View Full Version : Installing pressure reducing valve DIY?

05-08-2006, 06:46 PM
Got a simple question (or so I wish?), is it easy to change the pressure reducing valve by myself? The plumper is asking for 275 while I found out the PRV at lowes for only 40 bucks. If it's easy, any special care I need to take? Any info is greatly appreciated!!

A little background: my water pressure is about 140 - 150, and the TP valve is constantly leaking.

Thanks everyone.

Bob NH
05-08-2006, 07:16 PM
First, is that the delivered pressure, or do you have a PRV already and no expansion tank. That is a very high pressure for the utility to be delivering to you. What is your pressure immediately after you run some water?

If the utility is delivering 140 psi water then they have a problem. Either that or you live in the low area of a very hilly city.

If the pressure is down after you run the water, and then comes back up in 5 minutes or so, you probably have a bad PRV. If it comes up only after you have used hot water and it takes 30 minutes or more, then you probably need an expansion tank, or your expansion tank has failed or is full of water because it has no air.

Several people have said they have a problem with pressure loss with some PRVs. You want to make sure that what you get is big enough. Are you planning to get the same model that has been giving you good service until now?

To change the PRV you will need to get the water supply shut off. If the PRV is after a valve that you can shutoff, then it should be easy enough. Try to find one that has the same end fittings.

If it is not after your shutoff valve, then you will need to get the utility to shut it off.

05-08-2006, 07:35 PM
Thanks, Bob. The pressure is after the PRV (I tested it on the faucet outside the wall), so I believe it's "delivered" pressure (I don't quite know what the definition is). After we run the water, it drops down to about 60s. And as soon we turn it off, it comes back slowly back to 140 or so. So it sounds like a bad PRV as you said. We did have an extension tank installed in Nov last year after we saw leaking. So I assume the extension tank should be good.

Not sure what our model is, I only wrote down the PSI specs and went to lowes to find out they do have one with similar looking. Is that not enough and I should get the same model?

We have shutoff valve on both sides of the PRV, so I think there will be no problem for us to shut them off.

So here goes my question (again): is the PRV from lowes (they only carry one of the same size that we have) good enough, or should I try to find one that we have now? Other than two big wrench, anything else I should be expecting to have before doing it? Also, there is a big (about 1/4 inch) metal wire that bypasses side by side with the current PRV, what's that for? Will there be any problem removing it and puting it back on after we change PRV? (I think it's for grounding, but I am not sure)

BTW, we are in Atlanta, GA.

Thanks again. I will try to take some pictures and post here when/if I do it.

05-08-2006, 07:42 PM
The wire is likely a ground...shouldn't be a problem removing it momentarily. If you have a multimeter, you could carefully remove one end and then check to see if you ahve any voltage across the thing to the place you removed it from. The plumbing system is not the best ground for a house in today's codes if I understand things properly - more common on older homes.

05-08-2006, 07:55 PM
Thanks, Jim. Interestingly enough, the house is 6 year old and you'd classify it "old", :D.


05-08-2006, 11:06 PM
Most copper piping is grounded, even if the panel has two grounding rods.

The wire is to continue the grounding across the prv.
The reason metal pipes are grounded, is if a hot wire comes in contact with them.

Better for the ground to take the charge than you or a loved one.

I think the plumber quoted a reasonable price.
You would be asking him to come to your place, on his time, with his tools.

I think most plumbers would agree, that it's rare that a new prv can just be poped in.

The only way to find out, is to try it.
If the pipe needs to be longer or shorter, you can always cut it and solder on a new fitting or two.

05-09-2006, 07:04 AM
Thanks, Terry, for the info. I tend to try installing myself now, but I will keep your advice in mind. Very much appreciated it.

05-09-2006, 12:50 PM
Other than two big wrench, anything else I should be expecting to have before doing it?

Two wrenches will be sufficient assuming you have union connections on both sides of the PRV, and assuming that the replacement PRV is exactly the same size and length as the one you are replacing. If not, you may have to do some soldering.

05-09-2006, 07:47 PM
Thanks, jk60. We were able to get the work done tonight. The PRV is the same one (both from Watts). Other than it leaked in the beginning and we had to unscrew one and put teflon tape again, everything went very well. The outlet water pressure now stays around 68. What a relief.

Only thing now is that it seems to be still leaking, not dropping, but you can see the water around the bottom connection. My father-in-law says the tape should expand and settle in some time after which we should not see any water again. I sure do hope so, otherwise, we may have to unscrew it and put more teflon tape on.

Do anyone has any suggestion to this issue?

Want to thank you guys again for your input, this is my first major plumbing project and it went fairly smooth.

Enjoy life! :)

05-09-2006, 07:57 PM
I've also had my share of problems lately with some threaded connections where I only used teflon tape. What has worked well for me in resolving this is to wrap teflon tape on the male end of a fitting and then work in some plumber's putty into the female threads. Screw them together and that should do the job. I've not had any leaks after this procedure.

Good luck,


05-09-2006, 08:16 PM
Plumbers putty will do nothing for threaded connections. Did you mean pipe dope?

05-10-2006, 07:59 AM
Cass - Perhaps I am using the wrong product in this application, but Oatey plumber's putty it is, not pipe dope. I've had leakage problems when I installed my own PRV, an expansion tank, and a few other threaded connections, but the combination of the putty and teflon tape resolved everything.

Gary Swart
05-10-2006, 10:27 AM
I have never been overly impressed with teflon tape. I used to use it, but it seemed to be such a hassle to get it on just right especially in tight, awkward spots. I finally went back to regular old plumber pipe dope and never looked back. Yeah, it's a tad messy, but just wipe around the end of the pipe with the brush, put the joint together, and wipe off the excess if it's in a place that appearance matters. Plumbers putty really isn't intended for threaded joints, I suppose if the threads are filled with it, it might work. I'll stay with the dope.

05-10-2006, 03:20 PM
If it worked I don't know how as it doesn't stick to threads.

For thoes of you who want the best pipe dope Gasoila is in my NSHO the best.

There are plenty of different dopes that work fine but I like Gasoila. It runs about $20.00 can.

05-10-2006, 07:24 PM
For thoes of you who want the best pipe dope Gasoila is in my NSHO the best.

Cass- Just for my own future reference what is the part number/description of the Gasoila pipe dope that you are recommending? There is soft set, hard set, 100, NT, etc, listed on their website.



05-10-2006, 07:29 PM
Gasoila soft set

05-11-2006, 10:50 AM
Guys, yesterday, my in-law unscrewed it and put more teflon tape on and screwed it back in. Everything is ok now, no leaking. We can finally close this project now.

Thanks so much for everyone.

05-12-2006, 05:13 AM
I would not remove it at any time if at all possible, unless you know for certain how the building's grounding system is configured, and whether this jumper is required, or if it's just there for show.

05-12-2006, 05:16 AM
I would not remove it at any time if at all possible, unless you know for certain how the building's grounding system is configured, and whether this jumper is required, or if it's just there for show.

I have never seen a ground wire installed for show.