The handle that switches the water in the tub from tub fill to shower has gotten increasingly hard to turn. Now even with two hands I can't turn it on. Do I have to replace the whole thing?

Thanks for any advice,
cma

The handle that switches the water in the tub from tub fill to shower has gotten increasingly hard to turn. Now even with two hands I can't turn it on. Do I have to replace the whole thing?

Thanks for any advice,
cma
It would have been helpful to have known the brand of valve but I've put up a faucet similar to yours, (see image).
Loosen down the top nut and see if that helps. No? Then unscrew the large nut next to the valve body and back the stem and washer assembly out counterclockwise. Clean up the threads and coat them with Plumbers Heat Proof Grease that can be picked at an y plumbing store. Now reassemble, turn better now? Good luck, Tom

Humm, sounds like another chore for my brother-in-law on the next visit. I thought it might be something I could do myself, but I'd hate to be without bathing facilities until he and my sister come for a visit next week.

Thanks for the diagram, plumbing is not his forte but he is able to do minor things for me.

cma

Did you remove the handle and cover and loosen the bonnet packing nut? That's the top nut on the stem. Regards, Tom