I went to use a seldom used bathtub/shower in my home and it has no hot water. The cold is fine but when I turn the dial to the hot side the flow of water suddenly stops. The sink beside the tub has hot water and operates correctly. I'm in a fairly new house (about 4 years old) and have used this tub very little. About a year ago I had some friends with septic problems use the shower so I know it worked then. Because it is seldom used I can't pinpoint when problem started. All I know is it was fine months ago and now it doesn't work. Any ideas? Thanks.

What's the brand name of your mixing valve? Regards, Tom

Sorry, don't know much about plumbing, so don't know what a mixing valve is. The faucet is a Moen.

sorry, don't know much about plumbing, so don't know what a mixing valve is. The faucet is a Moen.

Thank you! A mixing valve is just another way to describe your faucet, (called because it mixes hot and cold water.)
You have trash that's clogging the inlet ports of your cartridge. Shut the water off to the faucet and open it up,( see instructions.) Check and clean the inlet ports. Before you reassemble turn the water back on for a minute to flush out the supplies. You should havge a strong stream of hot water when you do this. If not get back to me . Good luck, Tom

The PDF looks very helpful. I'll try that. Thank you very much speedball1.