Shower water not as hot as rest of house

[lacey302]

I recently installed a new electric hot water heater and the tub/shower water does not get as hot as the rest of the house. I have adjusted the thermostat but the water still only gets moderately hot. The water heater is directly behind the shower so I know it's not a location issue. Any ideas what the problem could be?

Thanks!

[phishfood]

This problem only started after the water heater changeout? If so, my first guess is that some debris or sediment became lodged in the cartridge of the shower valve.