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BFL13's avatar
BFL13
Explorer II
Oct 25, 2017

Propane Woes Question

Another question about the propane from the big sideways tank in a Class C.

After we bought this rig recently, turned on the propane tank gas valve, and had a heck of a time getting the appliances going. Eventually, I did get them going, so I thought we were in the clear.

Shut off the big tank and drove up to the scales and around a bit and back and parked back at home. A few days later, today, turned the big propane tank on again and all that would work is the stove top burners. After a while, I got the fridge to work on LP. Swearing helped I am sure! But still no hope with the previously working ok water heater and furnace.

After some more time and swearing the water heater decided to work ok.

I finally got the furnace to work. The fan blower part was going great from the get-go but no heat. This went on for a few hours while I monkeyed with the thermostat and so forth (more swearing, but to no avail)

I then pulled a wire off a black switch over to the left, which stopped the blower and then re-attached the wire. Blower came right back on, and after a bit there was a click and a smell of gas. But no ignition. Did that some more times and eventually it fired up. Hooray!

But then it seemed to stumble a few times (I am suspecting air in the line of course) and eventually ran well and true.

So now all the appliances are happy and everything seems ok. BUT!!!

We don't want to drive to the campsite with the propane on. The big worry now is if this whole agony will repeat itself when we get there and turn the big tank valve back on. Will the appliances work or not? Or will we have to fool around for hours like this time? Yipes!

Is it normal for air to get in the lines between tank shut- offs like that after a few days? If so, can you hope the appliances will fire up ok if you turn the big tank back on after shutting it off ---that same day--- after a drive to somewhere?

What is normal? Thanks.
Class C
  • BFL13's avatar
    BFL13
    Explorer II
    Nov 02, 2017
    pianotuna wrote:
    Otherwise known as a spit valve.

    DrewE wrote:
    There's usually also a little fill level vent valve thingy that is cracked open to determine when the propane is filled up to the maximum 80% level--one watches to see when liquid rather than gas spits out while filling the tank.


    Ok I have all that with this tank, so I am gradually getting the picture of what I have here. I found an old hand-out tucked away, that is "Handy Tips" from Manchester, dated 1985 that explains all about the tank etc. I have the usual Marshall regulator stuff, so that is all good.

    So really all we have to sort out now on the LP side is the furnace cycling issue. I believe it is the old, probably original thermostat at fault as has been suggested, so that can be solved. The furnace works through its starting and stopping sequences properly, so all good there now. (After getting the bugs out of it--actual bugs like dead and half dead wasps :) )

    Thanks for all the help everyone!
  • j-d's avatar
    j-d
    Explorer II
    Nov 01, 2017
    Like many if not most, we run on the road with LP on and Fridge in LP mode. To fill the LPG tank, we have to turn its valve off. But the Fridge itself needs to be turned OFF also, since it'll attempt to re-light itself once the LPG runs out. Whether Flame or Spark, we don't want an ignition source at the Fridge. Same would be true of Furnace or Water Heater, but we don't travel with those on. Basically anything with a logic board for electronic ignition.

    But to fuel Gasoline, I only turn the Fridge OFF. Jayco extended the gasoline filler way to the back of the coach. If they had not, the filler would be right at the fridge. There's probably an engineering/safety standard that dictated putting some separation between the two.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Nov 01, 2017
    Otherwise known as a spit valve.

    DrewE wrote:
    There's usually also a little fill level vent valve thingy that is cracked open to determine when the propane is filled up to the maximum 80% level--one watches to see when liquid rather than gas spits out while filling the tank.
  • DrewE's avatar
    DrewE
    Explorer II
    Nov 01, 2017
    BFL13 wrote:
    OK back from the first camping episode of four nights away off grid.

    We do not have that witness type double gauge. Sounds like a good idea though.

    Everything worked except the silly furnace would leave the fan running forever if all you did was turn the heat way down. Only way to turn off the fan is turn the little lever on the thermostat to OFF. Then the fan quits after its proper delay.

