Odd propane behavior - starts out ok, then gets weak...

[brucemc]

Thanks for the info on your experiences, dbledan. We'll have an appointment with the dealer as soon as I call them; I'll let everyone know of the outcome.


In the mean time, I've purchased yet another new regulator with factory installed pol nut, and installed it on one of my older grilling bottles that I'd just had refilled.


With either the factory supplied bottle, regulator & pigtail, or my Sunseeker regulator, or the new regulator:

With the connection to the WH corrected, the WH runs w/o issue.
The furnace runs fine for a while, then the flame changes to a jittery mess that looks like the gas is actually burning in the chamber but away from the burner tube, but it's still putting out heat. I'm not sure that it is supposed to do that as I would expect to see the same flames from the orifices in the burner tube throughout the run. This is concerning to me.
After fixing the leaking connection in the WH, I heard the odd noise from the furnace one more time, but have been unable to reproduce the noise since then. My son ran some test cycles last night in preparation for the warranty visit, but hadn't yet reported his findings.

Next, the stovetop is still behaving the same as it always did - it'll run fine initially, but 5-10 minutes into the run, the flames start shrinking and changing to orange tips. The stovetop has an additional regulator within the unit, so it's possible that regulator is faulty.



Perhaps there are/were 3 distinct issues: WH connection, Furnace issues exacerbated by the loose fitting in the WH, and the consistent stovetop issues.


I've bubble checked all fittings and have found no other leaks, as well as checked the tightness at each fitting. There's nothing in the lines - they are all clear as the day they were installed.

[brucemc]

It would appear I never followed up on this post... Sorry about that!
The dealer went through the system and found:
1) The regulator was putting out 11" WC with no appliance pulling propane; it would drop below 11" as items came online. This was the main cause. The tech cranked up the pressure so it would not drop below 11" with all appliances drawing propane; static pressure was 11.5", if I recall.


2) The furnace plenum was full of stink & box elder (alder?) bugs. We've been having an invasion of stink/shield bugs the last couple/three years, so suspect they made their winter home in the plenum. we couldn't see the bugs from either the intake or exhaust ports. The tech used compressed air to work the majority out. I'm not sure how he identified the issue, but it certainly shows he is experienced in such matters.

I wondered why his furnace exhaust smelled like a pizza when he first brought it home. Yes, it smelled like a cooking pizza!

It still runs for a while then will make those gurgling sounds, tho not near to the extent they were. The tech stated that was normal for those units. (I don't know the brand/model right off hand)


3) The stovetop works properly with sufficient pressure - no further issues other than a shutoff stop problem, which was unrelated to the supply issues. One burner would often not go out, but would leave a very small spot of dancing flame around the burner. The tech adjusted the stop so it would shut off completely.



I still find it odd that we saw the same weakening flame symptoms with the regulator out of my Sunseeker, but we never see those issues in the Sunseeker - and we have a 3 burner stovetop + oven, and a much larger furnace. It's possible our horizontal tank has better flow then the 20# bottles.



But no matter - all is well now.



If someone else is experiencing similar issues, have the regulator checked for 11" WC when all is running, and (literally) check for bugs in the system!



Again, thanks everyone for your valuable input!

[Bama Rambler]

Thanks much for coming back and letting us know what was found and how it was found and fixed. We have infestations of Asians Beetles from time to time, but I never thought about them nesting in the furnace.

[TitanMike]

Originally Posted by brucemc

If someone else is experiencing similar issues, have the regulator checked for 11" WC when all is running, and (literally) check for bugs in the system!



Again, thanks everyone for your valuable input!

Acceptable range for gas appliance (LPG) pressure is 10"-12" W.C. Everyone focuses on 11" because it's in the middle.

One thing that is important, but I didn't notice in your post, is that if you can't maintain 10-12" W.C. with all appliances operating, your main gas line to the distribution "manifold" is undersized, kinked, or pinched. If one adjusts the pressure to 11" WC with everything operating, it will normally rise when they are shut off to what's called the "lock up pressure". This should not be more than 30% more than the flow pressure. If there is a huge differential between flow and lock-up pressure, there's a huge chance your gas line is undersized, kinked, or pinched.

Doesn't take much of a restriction in the typical 3/8" line from the regulator to cut down on flow. Start adding up BTU Ratings for Furnace, Stove, Water Heater, and chances are you are at the limit of flow capability, especially when taking into consideration the distance from regulator to first connection on distribution line.