LP Pressure Regulator failed again???

[KitsapEra]

This is for a 2018 Winnebago Era with a 2500 watt Onan LP generator, Truma Combi and LP stove.

I noticed on the last trip that the generator was balky and hard to start or would die after running a bit. Decided to go ahead and check the oil.... Only to have the plastic screw top at the top of the dipstick break off in the hole! Ended up having to drill the remaining pieces to get them out, which of course meant that plastic bits went down into the oil pan. So then I set out to change the oil... Only to discover there is almost no space under there to add oil. Had to improvise a funnel and tubing setup to be able to put a quart of new oil in. Started and ran it briefly, then drained that oil and added new oil again. Unfortunately, no visible bits of plastic came out, so I suspect all the bits are still in the oil pan. Then went back to trying to start it. Same problem - it would run briefly and then die when the load switched on. Discovered that the gas pressure was going from 11WC to zero when it died (glad I installed a LP pressure gauge last spring). So at this point I'm thinking that the two-stage pressure regulator that I installed in April already has a problem. The strange thing is, it seems to supply pressure for the stove and Truma*furnace just fine. Last time around I just had no usable pressure, so nothing worked.

The regulator I installed in April was supposedly compatible and rated for like 350k BTU, which should be more than enough, but right now I think I am looking at my second failing regulator in a year.

Any ideas or suggestions?

-dm

[Morich]

Sounds unlikely but then new things do break and try to confuse us!
I might favor looking at checking the pressure coming out of that reg before trading it out again.
Any chance you have a local propane guy that would know about that for a few dollars?
Since propane is not one that I work with enough to feel I know enough, I might call in the folks who do??
Sometimes testing has to be done with the right gauge and the right guy to know what it means, for sure.

[KitsapEra]

Originally Posted by Morich

Sounds unlikely but then new things do break and try to confuse us!
I might favor looking at checking the pressure coming out of that reg before trading it out again.
Any chance you have a local propane guy that would know about that for a few dollars?
Since propane is not one that I work with enough to feel I know enough, I might call in the folks who do??
Sometimes testing has to be done with the right gauge and the right guy to know what it means, for sure.

The gauge I installed is on the output of the manifold, same as the line to the generator and all the other LP appliances.

I actually do have a spare regulator that I had bought on Amazon last spring - I didn't use it as it is only rated to 160k BTU and the RV parts place I went to claimed I needed bigger than that for the generator. But from Googling, it appears that a generator should only really require about 10k BTU per HP, and a 2.5Kw generator should be in the range of < 10 HP (really only about 8) so I'm going to try the regulator on got on Amazon tomorrow.

[Morich]

Jet me check if I am actually getting what you are doing?
You have a gauge just before the generator to measure the gas pressure and it goes to zero when the generator is running and then the generator dies?
Since the regulator is meant to keep the pressure steady under all conditions, that certainly does sound like the new one has failed!!
One odd thought might be if the pressure comes back up after the generator has died
? That might say the gas line and new reg are not passing the enough gas volume to keep the line filled to let the gen. run?

Might want to double check the reg is correct for both pressure and amount of gas it passes?
Not really gas trained here, so just thoughts to pass think over?

[KitsapEra]

Originally Posted by Morich

Jet me check if I am actually getting what you are doing?
You have a gauge just before the generator to measure the gas pressure and it goes to zero when the generator is running and then the generator dies?
Since the regulator is meant to keep the pressure steady under all conditions, that certainly does sound like the new one has failed!!
One odd thought might be if the pressure comes back up after the generator has died
? That might say the gas line and new reg are not passing the enough gas volume to keep the line filled to let the gen. run?

Might want to double check the reg is correct for both pressure and amount of gas it passes?
Not really gas trained here, so just thoughts to pass think over?

Yes, shortly after the generator starts the pressure drops from what it should be, 11WC to around zero. Sometimes it bounces around a bit - which causes the generator to surge, but then the pressure goes back to zero. As soon as the generator quits entirely, it returns to 11WC. As confirmation that the pressure is going down, we lit the stove one time before starting the generator, after attempting the generator start the stove was no longer lit.

I had replaced the regulator in April with a new OEM one: https://www.amazon.com/Capacity-Stag...815715&sr=8-13

400k BTU. Before doing that, I had ordered a cheaper one (only rated at 160K BTU) from Amazon. I'm going to swap the cheaper one in it today. Despite the insistence of the guy at the RV repair shop that I should use the OEM one, it does appear to me that 400K BTU is overkill. A 2.5KW generator implies a 5 to 8HP engine, and this site:
https://www.primalsurvivor.net/propa...on-calculator/

implies you only need about 10K BTU Per HP.

The gauge I got off of Amazon, and it is installed directly into the propane distribution manifold (there was one spare port). What is strange to me is the fact that it seems to supply enough LP for the Truma and stove (both at the same time) but the generator kills it. The April failure resulted in the Truma and generator not starting, and only a very tiny flame from the stove.

BTW, the generator worked fine after the current regulator was replaced, and I just noticed an issue last week while checking it before our most recent trip. It was hard to start then, but would start and run until the load was turned on, which would tend to cause it to die (most of the time). As of yesterday, we've progressed to a situation where it dies within a few seconds of startup.

If the OEM regulator failed again after just 12 days of camping this year, I'm going to be really pissed - but OTOH at least it is a failure I can diagnose and fix myself. It is really masking a generator issue, I'm in trouble. All the shops around here tend to be scheduling many months out!

Thanks

dm

[Morich]

Definitely know where you are on understanding some things but lots of things that are still a big question and getting service is really hard right now. Apparently letting a bunch of people die is not good for business--especially if they are the real workers who do the stuff we need?

Just top of the head guessing, it almost sounds like the generator has something wrong that lets way to much gas go someplace it should not, rather than being used to run it, then when it shuts down/dies the flow stops?

Wild theory and not worth too much!
Sounds like a point where we have to jump one way or the other and without knowing which way!

[KitsapEra]

Sure enough, swapping in the backup regulator I had seems to have cured the issue. Have to add this to the list of "weird symptoms when a regulator is failing". Also need to order a new backup one. For the record, the Marshall Excelsior one that I installed is only rated at 160k BTU, but seems to be capable of handling the generator and stove simultaneously. The OEM MB Sturgis regulator is rated at 400k BTU, and according to a neighbor (who is a HVAC pro, but not an RV guy) massive over-kill for the load in the Era. Having had to MB Sturgis regulators fail in 6 months, I'm going to try the Marshall for awhile.

-dm

[coachmanjay]

Could be there is a solenoid valve that closes on high flow 400k thinking it is a leak Also a lot of generators run on high pressure propane, if using a two stage regulator toy are not getting enough flow. Stoves, fridge etc Ron on low pressure 11”WC

[Lmonger]

Maybe check Generator ignition coil?

[TravatoJohn]

If you are ever in Alb. New Mexico there is a great propane guy at the Enchanted Trails RV park. He’s out front in a trailer and opens around 9am. Everyone sends there problems to him. Just an FYI. Travato John