Dear Dave,
After using the propane, I turn it off at the bottle valve. When I get to my next stop, I turn it back on. The lines are no longer pressurized and it takes a while for the propane to reach the stove and light. If there are no leaks in the system, shouldn’t it come in immediately? Does this mean that I have a propane leak somewhere? Thanks. —Matt, 2019 Rockwood Mini Lite 2205S
Dear Matt,
The only reliable way to verify a propane leak is to have a certified technician perform a water column pressure test on the LP system. This can be done at a supply line, such as the refrigerator if you have an absorption model that operates on LP.
Another method is installing a pressure gauge (manometer) somewhere in the gas line on the coach.
Years ago, Winnebago Industries installed a manometer in the refrigerator supply line. It used a dial gauge that would show a pressure drop if there was a leak in the system.
GasStop valve
Another option is installing a GasStop® valve at the propane tank. This device not only provides added protection by automatically shutting off flow if a leak is detected, but it can also indicate a pressure loss while the coach is in storage. You can get one on Amazon here.
However, before assuming you have a leak, consider a very common issue involving how the DOT cylinders are turned on.
Excess flow valve
Your LP system includes an excess flow valve inside the cylinder connection. This valve contains a spring-loaded needle and seat designed to shut off propane flow if it senses a sudden surge—something that would normally indicate a major leak.
If you open the cylinder valve too quickly, it creates a rapid rush of propane and pressure. The excess flow valve can interpret this as a leak and immediately restrict or shut down flow.
When this happens, it can take several minutes for pressure to equalize and for the spring to reset. The reset time varies depending on the size of the coach, the number of LP appliances, and the length of the supply lines.
Before scheduling a leak test, try this:
Turn the cylinder valve on very slowly to prevent a sudden surge in pressure. If the problem persists after doing this, then have the LP system professionally tested.
You might also enjoy these posts from Dave
- Twelve days of Christmas RV tools – Ninth day: hand-held LP leak detector
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- The ultimate guide to liquid propane (LP) systems
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Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Generally speaking, when I shut off my propane tank valve for a few hours (without bouncing down the road), there is still propane at the furthest point in my system. However, when I do so for longer times (a couple weeks or more), I generally have to evacuate air before the appliances have propane. I have a Gas Stop device. I evacuate the air at my stove with a lighted butane match. When the burner lights, other appliances will successfully auto-ignite.
Bottom line, yes I think there is leakage at one or more appliance valves or joints or hoses, but not enough to show up in a test and not enough to be worrisome.