propane pressure regulator

[Iowa Dave]

Originally Posted by Bill and Earline

We adjusted my original regulator at Niagara last week, all as described in Posting #61.
It was Iowa Dave’s inherited manometer, with Carl W. assisting. I managed to loosen the plug at the fridge with RedDog’s socket—and I won’t be leaving my set at home again.

The first reading with no competing propane appliances, was barely 11, and with two burners lit, the regulator needed to be turned up (in,clockwise) to be a high 11 with the burners on. Otherwise it had slipped below 11.
Haven’t had any challenging temps since then and have mostly been on 120 volt, but fridge is great. It wasn’t really too bad before.
The newly purchased, and not used, H regulator is now part of my traveling stock, if anyone has a malfunction.
Bill

The manometer we got with our 21 is a yellow jacket. I will have it with me at the Mississippi River Rally. Attendees will be welcome to use it to check their water column pressure. You will need a good socket set in 1/4 or 3/8 inch. The fitting with the manometer is SAE and the test plug in the Dometic unit in Bill and Earline’s trailer was metric, about 11 or 12mm. I will not be loosening any fittings on trailers other than my own as my old barroom arm wrestling muscle memory could kick in at any time and that coupled with my lack of patience would not be good on a small propane line. I’ll be in site 114 with the manometer in my bug out bag along with sustenance should the economy go completely south. ( Read that a can of Spam, some candy and a couple airplanes). Why spend $50 bucks on something you can borrow. You CAN get by with a little help from your friends.
Iowa Dave

[bnjones173]

What is the effect if you have 15” with nothing running at the refrigerator port. It didn’t drop much with the water heater and 2 stove burners on

Should it be adjusted down or just left as is?
Thanks

[padlin]

I'm certainly no expert but if it were me I'd drop it down to 12". My system works great at 12", which is what the new regulator was set to when I installed it. 15 sounds substantially higher then it needs to be.

[rubicon327]

Originally Posted by padlin

I'm certainly no expert but if it were me I'd drop it down to 12". My system works great at 12", which is what the new regulator was set to when I installed it. 15 sounds substantially higher then it needs to be.

Agreed. Set to 12” w.c. and then fridge will stay above 11” when under reasonable load. 15” is too high.

[davidmurphy02]

A quick question regarding adjusting the pressure regulator. Can the plastic cap be removed and adjustments made with the gas on, or does the gas need to be turned off before removing the plastic cap?

[rubicon327]

Originally Posted by davidmurphy02

A quick question regarding adjusting the pressure regulator. Can the plastic cap be removed and adjustments made with the gas on, or does the gas need to be turned off before removing the plastic cap?

Gas on.

[davidmurphy02]

Originally Posted by rubicon327

Gas on.

That's what I figured - that plastic cap does not look like a gas seal. But never hurts to ask when you're not sure.....

I have a manometer on order and will be able to check my regulator pressure soon and find out if that has been my issue or if I need to continue to increase my furnace education. I am at least encouraged by finding in the Atwood tech manual that with the outside access door pretty much all of the serviceable / replaceable parts can be accessed without having to remove the furnace.

Sure hoping I find something funky with my propane pressure.

[Iowa Dave]

The plastic cap just covers the adjustment screw which on mine can be turned with a conventional flat blade screwdriver. Here’s how I do it. Shut the gas off. Remove the black plastic cap and insert a screwdriver in the hole and feel it drop into the adjusting screw slot. That way you’ll know how it feels and what “clock” position to look for. Then Access a point where the gas pressure can be accessed by removing a plug on a gas line, on ours it is on the Dometic refrigerator. Other setups might have different accesses. Put the manometer plug in and slide the hose on the fitting you just screwed in. Turn on the gas. The manometer will show the regulator pressure. Fire up your furnace and when running, Turn on and light all three burners on the stove. This will be at least 2/3 of a maximum draw on the system. If you can’t hold 11 inches pressure open the adjusting screw and watch the pressure go up. When it gets to about 11 with the stove and furnace running shut the appliances off. That should result in the manometer reading to increase to about 11.5 to 11.8. I’m running mine at 11.7 or 11.8 right in there. Shut gas off and try your appliances and see if it helps. I had a guy tell me that his regulator was too low to run both his hot water heater and his furnace at the same time. He would take a shower which made his water heater fire, Then he’d turn on the furnace to warm the trailer as he went to bed. Didn’t have enough gas to run them both but ok once he adjusted the manometer. Some people run varying pressures regarding elevation but I’ve not adjusted mine that way. I don’t spend much time at higher elevations. Others may have comments on how they do it especially for your model trailer and your appliances.
As long as you are methodical and logical and make sure to think the gas on/ gas off thing through, I believe you’ll be ok.
Iowa Dave

[C&G in FL]

If you have the propane QD option, you can get a male QD and fabricate a fitting that is easily connected and disconnected from the trailer. It is much easier than removing a plug to get access.

