The hot and cold water in my bathroom works fine, but the shower in the same bathroom has NO hot water.

Why is this happening, and how can it be fixed?

Sounds like a clogged hot inlet, one handle or two?

I am not sure if this is considered one handle or two. Please see pictures at Home Stuff - dm2000's library

If it's not a clogged inlet, what else could it be?

How would I fix this?

If you have hot water everywhere else a clogged cartridge inlet is the most likely problem. Do you feel cup to taking the valve apart?

Check the temperature setting on your hot water heater. If all is fine, the next thing to consider is whether a fuse has been blown or tripped.

Post #1 states the hot is fine in the bathroom.

SpaParts - the hot and cold water is working in the sinks in the same bathroom, but there is no hot water for the shower / tub.

ballengerb1 - "If you have hot water everywhere else a clogged cartridge inlet is the most likely problem. Do you feel cup to taking the valve apart?"
What is the "cup"? How do I take the valve apart? The faucet / shower is Groche brand.

Sorry, typo. Do you feel up to taking the valve apart. I will find you a manual

ballengerb1 - Ok. I look forward to reviewing the manual.

How much do you think it will cost to fix or replace the clogged cartridge inlet?