Roman Tub Valve

Hoping someone can help. I replaced a roman tub valve in which the existing valve was supplied with 3/4 in pipes and the new one is 1/2 inch. I reduced the copper lines to use the new 1/2 valve and it seems as if the volume is too much and the new valve constantly leaks even when shut off. any ideas?

 

Welcome to the forums.

You could leave a link to the faucet/valve you used.
Reducing 3/4" pipe to 1/2" will not cause a faucet to leak. Whether there is 3/4" or 1/2" connected..... the pressure is the same. It would appear there is a problem in the faucet.valve.

 

If you sweat those pipes on and got the valve too hot, its possible that you could have got the valve too hot and melted something in the cartridge.

I will generally take 2 FPT fittings, sweat a short piece of copper pipe onto each one along with an elbow, then once they are cool, screw them onto the valve. It keeps the heat of the torch several inches away from the valve when you go to hook it up.

Most valves will instruct you to disassemble the valve before sweating.

I have also seen brand new valves leak. The plumbers I had doing my last bath remodel had this same problem with the shower valve, even though it was new out of the package. Course, maybe they didn't disassemble it... I wasn't watching over their shoulder.