help! unable to fill propane tank in rv

I think some do not understand how a MERCEDES Sprinter Class B LP tank is mounted and filled. Because of the Chassis design, they install the LP tank underneath amidships or in the rear amidship. They then install a 12 volt cut off valve,THAT ONLY AFFECTS FLOW OF LP TO THE RV. This does NOT affect filling. They then run a hi pressure fill hose and a hi pressure 80% from the tank to a "box" mounted under a outer sidewall. This box will have the ON/OFF switch to flow LP to the RV and will have the 80% valve and a remote fill nozzle to connect the LP filler nozzle to. ALL you do is connect the LP station fill nozzle/ OPEN the 80% knob and then fill. NO other valves electric or manual is used on the fill tank side. As I stated, IF they open the fill nozzle too fast the liquid LP will freeze the auto shut off spring AT the tank valve. So, you just remove the fill nozzle and SLOWLY open to prevent freezing and after 10 to 15 seconds you open the nozzle fully. Doug

I may not understand the issue. I have a 92 Eagle and they had trouble filling my tank. No one knew how anymore. There was a button underneath they had to push before the tank would take propane, otherwise it wouldn't flow. The older guys were familiar with it, it was on old rigs, but it got to be a real issue finding someone that could do it. So couple years ago in Orlando I found a private shop that would empty my tank, put on a new valve that is like what everyone uses now. A plus was they had to recertify the tank, we were concerned they might have to replace it, but the shop guy said that was very rare. They recertified, I now have a valve that anyplace can fill and all is well. I was also happy to know my tank was safe too. They said anytime they do something like that they have to pressure test the tank to make sure its ok.
Just throwing this in, in case it might pertain to you.

If I read this post correctly, both RVs have built in tanks, not portable.
Since it had a full tank you do not have to purge it. You only purge new tanks.
You do not need to open the "Visual Overfill indicator Valve" when you first start filling a empty tank. Yes you do before it get's 80% so once it starts spitting liquid you know it's at 80%.
I think Chevyman2 (above post) has your solution.

Well it may not be the Sprinter at all.
As a propane dispenser I have learned that if the shut off valves on the big tank are opened too fast, the line will get a "vapor lock" type situation, and will not allow any flow of propane.
Since you left and returned, the Uhaul guy likely shut the valve off, then re-opened it the proper way, which allowed the pump to work as designed


BTW-the same is true for the "empty" tank as well. If opened to fast, it will not accept propane

Does this is tank have a 'solenoid valve' in addition to the manual shut off valve?

Solenoid valve needs 12 V DC to open.........LP Detector/Alarm tripped closes solenoid valve OR lack of 12 DC power will trip it closed also

Did you open the bleed valve to let air out? It want fill unless you do.

I would take it to a propane dealer and have them check it out!

Trevor, Greetings,
All types of travel units are RVs, not just MHs. That cliarified, I'd like to help with your filling issue.
MHs mounted tanks are equipped with an 80% full 'spitter' well described by a previous poster. opd equipped portable bottles 40# propane capacity and under are equipped with 80% liquid overflow valves, as well as check valves in the fill point that can sometimes be a challenge to overcome when connecting the fill hose. Sometimes it takes a strong grip to tighten them enough to overcome the check valve.
The other reason is that if your bottle is a portable, designed to be used in say, horizontal, but filled vertical, that the fill technician did not see that direction on it.
This is common on TC & forklift bottles, not well labeled.
Sincerely, Max

Personally I'd take it to a propane dealer, assuming you have one. Uhaul isn't known for having the best and brightest employees. At least in my area. A propane dealer will know the tank and what it takes.

donn0128 wrote:
Tank ever been purged?

This new RV came with a full tank of propane that had already been filled. Now that it was nearly empty I wanted to refill it, but propane would not flow in. I have never purged it, but then again, I have another RV with the same tank and I have never had to do anything special other than refil it at the local uhaul. It is a 6.7 gallon tank. Am I missing something or do you think a pro needs to take a look at this?