Propane Flow

[DNOSSAMAN]

My system has to be purged of air in all propane lines after short periods of time in shortage. The unit will not go automatic to propane on stove or ref. without opening all heat units and purging air. I have read the books and am still having same results. Please help. 89 Newell Motor Coach.

Debbie Nossaman
Oklahoma City:confused:

[encantotom]

hi Debbie,

welcome to the gang.

i did some searching online and didnt come up with much. i will say that you need to be careful in working with the propane....nuff said on that.

clearly some air is entering the system somewhere. that is most strange.

how full is your tank? after you purge your lines will the stove run for as long as you want? how exactly are you purging the air out? just by leaving the burners on on the cooktop? what did you mean by running the heat.

are you sure the solenoid on the tank is open? it is the one controlled by the lp leak detector that is probably under your couch.

i am wondering if the solenoid is on, if the regulator could be an issue.

i am just speculating.

i would break it down to chunks. i would start turning off the propane valve to the individual appliances that use it and try it each time to see if it does the same thing. that is once you are sure the solenoid on the tank is staying open all the time.

start eliminating the pieces one at a time to see where the air is being induced if that is really the issue.

i am sure others will have some help to offer as well.

when did you get your coach and how long has it done this?

later

tom

[fulltiming]

There are several potential causes for this problem and most of them could involve safety issues.

Propane is under considerable pressure in the tank. The tank pressure can be 100-175 psi (pounds per square inch) as pressure is temperature dependent . The gas goes through a shutoff valve into a pressure regulator that drops the pressure down to about 10 psi then a second stage that further reduces the pressure (appliances are typically adjusted to use about 1/2 psi).

If air is getting into the propane lines you have a problem. My first suspicion would be a stuck pressure regulator which is closing down all pressure when the flow of propane ceases. That would allow air to seep back into the lines IF you have a defective/leaking valve or a small leak in a fitting or propane line. The leak to allow air back into the lines is the more potentially dangerous of the two issues. If you are not familiar with propane systems, I would have a propane specialist look at the coach and determine the cause. A propane leak can be deadly!!

[HoosierDaddy]

Yep, sounds like a regulator problem coupled with a leak. The leak could be relatively simple to find but the regulator (which could be 19 years old) should be replaced IMHO.
THIS IS A POTENTIALLY SERIOUS PROBLEM !