Moen shower valve install problems

Hi friends, I'm looking for some advice on installing a Moen shower valve (model #82355). This valve has threaded female inlets for the hot/cold lines and the same for the tub/shower outlets. I am using brass/cpvc male thread adaptors.

Here's the problem: I installed the valve using teflon tape at all connectors and ran a pressure test. After a few minutes a bead of water appeared on the exposed threads of the hot inlet. Everywhere else was bone dry. So, I disconnected the hot, removed the tape, and used teflon joint thread compound (oatey). No go - more water this time. Ok, it must be the fitting. I get another fitting and try it with tape. Same leak. Try it with joint compound. Same leak.

Ok, it must be the valve. So, I call Moen and to their great credit I had another valve in my hands the next day. Install with new fitting (+tape). Guess what? Another leak. Same place - hot inlet. All the other fittings hold perfectly well on both valves, so I sincerely doubt it is my technique. Plus, I've now tried three different fittings, so I doubt that is the problem.

I called Moen back this morning and the only advice I got so far was to buy my fittings from a different store. Ummm... but the cold side doesn't leak. A product specialist is going to call back this afternoon. I can't see what they can do besides send another valve or refund my purchase price. We like the trim on this one, though (it is a matching set with the sink faucet), so I'd rather not go shopping for a new brand. The funny thing is that I specifically chose Moen for its reputation for quality.

If anyone has a suggestion on how I can make this valve work I'd love to hear it. Or perhaps there is a high quality universal valve out there?

Thanks

Bill

are you using teflon tape and pipe dope together. If not try both not just one or the other

I didn't know that was a possibility. I'll give it a try.

bill

ya most of us plumbers always both use on any joints

Yep... Wrap on the teflon tape then goop on some teflon paste and screw it in tight.... Kinda like having a belt and suspenders!

So far so good - thanks for the response guys.

Bill

tape and dope.

Mkae that SOME of us plumbers, not MOST, because I think it is a very seldom used process, especially for everyday joints. And with it happening to so many different items, the only thing common to every try is the operator, so it could just be operator error.

Hj it must depend on where we work because i have never ever seen someone not use both unless it was a gas line, medical gases, ect....




hope it worked out for you scout

joints

I have NEVER used both and have not seen anyone in this area who does either.

hmmm weird

I'm like hj, I normally use one or the other.
I seem to use Teflon pipe dope the most.
Leaks? you gotta be kidding me. Doesn't happen.

There are other threads that incidentally discuss the pros and cons of tape, dope, both, neither, brands, etc. Here's one: https://terrylove.com/forums/showthread.php?t=20240. This might make a good sticky thread topic -- threaded connections.

threads

Why? Reading a few discussions about the pros and cons is not going to make any one change his mind about the way he/she has been doing it since year one.

Either method, pipe dope or teflon tape, should suffice on its own. The recommended wraps of teflon are based on a properly cut joint. Today's materials can often have lousy threads, which challenges the ability of tape to seal unless you use more, but there is a limit on how much you can use. If using dope, you need a sufficient quantity as well.

Using both doesn't hurt and might give a DIY'er a little more leeway in getting a joint that doesn't leak. It takes a little skill to determine when enough is enough on sealer and how tight the joint needs to be.

When I was first learning the trade i was told the tape does the sealing and the dope was there to provide lubrication while tightening, and the extra leak protection was just an added bonus.

In my (limited) experience, teflon is plenty slippery by itself...no need for pipe dope for lubrication purposes.