    So that means getting the place nice and warm before bedtime and turning it off. Back on in the morning. Not going to work if it gets really cold out, but ok for now.

    ...

    The big tank has the level gauge on the left, then the open/ close tap, then a round thing covered with white plastic, then the Marshall regulator (also with a white plastic cover)

    The round thing when un-covered is a grey shut- off valve looking thing, with the needle pointing along with the line, towards the open/close tap. Is this the auto shut off ??? The needle is raised a bit so it looks like you could turn it with your thumb to against the line flow, but why do that when there is the open /close tap right there beside it? So I am thinking this might be the safety auto shut off mentioned earlier in this thread ?

    Thanks.


    The furnace fan should shut off with the thermostat off. If I had to guess, I would suspect the thermostat of not operating properly, but it may be something in the furnace control board. Either way, it's something that ought to be fixed if you plan on doing much of any cool weather camping. (Do also check that the thermostat has the fan set to auto rather than on, assuming it has a separate fan control. Usually that control only affects the air conditioner, but perhaps on yours it also applies to the furnace.)

    The unknown thing with the plastic cover may possibly be the tank fill port? It might be easier to say with a picture, or maybe just watch when the tank is being filled sometime. There's usually also a little fill level vent valve thingy that is cracked open to determine when the propane is filled up to the maximum 80% level--one watches to see when liquid rather than gas spits out while filling the tank.
  • Photomike's avatar
    Photomike
    Explorer III
    Nov 01, 2017
    BFL13 wrote:
    On return home, having used some LP, and not having any battery charging (no alternator input with this rig) the batteries were at about 50% at 12.2, and the idiot light LP level monitor said three lights instead of four when we left, so that seemed to work. The gauge on the tank was also a bit lower than before.

    Plugged in shore power at the house and now with 13.6 volts, the idiot light LP level went back to four lights--Full tank! Oh well. the outside gauge still works right.


    The changing in levels is normal with the standard gauges in a RV. They only get you close, not exact. With propane it could be that it was on the line between the two lights and when it warmed up it moved up. Same will happen with water & waste tanks and the angle you are parked.

    Use them as a rough guide.
  • BFL13's avatar
    BFL13
    Explorer II
    Nov 01, 2017
    OK back from the first camping episode of four nights away off grid.

    We do not have that witness type double gauge. Sounds like a good idea though.

    Everything worked except the silly furnace would leave the fan running forever if all you did was turn the heat way down. Only way to turn off the fan is turn the little lever on the thermostat to OFF. Then the fan quits after its proper delay.

    So that means getting the place nice and warm before bedtime and turning it off. Back on in the morning. Not going to work if it gets really cold out, but ok for now.

    On return home, having used some LP, and not having any battery charging (no alternator input with this rig) the batteries were at about 50% at 12.2, and the idiot light LP level monitor said three lights instead of four when we left, so that seemed to work. The gauge on the tank was also a bit lower than before.

    Plugged in shore power at the house and now with 13.6 volts, the idiot light LP level went back to four lights--Full tank! Oh well. the outside gauge still works right.

    The big tank has the level gauge on the left, then the open/ close tap, then a round thing covered with white plastic, then the Marshall regulator (also with a white plastic cover)

    The round thing when un-covered is a grey shut- off valve looking thing, with the needle pointing along with the line, towards the open/close tap. Is this the auto shut off ??? The needle is raised a bit so it looks like you could turn it with your thumb to against the line flow, but why do that when there is the open /close tap right there beside it? So I am thinking this might be the safety auto shut off mentioned earlier in this thread ?

    Thanks.
  • maillemaker's avatar
    maillemaker
    Explorer
    Oct 30, 2017
    I'm surprised that when you turn your gas off that your lines empty so much that they need extensive purging when you turn them back on.

