Why is there no water coming out of any hot water faucet?

There could be a lot of reasons. Hot water entry point clogged, hot water heater out, Hot water line broke or not hooked up. If this problem has only happened since the shower has been replaced or serviced, the chances are that there is a hot water safety that just needs to be adjusted. Take off the handle, look at the assembly, you should see a plastic sleeve or knob that can be turned. This knob stops that handle from turning past a certain point which restricts the flow of hot water.