Sunday, September 19, 2021
Sunday, September 19, 2021

City water inlet regurgitates — help!

By Chris Dougherty
Chris Dougherty is a certified RV technician. Here is a letter he received from a reader while he was serving as’s technical editor.

Dear Chris,
I have an issue with the fresh water from my fresh water holding tank shooting out the city water inlet connection when I turn on my freshwater tank pump. There is a trickle of water coming to the faucets. However, when the city water connection is hooked to external water source, everything seems to be OK. Do you know what might be causing this, and can it be corrected fairly easily? Thanks. —Jessie Lynn

Dear Jessie Lynn,
You’re in luck … sort of. This is a somewhat common problem, and a straightforward fix. Inside the city water connection is a small plastic, spring-loaded valve called a backflow preventer. The valve shaft itself is plastic and wears, releasing the spring, and occasionally a second small part that some manufacturers use to hold the spring in place. Basically, this is a non-serviceable part. I’ve tried a bunch of times, and whenever I have tried to glue the thing together, it doesn’t work long enough to make it worthwhile.

There are two things you can do. First, and best, is to replace the city water inlet. They’re available from any RV service facility or store. In most cases it’s three screws to pull it out and (hopefully there’s enough slack in the pipe) unscrew it from the plumbing system and replace. Make sure to use plenty of sealer on it if it’s on the outside of the coach. There are different styles and brands, so I would match up what you have and follow the manufacturer’s instructions if needed.

A second, temporary fix is to get a hose shut-off from a home center and screw it into the city water inlet. You’ll have this thing sticking out from the side of the coach, but it will work. The pieces of the valve will be floating around inside the valve head, so some flow restriction can be expected.

##RVT778 ##RVDT1286


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1 year ago

Our city water inlet has a nylon male threaded plug that I screw in to keep out debris. It also would solve this problem.

Two Buck Chuck
1 year ago

One thing we’ve found in our three and a half years on the road is that. if you frequent areas with hard water the inlet will wear out fast. We are on our third in as many years. Each of the ones I removed were caked in hard water deposits.

1 year ago
4 years ago

I’ve had this problem too. I was educated on this spring valve and simply use your finger to push it in and release, to reset the seal and spring. Rather than replace it, try it first. Another issue I found is that some use a direct hose hanging from the valve. Try a 90 degree extension, so the hose doesn’t “hang” from the city water valve (more direct from ground up). This way the hose end will not flex the spring and valve thus making it leak. I also use a 90 degree with a shutoff on city water, and the compartment closes fine. I tried plastic and doesn’t work as good as brass fitting. Thanks for allowing shared frustrations. One more hint. ALways turn water supply off at the hose bib when you leave your campsite temporarily. Hoses and fittings can and will leak and the consequences can vary.

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