Caution: Propane gauges blamed for furnace ignition failure

[jcurryii]

Originally Posted by margerush

bshgto: we have the propane monitor (Tank Check LP with Monitor Kit) on our tanks--they didn't work for us. LP tanks were empty but the monitor said they were full. The bottom of our LP tanks are rounded where we stuck the "guage". Since the bottom of the tanks are rounded, is this why the monitor didn't work?

All tanks that I know of have rounded bottoms. You may have to reload app or you may have a defective set.

[northern lights]

" have never run out of propane and have never used a gauge. I just keep one tank closed, and if i run out of propane in one, which I did once, I would then turn on the other tank, and get the first tank filled again..."

Occam's Razor usually provides the answer.

[holbrook2]

Originally Posted by RookieDCB

I have been having intermittent problems with the furnace recently, and thought I would share my experience and the solution (fingers crossed).

The Problem
Intermittently, the furnace would fail to ignite. The problem seemed to occur on the coldest nights, in the wee hours. We would wake to temps in the low 60's in the coach. I could sometimes nurse things along by turning off the thermostat, waiting a few seconds, then turning it back on. However, that proved to be only a temporary solution. While the furnace might run for a few more cycles, it would ultimately fail to the point where nothing I could do would get it going again, and we would just have to endure the early morning cold with the fireplace as the only source of heat until daytime temps warmed to the point where the heat pump could be used.

With benefit of daylight, and some hints from this site and others, I removed the outside furnace panel to see what I could find. The red light blinking pattern indicated an air flow/limit fault. (I could not find a clear, authoritative explanation for the potential causes triggering that error and possible solutions.) Sometimes, when ignition failed, I could turn the furnace switch off, then back on, and it might ignite for a few cycles. I think that was basically accomplishing the same thing as turning off the thermostat inside, then turning it back on. Either method would only work temporarily, then nothing I could do would get the furnace to light.

Based on information on this site and maybe elsewhere, I wondered whether our use of magnetic covers for some of the heat registers was contributing to the problem. We stopped using them, but the intermittent ignition behavior persisted. (To conclude this particular rabbit trail of thought, the service manager later told me using a cover or other method to restrict output from a register had nothing to do with the problem, and it is perfectly alright to use them.)

Nothing else obvious stood out. There was plenty of propane on board. Switching tanks accomplished nothing. Stove burners operated fine. When we took it in for service, the mechanic could not get it to fail (of course). We took it back to our site, and on the next cold night it failed (of course).

The Solution
Back to the servicing dealership for a second visit. This time, the service manager (who was out for a doctor's appointment on the previous visit) noted we had gauges on the tanks similar to the one pictured. (Note: The image is from a Lowe's product, but ours were not purchased there. Just using it as a representative example.) His experience over many years with such gauges is that they cause more harm than good by eventually restricting the flow of propane. He removed the gauges. Since then, the furnace has been working fine. It hasn't yet been 24 hours, so if something changes, I'll update this post. But we made it through a cold night last without any issues -- and used the magnetic register covers.

I'm posting this because others may want to be aware of the potential issues with these propane gauges. We're just getting started with our RV adventure, and we made it through a few weeks before the problem described above began. Looks like we'll toss the gauges and use more rudimentary methods to determine the levels of propane in our tanks.

Thank you for posting this. We have had no heat since we left home in PA the day after Thanksgiving. Husband could not figure out why. We are in 2018 Montana. We called repairman but he never showed up. Currently we are in Bushnell, FL for the Winter. So, yesterday we get the Montana Newsletter and first article has to do with our heat situation. I read to my husband and yes, we had the gauges on our propane tanks. He went out and took them off, and now we have heat! Such a simple fix! Thank you!!!!

[bshgto]

Originally Posted by margerush

bshgto: we have the propane monitor (Tank Check LP with Monitor Kit) on our tanks--they didn't work for us. LP tanks were empty but the monitor said they were full. The bottom of our LP tanks are rounded where we stuck the "guage". Since the bottom of the tanks are rounded, is this why the monitor didn't work?

Yep, from what I`ve read if you have a rounded bottom the sensors have trouble reading the gas. I have no trouble with mine and I have flat spots on the bottom of the tanks, they are pretty accurate so far. I like them for the price.

[davidksallee]

I was considering gauges for the 2 -30gal tanks on our new 2018 HC 321. Ask the LP store guys busy filling up 30 gal tanks at $13 per tank in central TX about tanks with gauges and he said they wont carry them to sell, didn't work and caused too many problems. His suggestion same as salesperson and many on thismthread, just fill one tank as soon as empty. Iam carrying a 20 gallon spare in ventilated front compartment for grill n back up.

