Red/Green Propane Indicator Problem

I got a new Camco regulator double tank thing and a supply hose. Tried just the new supply hose on the old Marshall. Now it all works.

So it was the one bad supply hose all along. Not sure how that fits with my earlier discoveries, but it works.

Now I have an extra double tank thing with indicator. The Camco new indicator is just a tiny window thing in the front switchover lever. It can't be seen from the side, so I put that in the 5er instead of the old Marshall. The Marshall is now in the 1981 camper. The Marshall top-mounted red/green can be seen from the side the way it has to be visible in the camper.

So now the camper has an indicator instead of just the old double tank T with no indicator, the 5er is back in business, and the RV store made some money! Another wasted day in the RV salt mines :(

I had it going on one side only but it didn't last. I was swapping hoses around and with one hose off the red/green so there was just the hole there, and with the lever pointing to that hole, I had the hose on the other side on and onto a closed tank.

I slowly opened the tank and there was a good hiss from the other side hole while it stayed red. Then I turned the lever over to the tank side and it turned green. Hooray. I tried it opposite sides and no joy. I did it a few more times and then it wouldn't do it any more even on the "good" side.

Also I could only get it to work with one of the hoses but it didn't matter which tank. So it seems the Marshall thing is toast and maybe one supply hose.

I swapped everything around I could think of to isolate the problem and get repeatable results and that's where I got to. So now it must be time to throw money at it! :) Oh well.

Thanks for the advice and tips everybody. I did notice a difference when opening slowly (before the Marshall died totally) so that does work for sure.

Let the tanks sit for 30 minutes to an hour or more. Then attach the hoses and very slowly, in tiny steps, open the valve.

Not there yet, but I tried an RV tank on the home BBQ and it worked. then I took the regulator/pigtail off the home BBQ, took out the Marshall (two pigtails removed one each side of the red/green up top and the trailer line below.

Attached the BBQ thing to the trailer line (just the start thread --they are different threads, but it was on just good enough) and it all worked, getting good flame at the RV stove.

Next I poured mineral spirits down the three holes in the Marshall and sloshed around, got out some orange fluid and put the Marshall back together and hooked up. Slowly opened the tanks supply side first, and the indicator is still showing full red.

I did not substitute the Rv tank- to- Marshall pigtails to the BBQ to see if they were clear/open so that is unproven. I have a regulator I could use for that. With the pigtails on the tank but off the Marshall, and tank open, could not smell propane, but felt a very slight cold air on hand. No hissing.

I did not try the BBQ pigtail on the Marshall as the supply side either. So two things yet to try before it is narrowed down to the Marshall itself.

The OPD valves will not pass LP unless a hose is hooked up- you can open the valve, and nothing will come out. The pigtails have collars that melt at a low temperature, which allow the pigtail end to pull out, shutting the flow in case of fire. The other check valves are in the pigtail- they are excess flow valves, which will shut the flow in case of a line break- they will also shut off if the valve is opened to quickly. To reset these, the valves must be shut, hoses disconnected to equalize all pressures.

2oldman wrote:
Remove any hoses from a tank, open slowly, see if propane comes out. IF so, deduction is bad regulator ( I guess)

Can't do that with OPD valves.

Remove any hoses from a tank, open slowly, see if propane comes out. IF so, deduction is bad regulator ( I guess)

No luck with the slowly trick.

If it is the tank valves that are stuck shut even though opened, how can a new regulator help? Or are there some other valves closer in either side of the red/green thing?

Seems funny that it is the same problem on both sides. Two tank valves going funny at the same time? I did try a third full tank off the BBQ and that didn't make it go green either.

If doing what DownTheAvenue suggests doesn't work, then I would just replace the regulator...I'm on my 3rd one, for whatever reason they go bad like anything else.

Yes, slowly.