if I could check it at the fridge. That’s less than one ounce per square inch difference between the two numbers.



Edit: Being an unapologetic OCD kind of guy, I started wondering if maybe I was checking and adjusting the LP pressure with too much load on the system. After all, the generator and furnace are both gas hogs compared to the other LP appliances. So, I rechecked things with the generator off, but all the other LP appliances running. The readings were virtually identical. In order to maintain 11.5” h2o with the furnace, WH, stove/oven and fridge going, the regulator had to be adjusted such that the pressure rose to about 12.7-12.9” h2o with just the fridge running. It is what it is, I guess.

:):)

NRALIFR: Wow! This is exactly the info I needed especially because it's to the point where my problem stems from and I will follow through with the regulator adjustment. I was leaning towards doing something like this and was looking for confirmation from people who have experienced this problem but up to this point, no one would come forward with this info.. Well, you're the man! I will post the results when I can. I'm really curious as to where the black stinky liquid comes from and is it an issue that needs to be addressed. Seems other people have mentioned it in the past. Just curious, what was your propane pressure after your final adjustment and with no appliances drawing from the system?

Yes, the LP pressure is too low. It should be adjusted to maintain 11.5” with most of the LP appliances going. In fact, I would try to adjust it for 11.5” with the furnace, water heater, and generator going. If it won’t adjust, you’ll need to replace the regulator.

Your regulator should be sized by the total btu’s of the LP appliances it’s supplying gas to.

Here’s a link to a topic of mine that is very similar to this one. You might find it helpful.

LP System Questions Topic

:):)

Okay so I tested my pressures. 11' with no draw from appliances. With the generator on it was 10". With the furnace on also it dropped to 9". With the refer on also there was no noticeable drop. I also tested the draw across the gas solenoid and it was 108.5 ohms. What say any of you guys in the know? Is there a problem? Also there is about a 1/2" clearance between the condensor and the wall. I know, it's excessive and I will take care of that but, again the unit works fine on ac and 12v.

Everyone and Doug, thanks for your help and I will at this point check the lp pressure from the regulator to the refer at the gas valve and dismantle the chimney looking for any irregularities along with a thorough cleaning of this area.

If your refer is working fine on 110 then there is nothing wrong with the cooling system. Something is wrong with the LP burner system.

Most likely, something is gunked/rusted up.

Possibly, there's something wrong with the gas supply.

Steve

ernie1 wrote:
I want to state this again and for the last time. The refer works fine and as it should on ac and as expected on 12v. BUT not very well on propane at all. So my thought is that the installation is proper otherwise it would not cool properly on ac. It is just the propane setting that won't cool properly. Again, my 2 friends have an identical refer and one also has a Dometic but a smaller model and we have the identical problem. So something is wrong that is common to these Dometics. Also I might as well say it loud and clear now, Dometic as a manufacturer is not worth a darn and has failed to correct this problem. Dougrainer, with your 40+ years of experience I feel you can do better than tell me that the chances of the wrong sized jets being installed on all three of these refrigerators aren't logical and that Dometic is blameless. What I expected from you was what the problem with these refers are. If the refers work fine on ac and 12v but not well on propane why is it a faulty installation? These are brand new units and Dometic via repair shops has been diddling with them to a point where they gave up and told the owners that the refers were operating as expected. Come on Doug you can do better.

I can do better? Remember, you are getting what you are paying for. There are 2 things that would make LP not operate as well as 120 volt. I am not getting into jet orifice sizes. LP pressure---after all these posts, have you VERIFIED the actual LP pressure AT the refer? The other is the condition of and IF installed the LP flame baffle. If it is missing and has been burnt/corroded, it will not disburse the flame correctly to heat the flue correctly to the right BTU. Sorry, I have a life other than these forums, and I do not go back and read ALL the previous responses. I missed the fact that the refer operated on 120 correctly but not LP. No I did NOT, I TOLD you to verify the LP pressure before doing anything else. NOW, I go back and found you hijacked the original thread. CHECK THE LP PRESSURE WITH A MANOMETER. THEN POST THE RESULTS;. I AM THRU WITH YOU. Doug

ernie1 my thinking goes like this!, usually the propane BTU on high is more than the 120v watts. if natual convection is enough for 120v it may not be for propane and causing areas that do not need heat getting heat!

What is your pressure? How far away from the wall is the condenser (baffeled?)