How do I replace a shower/tub faucet?

July 7, 2007 10:43 PM

How do I replace a shower/tub faucet?

My shower handle snapped off this morning, at the cartridge, in the on position. After turning off the whole house valve and taking the broken handle apart, it looks like its time for a whole new shower assembly. Partially because I am sick of the hideous shower I have, and partially because things appear really broken with the existing system.

I purchased a plumbing book from Home Depot and searched the interwebs, but am running into issues not addressed thus far.

The old valve uses a cartridge (Moen faucet). However, the cartridge seems to be permanently bonded to the valve, even after removing the metal peace that holds it in place, it won't budge.

The valve used looks like its probably not being used in modern faucets anymore. The vertical pipe connects behind the horizontal pipes, where all the valves I looked at on Moen's site look like they're in line, so I suspect this is an old design that is no longer used. This leads me to believe the copper pipe will need to be replaced and made to match up inline.

The piping is 1/2 inch, the shower I like only comes in 3/4 inches connections. I'm not sure if the 1/2 piping can be replaced or adapted.

The bath/shower walls are tile. I really would rather not replace the tile as I like the way it looks and also am not interested in forking out the dough to replace it. HOWEVER, coming through the back to get to the piping isn't an option, as the wall on the other side is the kitchen wall with cabinets. I do have 15 spare tiles (its 6"x12" tile) but the only info I've been able to find talks about a new tile/shower installation, not trying to fit into an existing one.

So I really don't know where to begin. Everything I've found so far either addresses new installations, replacing minor components, such as a new handle, or having some back access which I don't have. I'm not sure if that means I'm going to have to rip everything out and start from scratch, or if I am just overlooking information that pertains to my situation.

Any suggestions and advice on how to approach this project would be greatly appreciated. I'm moderately handy and between my husband and I we do most of the home repairs ourselves, usually successfully. However, this is the most complex plumbing issue either of us has faced.

posted by [insert clever name here] to home & garden (8 comments total)

Can you post some pictures? I dealt with a Moen shower faucet with cartridges years ago, but I can't remember exactly what I did. Maybe a photo will jog my brain, or at the very least help someone who knows way more than me about such things.
posted by The Deej at 10:55 PM on July 7, 2007

Dunno if this will help, but it's worth a shot.
posted by The Deej at 10:57 PM on July 7, 2007

Sorry, the above links to a fee-based instruction thingie. Last resort only. :)
posted by The Deej at 10:59 PM on July 7, 2007

This might not be the right model (don't know how many there are) but cartridge puller comes up a lot in googling "cartridge faucet moen".
Depending on the faucet model moen has this installation help page. Section 4a covers a single handle shower valve, and they show a small plastic adapter to use with an adjustable wrench to remove the cartridge.
posted by sailormouth at 11:23 PM on July 7, 2007

This may help.
posted by weapons-grade pandemonium at 12:13 AM on July 8, 2007

First of all, if you can possibly replace your cartridge, and be satisfied with your existing Moen valve, your problem is going to be 1% the size of re-fitting a new valve. You can get common Moen cartridges like the 1225 B, which is used in many Moen shower sets like the 2205 for under $20, and even the special little white plastic tool you need for changing them is included (as sailormouth mentioned - the chrome tool sailormouth linked is generally for maintenance people or plumbers who change a lot of Moen cartridges, and don't want to fool with the little plastic thing). You can be in and out of this repair in under an hour. The Moen site also has a great valve model identifier page, and you can order parts direct from Moen, if your local plumbing distributor doesn't carry them, for some strange reason. General instructions for doing this are on the Moen site, although they appear to be for a bathroom sink, instead of a shower. The cartridge is the same, however, and its assembly/disassembly procedure is identical, whatever the application. Unless you feel you absolutely need something like a temperature limiting Posi-Temp valve or something, and are prepared for the work and expense of re-plumbing, this option is definitely the one to pursue. But if you just must re-plumb, read on.

