Furnace problem

[sreigle]

The problem seems to be solved although I'm not positive what caused it in the first place. Our dealer gave me both regulators. I switched out the little red one. No change. Switched out the main regulator. No change except that the indicator stayed green regardless of tank it pointed to. The old one would show a little red, mostly green, when pointing to the opposite side. However, my indoor indicator still flashed when the regulator pointed to the off side.

On our prior Montana the main regulator was on the door side cabinet but on this Montana it is on the opposite side. On both Montanas I had the external bottle connected on the door side. On a hunch that maybe there's something about pressure differential at work I moved the external bottle and the connections to the side with the main regulator. Problem solved. Everything works and the inside indicator isn't flashing.

I don't understand why it works but at least it is all working.

Thanks to all for the help.

[jkbeaudin]

For what it's worth, I have had problems with an intermittent failing of a similar RV heater on my travel trailer of several years ago. Never did solve the problem - but the furnace would work fine in mild temperatures and then go on the blink at very low (freezing) temperatures - I was sure there was water in the propane line some place - but sold the trailer before finding the solution. On our more recent FW (a Sunnybrook just traded in for a 3400RL), I purposely did not use the automatic cross over propane switch. Because I completely ran out of propane in both tanks!

Now I know when a tank is empty and I go outside and manually flip over the switch myself.

Funny how sometimes the new gadgets don't work for everyone. 'Cause I still like the old manual method, so I know to get the empty tank filled.

Jim & Gayle (recently retired) & Cocoa & Brandy (always retired Brittanys)
2007 3400RL nicely loaded
2005 Dodge Quad SB 3500 SRW Cummins Auto

[sreigle]

Gee, I sure hope we don't duplicate your freezing temperature problem!

[Mudchief]

Sreve, I hope you don't have that problem either. It shure would be hard getting out of bed at 2 in the morning to switch that valve.

[Mudchief]

Sorry Steve about your name and the word sure. I guess my fingers were getting cold thanking about that.

[noneck]

Hi Steve,
I don't know but sounds to me like the driver's side feed may have reduced flow causing the auto switch over to not have enough delta pressure to flip completely and/or starves trying to keep pace with the furnace flow demands. I wonder about that "little red regulator"... I bet now that you moved the 100lb tank to the curb side (now you have to look at it) has fixed your problem.
Chuck

[Wrenchtraveller]

It was the driver's side tank that I had to move to the auto switch side when I had my problem and Noneck's theory is probably right.

Is Montana the only RV with a tank on each side of the unit? Perhaps the switchover valve is more reliable on side by side tanks and the next time I am in below freezing weather I am going to draw from the curb side when I need my switch over valve to work for me.

[rvfirefighter]

I have a new problem with my furnace this morning. I am in GA. the temp. is 27 degrees. My furnace will not stay on for a long period of time to warm up the RV. I slept with the thermostat on 50 all night, when I got up I increased the temp. to 60 and the furnace will not run but approx. 1 minute at a time. The temp. is just 52 in the RV.
Any Ideas out there that might explain what's going on?

[Ozz]

Check for restricted airflow, sounds like it's cycling on the high temperature safety.

[rlrich]

This may be unrelated but it is a problem I encountered that involved the whoosh - whoosh sound. I was checking things outside during a furnace burn cycle and noticed this whoosh sound at my propane tank. I would normally hear the steady hiss of propane moving thru the system during any usage of propane in the trailer. After doing some research on propane, I learned that one of the natures of propane is that it has some type of oil in it. Cheaper grades involve more oil or something. Anyway, I removed the rubber gas line between the regulator and the steel lines running under the trailer, which luckily had a low point sag in it, and guess what came running out - a light oily substance. Enough had built up that the propane was evidently "gurgling" thru the oil causing the whoosh sound. I let the hose drain for a couple hours and reassembled everything. No more whoosh sound and a nice steady hiss of propane moving unrestricted thru the system. I now remove this hose regularly and drain it. It always has at least a few drops in it. Imagine the damage this oil could do if it were to make it to our propane burning appliances.

Just a thought.

[bsmeaton]

rl -

Very good point! I had problems with my generator and took it in to Cummins for repair. He pulled the feed line and oil ran out and he laughed. He said I need to watch where I buy propane. He turned on each tank and let the LP pressure blow out the feed lines and pulled the low point drain. Generator ran perfect after that!

I also suspect oil was the cause of my last regulator/auto changeover valve failure. I think the oil causes problems with the changeover valve.

[Ozz]

Hey David, are you still having problems?

[Charlie]

rlrich-
Most likely the oil in your propane system came from the same place that mine did. I replaced a regulator before I found the oil in my system. There is no concrete proof, but what I saw appeared to be thread cutting oil that was left in the 3/4" crossover between the tanks. I suspect the vendor that is cutting pipe for installation is not properly cleaning the thread cutting oil. Others here on the forum have had similar experinces with oil in the propane system.

The properties of propane DO NOT allow it to have oil in. It is a clear liquid under pressure at about 180# that completely evaporates at -35F. If there is any oil in it some one messed up big time somewhere in a refinery and contaminated the propane, and that can happen, but not most likely so.

The only thing that is added to propane is for safety purposes as propane in it's pure state is basically oderless. What is added to propane to give it smell is known as "stench", it is a sulphur related compound known as Methyl Mercaptan and in it's pure state smells like rotton cabbage.

[snfexpress]

Update on my furnace problem. My furnace would only activate the blower, and it wouldn't turn off, unless I removed the fuse (#6 12 volt), or turned off the switch on the unit, itself.

I replaced the circuit board and then found that it wouldn't always ignite the propane, causing it to lock out after three attempts to light.

I took out the furnace (Keystone obviously missed this in their engineering design) which took about 30 minutes (third time out of the cramped space in the basement). I had ordered and paid for an ignitor from Atwood, and it took me over an hour to replace the ignitor! Finally, I got the old one out and the new one in, and after re-installing it, the furnace works as it should.

FYI - when bench testing the unit, make sure the exhaust tube is inserted. Atwood states that without the exhaust tube in, it will attempt to ignite, but will then turn off. Wwithout this knowledge, one might think that the unit is not performing properly.

[Rozeboom]

Anyone have issue with blower running all the time even with thermostat turned off

[Carl n Susan]

You might have a better response by starting a new thread for your question. This Thread is 14 years old and probably a little dated.