What Is "Water Column" In Reference To LP Propane Regulators?
Updated 08/11/2026 | Published 08/06/2026
Question:
What is a water column in reference a LP propane regulator?
asked by: Chris
Expert Reply:
Hey Chris, thanks for reaching out. A water column (WC) is a unit of gas pressure used for low-pressure propane systems. It represents the amount of pressure needed to raise a column of water by a certain height. Since propane appliances operate at very low pressures, inches of water column (in. WC) are much more useful than PSI.
For RVs, grills, and most propane appliances, the standard regulator output is 11 inches of water column. That works out to only about 0.4 PSI for comparison.
If you're replacing an RV propane regulator, 11" WC is the number you want to match unless the appliance manufacturer specifies something different.
Kevin K.
8/11/2026
Chris: About the propane regulator I purchased thru trailer.com: I used it successfully for about 5 years, similar to the OEM model that came in my 2017 Forest River RV, then my new one failed with a leak, I suspect a failed rubber diaphragm. Maybe 5 years is the life of these things? The replacement which I sourced from etrailer. Com also failed, in a similar way (I didn't perform an autopsy), after about 5 years. Sadly, that version that I needed to buy "on the road" cost $540, valve & installation, at an RV repair shop in Oregon, since I didn't have quite enough tools along. And couldn't buy mail order. I'm facing a similar issue with a dying water pump, for which I'll probably buy a replacement from etrailer.com. I trust them.