Help with connection Pex to copper to shower valve

We're about done with our current bathroom project, which was gutting everything except the shower insert.
I bought a shower "kit", which was everything to replace the shower plumbing to all oil rubbed bronze hardware. When I went to remove the old single shower control and valve, I found that the plumber soldered the copper pipes to the shower valve instead of using the threaded ends. Unfortunately, the horizontal lines going into the valve are too deep in the access hole in the shower insert, that I can't get anything in there to cut the old valve out.
My only option to get the valve out is to cut an access panel in the drywall, in the opposite wall, which is our bedroom, but that's ok because the bedroom is our next project, and I can repair that hole then.
Once I get the old valve out, my question is on how to properly put the new valve in. I have Pex lines coming up from the basement, (which I have complete access to because the basements unfinished), going up the 2x4 wall framing, and going into copper "L's" that run to the valve body. I don't know that I can get to the vertical Pex lines in the wall that connect to the copper "L" fittings. So is my best bet to cut the Pex lines in the basement, use couplings down there and run new Pex lines up the wall, then some sort of threaded connection to connect to the valve?
Does it have to be copper connections at the valve, or does Pex offer some sort of threaded coupling that I can run directly into the valve body?

Thanks for any help.

Any other suggestions I'm not thinking of?

There are several connection options to select from and they are available by entering "Pex to Copper connection" in the google search engine.

Posting photos may narrow the opinions.

In my opinion,

The above mentioned methods are good and I will add a half inch shark bite coupling will attach half inch PEX to half inch Copper directly with no tools.

http://www.homedepot.com/s/plumbing+access+panel?NCNI-5

Make sure you use copper to run from the valve to the tub spout, not PEX or steel pipe.

Now would also be the time to add ball valves to the supply lines so the whole house would not have to shut down to service the shower valve in the future.

bud16415 said:

The above mentioned methods are good and I will add a half inch shark bite coupling will attach half inch PEX to half inch Copper directly with no tools.

Click to expand...

sorry Bud, I love ya like a brother from another mother.:beer:

but shark bite ? NO NO NO NO...

either solder that copper or use a compression fitting. NEVER use a shark bite in a covered up application, YOU WILLL see it again lol:rofl:

If you go with JoeCaption's plan, the ball valve could be the transition point from pex to copper (pex into the valve, copper out).

frodo said:

sorry Bud, I love ya like a brother from another mother.:beer:

but shark bite ? NO NO NO NO...

either solder that copper or use a compression fitting. NEVER use a shark bite in a covered up application, YOU WILLL see it again lol:rofl:

Click to expand...

You may be right and most likely are. You are a pro my brother. I used a few on my house the flex adapters on the top of the water heater took them and the laundry room already had good looking copper running to it so I chopped them off in the basement and did the pex to copper Shark Bite. They are out in the open and will be tested now close to two years without a drip. I know how that works though with Murphy’s Law if I stuck them in a wall they would leak as soon as I had the wall covered in tile. I would never build a bath without access panels from the back. in my case it was done in PEX so I just hooked it up from below.

The same type fittings as shark bites we use all over the plant with great success and never see any leaking. The main thing I don’t about them is the cost. They make every adapter you can think of between PEX and anything else so it shouldn’t be hard to hook up.


Say hi to Mom for me.

Thank you for the replies. As far as the suggestion to google the issue, I did do that, but have found many suggestions. I've also found some people talking about brittle shark bite connections that are known to break, so I just wanted to get a consensus on how to do this the correct way.

The problem with installing a new valve is bigger than I thought when I posted the question. I was thinking I just needed to figure out a way to replace the water lines into the valve, but if you all suggest copper to the shower head and tub, then I have to figure that out also. As stated, all four copper connections into the shower valve are soldered, so I'll have to figure out the run up to the shower head and tub fill also.

I'm hoping to get to this during the week, so I can post pics of the valve in the shower itself, and a pic of the access hole I'm going to have to cut in our bedroom wall.

Thanks again for the help.

if you have access below the floor to these two pipes there I would adapt to pex and leave the shower for another day.

Looking ahead to your bedroom project, you can use this to create access to the shower valve in the future>
http://www.lowes.com/pd_115086-138-34059___?productId=3130139&pl=1&Ntt=access+panels#BVRRWidgetID

However, back to the beginning, had anyone ever mentioned to you that faucet mfg. offer trim for their faucets, that is interchangeable, solving a good portion of your issues.