Hot water in sink but not in shower.how to fix problem?

Hi Bjyoung

Do you have water coming from the hot side and it isn't hot or is there NO water when you call for hot water? Also, let us know the name brand of the shower valve and how long it has been since it was last used.

Back to you...

Mark

Check the internal cartridge which regulates water flow and temperature. Before you begin disassembling the shower valve, ensure that you don't have a problem with the hot water heater.

Since youhave hot water at the sink we know your heater is doing its job. Most likely debris in the hot inlet of the mixing valve. If you can post a pic of the valve or give us a model/brand we can walk you through how to clear the cartrdige.

I agree with Bob, please tell us the brand and the model number of you shower valve, Thanks.

John