When it comes to piping, if your bathroom is plumbed in 1/2" copper, you'll need to stay with 1/2" valves and hardware, as putting in 3/4" valve components with reversed reducers is likely to introduce burbling. 1/2" pipe should easily support 2.5 gpm flow limited shower heads, and higher, if your jurisdiction allows such. Staying with 1/2" pipe also reduces loss of heat in the hot water line delivery, vs. 3/4" piping. If you simply must have 3/4" lines, don't cheap out, and go all the way back to wherever you have 3/4" line before it is reduce to 1/2". As a quick check, go look at your water heater to see if it is plumbed as 3/4" (few residences are this way). If your hot water heater is 1/2" as 90+ per cent of North American homes are, forget 3/4" lines.

If you can avoid changing your piping, in the main, you can probably work a new valve assembly in, without ripping out your tile, although it will be a quasi-frustrating, knuckle bruising exercise. The key is to remove your existing valve, and take it along when shopping for a new one, with a hole pattern as similar as possible. If you simply can't find a new valve assembly with a usable hole pattern, and have to re-pipe, abandon any thought of saving your tile work, and just get started with demolition, on the bathroom wall side. If you've never done this before, plan on 4 to 5 full days for the rework. 1 day for demolition, 1 day for re-plumbing, 1 day for repairing and leveling wall board (use Wonderboard), 1 day for tiling/grouting, and 1 day for cussing.

You might be able to just work with a construction hole from the faucet up to the shower head, if your riser pipes can be worked. This is worth trying, but don't compromise your plumbing work trying to save demolition effort, as poor plumbing will eventually cause you to go back in.
posted by paulsc at 12:20 AM on July 8, 2007 [1 favorite]

Thanks paulsc, you've given me a lot to consider.

The cartridge in question is the 1222. That site has removal instructions, but the part they show using a pliers to grip to is what snapped off. Other attempts to remove it have failed. I have to wonder if there wasn't some retrofiting going on, as the valve shown in the illustrated parts digram the linked here doesn't look anything like the one I have. It lacks the shutoffs on the sides (which would have been ever so useful) and as I mentioned above, the vertical and horizontal pipes are not in alignment like that.

Even if I can get the cartridge out though, not sure if I want to go that route. I hate Moen. This is the third faucet of their faucets that had a handle just snap off. Maybe that just happens, but I really don't think it should.

So, if I decide I need to replace the valve to go with another brand:
The existing hole in the tile is extremely small. 2"x3" rectangle. I started last night to enlarge it as that's what the new faucet called for (before I realized the incompatibility issues.) The saw blade I was using though was long enough I had to stop before it hit the horizontal pipes which are pretty close to the wall. Assuming I can figure out a way to get it open enough to get the valve out, what kind of concern do I have with the pipes not being in alignment?

I know copper has some flex, can I move the pipes to be in alighment? The vertical piping is about 1.5 inches behind the horizontal pipe. I would assume thats a pretty significant amount to move it and would be bad without bends, but I don't know that there would be room to put bents in with just a hole....

Finally, the construction hole you mentioned, I assume you mean you'd take out the tile and backerboard around where I need to access, and replace. Assuming that's what you mean, I do have enough tile to expose all of the piping from the top of the tub to the showerhead. Would I be cutting out the tile and backerboard along the grout line of the tile to be removed? (I would assume?) And when I replace it, how do I seal new backerboard in there? I've done drywall repair, but I'm not able to see in my head how I would be able to line up, tape, and seal the new board if the remaining tile is flush with where the edge of the board is.

Or, maybe I remove the tile separate from the backerboard, and cut a slightly smaller hole in the backerboard?

Or am I completely misunderstanding what you mean by construction hole?
posted by [insert clever name here] at 5:27 AM on July 8, 2007

"... Or, maybe I remove the tile separate from the backerboard, and cut a slightly smaller hole in the backerboard? ..."

That would be what I would try, first. How successful you will be depends to some extent what kind of adhesive was used in the original tiling, and what kind of backer board you have. This article describes the process. Removing all the grout around tiles you'll be taking off is the key. Remove enough tiles to have a 1/2 tile overlap where you'll seam. You don't really have to tape and mud like you would to finish drywall, if you're tiling over the repair.
posted by paulsc at 8:44 AM on July 8, 2007