[Iowa Dave]

Good point Carl. I knew there must be an easier way. Maybe I need one for my lend out manometer kit.
Thanks
Iowa Dave

[davidmurphy02]

I will be very interested to see what my gas pressure is when I get my manometer. However, I don't have a lot of hope that low pressure will turn out to be the problem with my furnace - most of the time when it has failed during the night nothing else, other than sometimes the fridge, has been running. But even if it's OK right now at least I'll be set to monitor it in the future....everything breaks or wears out eventually.

[Kingfish]

Since the fridge test port is upstream from the fridge valve, wouldn't the pressure at the fridge test port be the same as at pressure regulator test port? Is it safe to assume that the pressure measured at the regulator test port (or the fridge test port for that matter) should be the pressure for the entire system prior to entering any appliance?

My fridge (RM8551) is functioning poorly on gas. Pressure was only 5 column inches at the regulator and wouldn't adjust. New Marshall MEGR-253 on the way.

[Iowa Dave]

Your logic is sound, same pressure throughout, a
Your solution will most likely work. I’ve adjusted several and even at 700 feet above sea level I like 11.8 inches.
YMMV.
Iowa Dave

[Kingfish]

11.8 without any other appliance operating?

[Iowa Dave]

If you set at 11,8 with nothing running, you’ll have adequate pressure for the refrigerator even when you’re cooking on the stove, with the furnace kicking in and out on a cool October evening or if nothing else is running any other time. When we’ve adjusted some regulators we light the stove, turn the stove burners wide open and then adjust to 11.8. WC iIt seems to give you a strong flame on the refrigerator all the time and it doesn’t blow out as easily and is good at higher elevations. That’s been my experience.
Iowa Dave

[rubicon327]

Originally Posted by Kingfish

11.8 without any other appliance operating?

Yes. I have found that 12” w.c. is perfect to keep the pressure above 11” when you have other appliances running. The correct procedure is actually to test with a demand of 50% of the connected BTU’s but as long as you have the furnace and a couple stove burners running you’ll be close enough. Although if you have something with high demand like a fire pit that you run off a propane quick connect you should account for that too.

[Kingfish]

Oddly, when I kept turning up the pressure on my current 7 year old Marshall regulator it eventually made it to almost 10 water column inches, and would go no further. It took many complete turns. So at 10 inches I tried the stove and now have zero gas pressure. Pressure was checked at the regulator port.

[SRS]

Originally Posted by Kingfish

Oddly, when I kept turning up the pressure on my current 7 year old Marshall regulator it eventually made it to almost 10 water column inches, and would go no further. It took many complete turns. So at 10 inches I tried the stove and now have zero gas pressure. Pressure was checked at the regulator port.

I read some place that RV propane regulators only last about 6 years. They have a diaphragm inside that can become stiff with age or crack. The diaphragm adjusts the output pressure based on atmospheric pressure. I've found on my 2022 E17 that the easiest place to check propane WC is at the frig because there is an easily accessible gas port there. Testing at the appliance is IMO a better since it's downstream from the regulator so you're measuring the actual pressure the appliances are getting.

[Iowa Dave]

Some Dometic refrgerators have a test port and some do not. Our 2010 19 2510 model had one. Our 2013 21 has an 8555 and it does not. If it were me I’d get a new regulator and two full
Propane bottles. Hook up new hoses, slowly open both bottles, check for leaks, set the pressure as described. Turn off the indicated bottle and see if it changes over like it should if you run that way and figure I was good to go.
Iowa Dave

[SRS]

Originally Posted by Iowa Dave

Some Dometic refrgerators have a test port and some do not. Our 2010 19 2510 model had one. Our 2013 21 has an 8555 and it does not. If it were me I’d get a new regulator and two full
Propane bottles. Hook up new hoses, slowly open both bottles, check for leaks, set the pressure as described. Turn off the indicated bottle and see if it changes over like it should if you run that way and figure I was good to go.
Iowa Dave

I'm sure that's true and my water heater doesn't have a test port either, at least not one I can find. When I was having frig problems I got this adapter from My RV Works which allows me to tap into the flared gas line hose fittings. Really easy to use and it has a quick connect at the end of the flexible tube to connect my digital manometer and the yellow handled valve allows you to bleed off propane to simulate the effect of another gas appliance running at the same time (don't do that around an open flame).

It's a little on the expensive side but the hourly charge at the local RV repair shops is $200/hr so instead I got a nice tool I can use in the future. More importantly, when I had frig problems, the repair shop never thought to check the gas pressure. My frig wouldn't stay operate consistently on gas because the regulator was putting out 14" WC. At 12" WC it's bullet proof.