I have a single lever shower faucet with no cold water coming from it.
Worked fine yesterday, not working at all today.. what is the problem? How do I fix it?

Hi Arrina...

Most likely the cartridge assembly of the shower valve has gotten plugged up with something.

Your best bet here is to shut off the water supply (hot and cold) to the shower valve and then remove the handle/trim and get to the cartridge assembly for removal. Pay attention to any geared parts so they go back in the same way you removed them.

Pull the cartridge and clean the unit. Pulse the water flow on for a few seconds (hot and cold) being sure to cover the valve with a towel so you can clear the lines of any sediment/debris that may be stuck in the lines.

Reinstall everything and test your work. If that fails to fix things you will probably need to purchase a complete replacement cartridge for the shower valve.

Questions? Let me know...

Mark