Replacing Your Main Water Line Cutoff Valve

TLDR: Concise Instructions


It all started with a leaky tub faucet. “Crap!” I said probably too loudly near my 3 year old son, who had just gotten out of the bath. This was early last fall (2019) I believe.

Fortunately I had faced this problem before: I knew it was likely a broken faucet cartridge, which I had replaced before (after paying a plumber WAY too much to do this simple operation for me shortly after we bought the house and I had far less house-fixing skills). This video is one of many on YouTube that explains this relatively easy task.

So off I went to Lowe’s at 8pm while my wife was finishing the bedtime routine with our son (back in the pre-coronavirus days when Lowe’s was open late) to buy a replacement faucet cartridge. I was quite upset initially when they didn’t have the exact item they claimed was in the store, but fortunately that led me to looking even more carefully and finding a generic version that was even cheaper. Score!

Back home I go to turn off the water to the house before starting the operation. Guess what? The homeowner’s water cutoff valve didn’t work – water kept flowing no matter how I turned the valve. So what do you do when it’s 10pm and you can’t get the stupid valve to close? Well you get super frustrated and start twisting it even harder until it breaks! Duh! I was extra mad because this was the valve a plumber had replaced only a few years before.

So then I tried to close the city water meter valve. And guess what? That too would not close all the way. Water kept flowing. I was <sarcasm> beyond thrilled </sarcasm>.

So it’s 10:30pm and I’ve got a leaky tub faucet and no way to turn off the water to the house. I was about to give up for the night and just accept that we’d waste a bunch of water that night (fortunately the leak wasn’t gushing or anything). But before going to bed, I thought I would at least leave a voicemail with the county utility folks, so that hopefully I’d hear from them first thing in the morning.

But crazily enough someone picked up! After recovering from my initial shock I blurted out the situation. The guy said he’d let the repair folks know about the situation. I then said I actually have an active leak, and he then said “oh, well then I’ll call their on-call guy.” On-call guy? Wow, OK. Then 10 minutes later I get a call from this “on-call guy”, and he says he’s sending out a couple of his repair guys. At 11pm. Whoa, OK!

They arrive about 30 minutes later, and promptly confirm the valve won’t shut. Which was a big relief, because if that hadn’t been the case, they would have charged me some undisclosed fee. They then start to dig up all the ground around the piping, and toil at that for about an hour. I then come out to see how things are progressing, and they tell me they’ve managed to find yet another cutoff valve deep underground that was upstream of the broken meter valve, stopping water to both our house and our neighbor’s house. I was very relieved to hear they wouldn’t have to cut off water to the entire street, and that it was the middle of the night so it wouldn’t hopefully impact our neighbors.

Unfortunately they did not have the parts to fix the meter valve though! So off they went to their shop to get the needed parts – 30 minutes away! “But”, they said, “since the water is now off you can do your repair inside if you want”. So it’s a little after midnight and I found myself doing the faucet cartridge repair – which fortunately went well. When they got back an hour later, once again they found they did not have all the parts they needed! Whoa, these guys work insanely late I thought. I let them know I had done the repair inside the house, so they said they were going to put the original broken valve back in so we would have flowing water again and then return the next day to replace it.

So after getting just a few hours of sleep, I headed to work the next day and then returned home to find a totally new water meter, valve, and enclosing box! Wild.

BUT, I also discovered that the water flow was about 90% of what it had been before – just barely less, but noticeably so. I was pretty convinced it was unlikely to be the new valve they had installed, and it was mostly likely the broken homeowner’s water cutoff valve downstream. I guessed it was probably stuck about 90% open.


Fast forward about 6 months, and I still hadn’t done anything about it. I then finally got motivated because my wife and I were really annoyed about the lack of flow in the upstairs shower (the valve furthest from the water supply). So I started doing research.

I was sure I would find a bunch of YouTube videos on how to do the exact procedure I needed. That’s always the case these days, right? And while I found a couple “This Old House” videos that were kind of close, they weren’t really what I needed.

I also found this article relatively early in my search, but initially it did not seem to pertain to my situation either. But the more I studied my situation and this article, the more I realized that this was the ONLY online reference I could find that directly covered my situation (though I was fortunate to not have the complicating “bonding jumper” described in the article). I could not find a single YouTube video of how to replace a cut-off valve next to the water meter using the connecting nut and pipe attached to the water meter, as shown in this article.

Beyond the fact that I couldn’t find any YouTube videos for my exact setup and problem, I had a couple major factors that gave me pause when considering doing this project on my own:

  1. If I failed, we’d have no running water at all in the house until we could get a plumber to come out and fix my mistakes – not much margin of safety!
  2. I had a funky set up, with galvanized steel, PEX, and copper pipe around this broken valve – none of which I had much experience with!