    My old 1990 Winnebago Warrior has a pressure gauge built into the system. I access it by taking off the access cover on the outside of the RV for the refrigerator. It has two needles. One measures the pressure in the propane line, and the other is a manual "witness" indicator. You turn on the propane, then manually dial the witness indicator to match the pressure indicator, then turn off the propane. Check on it in a couple of hours. The two needles should still be lined up together. If the pressure has dropped, it will no longer match the witness indicator. This means that you have a leak in your system and it is not holding pressure.

    I turn off my propane at the tank every time I am done using the RV and put it back in storage. If it has been a while since it was last used, sometimes, but rarely, I have to turn on a burner on the stove and let it run for a few seconds before it will light with a lighter. It is at the end of the run for my RV so if the stove runs everything else should have gas also. Most of the time though everything lights up without effort because my system does not leak.

    Steve
  • pnichols's avatar
    pnichols
    Explorer II
    Oct 26, 2017
    O-B,

    Thanks for the clarification!

    That's great info, which means that when I turn OFF the 12 volt coach solenoid switch to gas up .... I'm completely safe from there being any open flames in the RV.

    After gassing up it's VERY IMPORTANT to remember to turn the coach 12 volt power switch back ON so that the refrigerator comes back on line. To make sure, I installed a voltmeter on the cab dash to monitor the coach's 12 volt system so as to know when it's powered up and at the proper voltage.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 25, 2017
    pnichols wrote:
    Our RV has only one pilot light - the oven. We never leave that pilot light lit after each use of the oven, so there is never an open flame there when we're gassing up or traveling.

    The water heater, and refrigerator all use electronic ignition to light up their flames, so they won't light up with no 12 volts present while we're gassing up. We never leave the water heater ON unless we need it within a few minutes or have just used it, so it's burner would never present an open flame while we're gassing up.

    However, now I'm wondering: If the refrigerator's flame just happens be burning during an ON cycle when we pull into a gas station ... will it remain burning to complete the cycle even after I turn OFF the 12 volt switch before gassing up?

    NO!!

    Fridge, water heater, furnace etc that have gas valves with solenoids NEED the 12V DC to hold them open.
    Loss of DC they go closed immediately.

    Loss of DC the circuit boards can not function

    Loss of DC......no propane appliances except those that are MANUAL operation

    If the answer is yes, that could be an issue because the refrigerator's lower airflow intake vent is close to the motorhome's gasoline filling port. I'll have to make a test to see if the refrigerator has a 12 volt powered solenoid that turns OFF it's propane flow it if there isn't any 12 volts available in the coach. I sure hope that Winnebago set it up that way ... as just conveniently turning OFF the coach's 12 volt switch would then make open propane flames a non-issue, other than us manually lighting a cooktop burner while gassing up (not likely).


    Correct^^^^^^
  • pnichols's avatar
    pnichols
    Explorer II
    Oct 25, 2017
    Our RV has only one pilot light - the oven. We never leave that pilot light lit after each use of the oven, so there is never an open flame there when we're gassing up or traveling.

    The water heater, and refrigerator all use electronic ignition to light up their flames, so they won't light up with no 12 volts present while we're gassing up. We never leave the water heater ON unless we need it within a few minutes or have just used it, so it's burner would never present an open flame while we're gassing up.

    However, now I'm wondering: If the refrigerator's flame just happens be burning during an ON cycle when we pull into a gas station ... will it remain burning to complete the cycle even after I turn OFF the 12 volt switch before gassing up?

    If the answer is yes, that could be an issue because the refrigerator's lower airflow intake vent is close to the motorhome's gasoline filling port. I'll have to make a test to see if the refrigerator has a 12 volt powered solenoid that turns OFF it's propane flow it if there isn't any 12 volts available in the coach. I sure hope that Winnebago set it up that way ... as just conveniently turning OFF the coach's 12 volt switch would then make open propane flames a non-issue, other than us manually lighting a cooktop burner while gassing up (not likely).

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