[jimcol]

Originally Posted by davidksallee

I was considering gauges for the 2 -30gal tanks on our new 2018 HC 321. Ask the LP store guys busy filling up 30 gal tanks at $13 per tank in central TX about tanks with gauges and he said they wont carry them to sell, didn't work and caused too many problems. His suggestion same as salesperson and many on thismthread, just fill one tank as soon as empty. Iam carrying a 20 gallon spare in ventilated front compartment for grill n back up.

Dave, Just an FYI, the tanks are pounds not gallons.

[davidksallee]

Thanks, senior moment

[MaxwellD]

My 2018 3730FL has a propane regulator with a selector switch which I thought would provide automatic changeover to the full tank when one was empty. My first fiver was SOB and had automatic changeover regulator which worked flawlessly. The one on this Montana gives no indication that one tank is empty and drawing from the other - it is only - BAM, you’re out of propane. Could my regulator be faulty?

[Wyatt Earp]

We bought our unit in April and never needed the furnace until our Thanksgiving trip. When we fired the furnace it sounded like a jet engine. We ran it that way for three days until the night before we left, had to turn it off. The sound changed and was very mincing. Took it to the dealership thinking it was warranty work to find out mice had build a large nest on top of the furnace, water heater and even into the blower blades. We now have several bait stations located inside the camper. Checked on them this morning and the mice are enjoying the free meal.

[Pitchbb9]

I have had the same issue with my furnace
I have 30000 btu furnace in my 2010.
The temperature at night was only in the 30’s. All my research found that propane flow isn’t effected until it gets very cold.
I have a Fairview dual tank regulator and on each side the hoses are connected to inverted flare fittings that have back check valves in them. These valves were failing.
This easy fix to a frustrating issue. Hope this helps.

[DCB]

I’m the author of the original post in this thread. Just a quick report that the furnace has worked flawlessly for the last week. I guess the service manager knew what he was talking about. Thankful for a happy outcome!

[Rondo]

We have the gauges that RookieDCB has posted on his thread on both of our tanks and have had no problems at all with our furnace igniting or running. I do know one thing about these gauges and that is they do not register unless there is propane flowing from that tank. If you have it turned off or it is not being used they will not register an accurate reading.

[DCB]

"This time, the service manager (who was out for a doctor's appointment on the previous visit) noted we had gauges on the tanks similar to the one pictured. (Note: The image is from a Lowe's product, but ours were not purchased there. Just using it as a representative example.) His experience over many years with such gauges is that they cause more harm than good by eventually restricting the flow of propane. He removed the gauges. Since then, the furnace has been working fine. It hasn't yet been 24 hours, so if something changes, I'll update this post. But we made it through a cold night last without any issues -- and used the magnetic register covers."

Another update from author of original post:
We have been using the furnace successfully as described above for 12 days/nights. Last night, the furnace began acting up again. The fan cycled on for about 2 minutes when the stat called for heat, but the furnace did not ignite. Propane regulator showed green. Lifted supplying tank (tank #1); it was about 1/4 full. Lifted tank #2; it was full. Turned off tank #1, and pointed regulator to #2. Lit oven. Turned up thermostat to call for heat. Furnace ignited. Worked until about 3:30 a.m., when I was awakened by cold. Coach was 59 degrees. Thermostat set at 69. Lit oven. Furnace would still not ignite. Used electric fireplace and heat pump for the rest of the night.

Tried getting furnace to ignite this morning by raising thermostat setting, and turning it off/on. Furnace fan would kick on, run for about 2 minutes, but no ignition.

Theorized the sail switch is faulty, so started reading up on that. May still be part of the problem, HOWEVER, I decided to test another theory before opening up the furnace. One at a time, I uncovered registers that had magnetic covers, then turned on thermostat. Furnace behaved the same for registers 1 and 2 -- fan ran for about 2 minutes, but no ignition. With register 3, fan ran for about 30 seconds, but no ignition. I then uncovered all three. Furnace ignited and ran for one cycle. However, when stat called for heat again, fan ran for 30 seconds, but no ignition. That's where we are at this very moment. More experimenting to come. But, this begs the question of whether the register covers are part of the problem, despite what the service manager said...

[Bierp]

I'm in a similar boat. I'm getting the airflow alert as well. Once in a while I can get it working, but most times the fan runs but it won't ignite.

I took it to a dealer for warranty work last Friday. They 'cleaned and lubed' the sail switch and sent me on my way. It worked for two days, but by Monday night it was failing again.

I do not have LP gauges on, just the manual selection regulator. The stove works flawlessly.

I can't see how the gauges would cause an airflow fault though. Wouldn't that throw a flame fault?

My concern is that the installation manual for this furnace is very specific about how to mount the vents opposing one another and how to absolutely not use 2 inch ducts. My unit has 3 ducts, two of which are 2 inchers and all three are on the backside of the unit, rather than opposing each other.

Does that impact airflow? I'd imagine it does, but I'm definitely no expert.

Keep posting your updates here. I'll let you know if I find a magic bullet as well. Good luck!