But despite these significant obstacles (for me), I decided to power through and give it a go. I figured worst case I’d just have to call a plumber and we’d be without water for 12 to 24 hours – not the end of the world.

Initial Setup

Here’s the situation I faced, with the broken valve in the middle:

And see how the pipe goes under an opening into a black box? Here’s what the inside of that black box looks like:

Initially I wasn’t sure if the valve was a threaded connection (i.e. screw on/off with the pipes) on both sides of the valve, versus a soldered connection. I asked that question on a plumbing forum, and one person’s confident response was enough to convince me it was a female to female threaded valve, and thus I could use just a pipe wrench and normal wrench to unscrew the valve from the pipes (which turned out to be the case). Thus if you have set up like mine, and you see at least some threading on either side of the valve, you can likely assume you have a “screw-on” valve on both sides of the valve. 

I made some crude measurements of the pipes and decided it was likely the pipes were  3/4″.  I also could not initially tell if the blue pipe was PEX (good) or polybutylene (PB – bad!). Eventually I dug up the dirt from underneath the pipe, wiped it down, and managed to find some text on the very bottom: “PureFlow-ASTM F87…”.  Googling that did not reveal a definitive answer, but adding “PEX” to the search provided plenty of relevant results and adding “polybutylene” or “PB” did not – so I was convinced I was dealing with PEX, a huge relief (though in the end I had to replace it anyways, see below). 

First Idea: Just Unscrewing and Rescrewing

Based on the above instructions at, initially I was pretty excited that this might be a relatively simple project (though past limited experience also told me that plumbing projects are usually more challenging than expected). Hopefully I could just unscrew the coupling nut connecting the pipe to the meter, then unscrew the pipe from the valve, then replace the valve, and then screw everything back together in reverse order.

I really wanted it to be that easy. REALLY wanted it. Unfortunately, despite carefully measuring and matching the “face to face” length of the new valve versus the old valve, in the end it was obvious that the new valve was longer than the original valve – and thus the pipe would no longer fit between the valve and the meter. I tried like crazy to squeeze it in, but it was not going to happen.

So you can imagine my despair when it became obvious that it wasn’t going to be as easy as I hoped. If you can’t imagine it, here’s a detailed description of my brain when I realized the pipe was just barely too long with the new valve: “AARRRGGGG!!!!! Why is life so horribly and cruelly unfair!!!! This is truly the worst thing to happen in the history of humanity!”

Next Idea: Cut PEX and Press Fittings, Replace with new PEX and Crimp Fittings

So after I got over myself and calmed down a bit, I realized I would have to take out the current PEX piping and use a different length PEX pipe. Very fortunately I was prepared for this – I had purchased a 5’ long tube of PEX just in case (see my son wielding the PEX as a charging samurai warrior), along with the associated tools: a PEX cutter tool, crimp tool and crimp rings, and miscellaneous adapters for connecting to the threaded valve and copper pipe (see list of supplies).

So I took the plunge and used my PEX cutter tool to cut right through the middle of the short blue PEX pipe (which turned out to not be necessary, but of course I didn’t know that at the time). I then proceeded to try using a crimp cutting tool to remove the current press-seal PEX connectors from the adapters to the valve (a screw connection adapter) and the copper pipe (a soldered connection adapter). If you have any experience with PEX press-seal PEX connectors, you probably know what happened: I failed miserably. The press-seal PEX rings use a totally different tool to seal and thus require a totally different tool to remove than a standard crimp ring cutter.

Frustrating failure once again!!! Will nothing go right?!?!?

Next (FINAL) Idea: Replace PEX Adapters – Including SharkBite Connector

Then as I was sitting there stewing in my own self-pity, I had an epiphany – I should be removing these entire adapters and using the new ones I bought from Lowes! Duh Corwin! No idea why it took so long for me to recognize this simple fact, but I was hugely relieved when I did.

But if I cut the copper pipe just beyond the current soldered connection PEX adapter (using this pretty simple ring-thingy), how would I connect it to the PEX pipe? Here’s where the pricey (but not that pricey, compared to paying a plumber!) ¾” SharkBite-to-SharkBite connector I purchased saved my butt – I just stuck one end on the cut copper pipe going to the house, and then the PEX pipe into the other end.

I know there are many who insist that SharkBite connectors are just temporary fixes and that you need a more study connection, but many others who insist they never have problems with them over the course of many years. I decided it was worth it to give it a whirl to avoid soldering copper pipe, which is a messy and challenging method for many reasons (especially when you have a four year old running around as you work). And so far so good since I completed the project several months ago.

