Propane tank heat buildup issue

[Jogorman41]

Hey all, I have a 2012 Greyhawk 31DS and am having an issue with the propane tank getting hot and popping the safety valve at the bottom of the tank. I replaced the valve recently, and after a 3 hour trip this past weekend, the new valve was “seeping”. I removed the pressure from the overflow valve and safety relief valve reseated. At the recommendation of my local RV service center I took it to a propane service center. They tested everything ad it all seemed to be within spec - new valve confirmed to be correct one, and having the right amount of pressure required to make it open. What I’ve noticed is there seems to be a lot of heat buildup around the tank - I can only assume from the exhaust. There is a steel shield in place on the frame between the and exhaust and propane tank, the exhaust isn’t compromised that I can see. The tank gets too hot to touch - has anyone had a similar problem and how was it solved? I’m looking at wrapping the exhaust, using spray insulating foam around the top and back side of the tank, and perhaps installing a vent in the door to allow heat to dissipate. The tank went from ~100 PSI cold to 225 PSI sitting in the sun with the engine idling in a bout an hour. Valve is rated at over 300PSI before it will release .

[Grumpy]

Originally Posted by Jogorman41

Hey all, I have a 2012 Greyhawk 31DS and am having an issue with the propane tank getting hot and popping the safety valve at the bottom of the tank.

Did it just start? Seems weird if so, since the rig is 8 years old.

[Jogorman41]

Just started this season (I purchased the unit May 2019 drove it for about 6500 miles without any issue being observed. ) Has done it on every trip this year. I figured a new valve would be the answer - was disappointed when the new valve did the same thing.

[Nature Ist]

I would be looking at excessive heat coming from your exhaust system first. I assume you are running a gas engine, and could have a catalytic converter or other exhaust issue causing excessive heat; it could also be an engine issue with exhaust gas temperatures above limits. If this is the case, you need to get it to a good mechanic to evaluate, and possibly prevent huge problems. I would act immediately to be sure you don't have an imminent safety issue.

[Jogorman41]

Thanks for the input - I’m looking at the exhaust as the cause of the buildup - nothing else makes sense. I think the propane tank is the canary in a coalmine. The RV is running well within range on temp gauge - good idea on the cat - I hadn’t considered that but that could be a cause. It’s interesting because the power feels down compared to my last 2 RVs with the same chassis, I assumed it was just the weight - The coach only has 19k miles but a clogged cat could certainly cause heat buildup and power loss issues. All the heat shields look to be in place and there are no obvious holes or cracks in the pipes anywhere. I recently did a trip through VA and WV and there were some of the inclines I could barely maintain 45MPH with a 16 ft aluminum trailer and Honda Civic onboard. The relief valve blew the first time about 30 minutes beyond the Chesapeake tunnel with just under 1/4 tank, and did it every 30 minutes until the tank was empty. Scheduling appointment to have the exhaust looked next, before my next adventure!

[Jogorman41]

Issue was confirmed as a failed catalytic converter as diagnosed by @nature 1st. Truck had 2 faulty coil packs - which apparently led to the early cat failure according to the tech that diagnosed it. He suspected the issue was caused because the RV sat for a long time unused. Previous owner put 10k miles on it in 7 years, I have put 9k on it in 14 months - so it is getting some use for sure now! Thanks to all who provided input.

[Jagiven]

Glad you got the issue resolved!

FYI, if you are still thinking about some insulation for the propane tank, do not use spray foam. You will have heaps of trouble. First; most is not made for that type of heat and could create a new fire hazard, second; most absorb water (rust creator), third, makes inspection and replacement of the tank nearly impossible. If you did want to add some insulation, I would consider something like Dynamat on the heat shield with some foil HVAC tape wrapped over the edges. Now that you have your CAT fixed, it really should not be an issue.

[Jogorman41]

Thanks for the tip. I was a little hesitant to add foam as Jayco didn’t- assume for some good reason! There is actually a piece of heat shielding missing, I’m going to add a piece of aluminum Along the frame between the new cat and the propane tank. Probably not necessary but an easy modification to protect the tank. I hadn’t really thought of a failed cat on a 19k mile vehicle!

[Jagiven]

Originally Posted by Jogorman41

I hadn’t really thought of a failed cat on a 19k mile vehicle!

I get more concerned on low mileage vehicles than high mileage. Don't be surprised if a few more mechanical items come up. Things like belts need to rotate to stay flexible.

[Jogorman41]

Yeah for sure. I had a bunch of coach maintenance that was required. There was a June bug nest in the back of the water heater.