I then used a PEX threaded male adapter to attach the ¾” PEX to my new valve – along with a crimp using the PEX crimping tool to secure the PEX to the adapter. Unfortunately it took several tries (i.e. forever) to get the PEX pipe length correct, but eventually I got it (after screwing and unscrewing the adapters what felt like a dozen times, each time adding the pipe thread sealant and getting it all over my hands).

So then the moment of truth: turn the water back on! And TONS OF LEAKS!!! SHIT SHIT SHIT SHIT!!!!!!!!! Turned the water back off. Somehow composed myself. I then realized a critical lesson regarding SharkBite connectors – you must push the pipes in VERY FIRMLY to really get a no-leak complete and correct connection. Much more firmly than I expected. Whew, that solved that leak.

I then realized I needed to screw the PEX threaded male adapter much more fully into the valve using my pipe wrench. Finally I turned on the water and there were no leaks!!!!! I proceeded to run around my driveway screaming in ecstasy like a crazy person for all the neighborhood to hear.

Reveling in my accomplishment

We then of course had the blast radius of tools to clean up (another sign of my amateur plumbing status), which my wife very generously offered to clean up:

Below is the final setup, including the toad that decided to photo-bomb me (and which I didn’t see until I looked at the photo many days later):

The Cover Up

After all that work, I decided to watch it for a while to make sure no leaks developed, before somehow re-covering the valve and filling in the hole around the cover. You know, just a few days. Well, a few days turned into a few WEEKS of course.

Part of the delay was that I didn’t know how I would cover this new valve: the new valve handle is substantially larger than the previous small valve handle, so the original cheap PVC tube + cover would not work. When I finally made it to Lowe’s to look for a solution, low and behold they actually sold covers for this exact purpose! So I purchased a cover that seemed a reasonable size for my valve and for fitting around the meter valve cover and our neighbor’s valve cover.

One thing I knew in advance: I would have to cut out some chunks of this valve cover for it to fit correctly around the new valve and pipe. Fortunately I am now the proud owner of a sawzall (originally purchased for our back door replacement project, which maybe I’ll write a post about someday). With the sawzall and a couple firm clamps to keep the cover clamped to my work table, it was surprisingly easy to cut away a couple chunks of the cover for it to fit nicely around the valve and pipe (see pic below). Remember though, this cutting process is like a haircut: you can always cut a little more if needed, but you can’t easily add it back!

Then it was just filling in the hole around the cover, and the project was complete!

General Tips

Remember for a project like this to buy lots of backup / alternative parts from Lowe’s / HD / Amazon and return what you don’t need. E.g. if you’re not sure if it’s a ¾” or 1” pipe and thus you don’t know if you need a ¾” or 1” valve, buy both! And buy a bunch of different adapters for valves, pex, and copper. And buy various SharkBite connectors as further backup, in case you can’t figure out other connections. The penalty for not having a part you need in the middle of a project like this (remember, no running water in the house!) is MUCH higher than buying too much and having to return a few things. I ended up buying about $200 worth of parts and returning about $120 worth. And I would have been able to return more if I hadn’t had to re-do all the PEX and associated connections, but oh well.

Also a quick review for pipe wrenches: something I didn’t remember/realize is how these items work: they are designed to hold pipes in place and apply a torque in just one direction (which allows for easily removing and placing in a new position). So I found that while I purchased two pipe wrenches I couldn’t effectively use both, thus I used just one pipe wrench and a normal wrench. I did get better at using it eventually, but I recommend you look up good techniques for how to use it before employing one. Overall I was surprised they weren’t as simple to use as I expected.

Remember to get these connections tight with a wrench, and never trust your fingers will be enough. I know it sounds obvious, but I still forgot this at one point and of course the result was a leak. Further tightening with a wrench eliminated the leak.

Also remember (very important!): make sure you push the SharkBite connection on ALL the way. I did not do this initially (seemed like it was in as far as I could get it) and I had a bad leak. It took pushing it on much more firmly to get it to go all the way.

Also strongly recommend getting a SharkBite removal tool. We didn’t have one and thus we were forced to use an adjustable wrench instead (much much harder). In many situations you probably don’t have to worry about it (in fact there are non-removable SharkBite connectors that are less expensive), but unfortunately we had to remove the pex pipe from the SharkBite coupler two or three times as we were trying to get the length correct for the PEX pipe.

From what I’ve read, 3/4″ PEX seems to be the minimum size you want running into your house as the main water line. Do not use 1/2” pipes until you get closer to the individual faucets in your house.

I did a ton of research to identify the best online plumbing forums for asking questions, and I ended up identifying the two best sites as:

I posted on both forums about this project, and while I didn’t get a huge number of responses, they were mostly reasonably useful replies. Likely much better results than I would have gotten anywhere else online.

I was originally worried that if I had a twist-on cut-off valve, how would I ensure the valve ended up facing upwards when fully tightened? And thus accessible from above? I asked the same question on those forums, and no one answered the question, but in the end it wasn’t a problem. Either I got lucky or you can just adjust the valve towards the end of the tightening process to face the direction you want and it will remain watertight (i.e there is some flexibility in the orientation, as long as it’s wrench-tightened).


It was a hell of a project that took me about 4 to 5 hours of manual labor and many more hours of research, and I’m sure a professional could have done it in less than 30 minutes. But I seriously expanded my comfort zone, and developed a lot of great plumbing skills! I now feel dramatically more confident tackling other plumbing projects around the house, which is fantastic given how pricey a good plumber is.

TLDR: Concise Instructions



  1. Turn off the water to the house at the meter valve using the water valve “turnkey”
  2. Unscrew the coupler connecting the pipe to the water meter – and be careful to save the rubber gasket residing within the coupler (which both pipes will be pressed firmly against) for when you “re-couple” the pipes
  3. Unscrew the pipe between the meter and broken valve from the broken valve; you will likely need to use a pipe wrench and normal wrench
  4. Unscrew the broken valve from the pipe leading to the house, using your wrenches
  5. If you’re confident that the new valve is the same size / length as the previous valve:
    1. Apply some thread sealant to the threads of the pipe and then screw the new valve on to the pipe leading to the house – I strongly recommend buying the highest quality “pro-grade” ball valve you can find at your hardware store or amazon, as you want to minimize how often you have to replace this valve
    2. Apply some plumbing connection liquid to the threads of the pipe that lives between the water meter and valve, and then screw that pipe into the new valve
    3. Align the pipe with the output of the water meter, placing the rubber gasket appropriately between them, and then screw on the coupler to firmly connect the two pipes
    4. Turn the water back on at the meter, check for leaks – and if you do have leaks, odds are there is a connection that just needs more tightening
  6. If you’re confident the new valve is sufficiently different in size / length versus the previous valve that the original piping is no longer a workable length (or you do the above steps thinking it will work and it doesn’t, as happened to me):
    1. Use a copper pipe cutter to cleanly cut the copper pipe leading to the house, as close as practical to the adapter
    2. Attach a SharkBite-to-SharkBite connector (the same size as your pipe, very likely 3/4″), pressing FIRMLY (more firmly than you might expect)
    3. Measure carefully how long the PEX pipe should be, erring on the side of a bit long (it’s much easier to cut a little more off if needed, like a haircut), and use the PEX cutting tool to cut it that length
    4. Press the PEX pipe into the SharkBite connector FIRMLY
    5. Connect the PEX to male threaded adapter to the PEX pipe, and then use the PEX crimping tool to squeeze a crimp ring around the PEX pipe at the adapter, creating a super stable and waterproof connection
    6. Apply some thread sealant to the threads of the adapter and then screw the new valve on to the adapter, using your wrenches to ensure a tight connection
    7. Apply some plumbing connection liquid to the threads of the pipe that lives between the water meter and valve, and then screw that pipe into the new valve
    8. Align the pipe with the output of the water meter, placing the rubber gasket appropriately between them, and then screw on the coupler to firmly connect the two pipes
    9. Turn the water back on at the meter, check for leaks – and if you do have leaks, odds are there is a connection that just needs more tightening, and/or the pipes were not pressed into the SharkBite connector firmly enough (both were problems for me)

If you find that the pipe still doesn’t fit (too long):

  • Remove the PEX pipe from the valve by unscrewing the PEX to male adapter
  • Remove from the SharkBite connector using the SharkBite removal tool
  • Slice a small amount off the PEX pipe
  • Reattach to the Sharkbite connector (FIRMLY) and the new valve
  • Assess if the pipe now fits

If you find that the pipe is now just slightly too short, unfortunately you’ll need an entirely new segment of PEX:

  • Remove the PEX pipe from the valve by unscrewing the PEX to male adapter
  • Remove from the SharkBite connector using the SharkBite removal tool
  • Cut a new slightly longer stretch of PEX pipe
  • Attach to the Sharkbite connector (FIRMLY)
  • Use a PEX crimp removal tool to remove the current crimp from the PEX to male threaded adapter (destroying it, but they are relatively cheap, unlike the adapters)
  • Attach the new PEX pipe to the male threaded adapter using PEX crimping tool and a fresh crimp
  • Screw the male threaded adapter into new valve
  • Assess if the pipe now fits – if now slightly too long, see above instructions

One comment on “Replacing Your Main Water Line Cutoff Valve
  1. Rob Olson says:

    Impressive achievement!!! You were meant to be a plumber!!!!!

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