Good Afternoon

My hot water in the shower and tubs is very low.

What can I do?

If the problem is with a shower or tub faucet, you may have a problem with the anti-scald valve. This is a feature of modern faucets that prevents a blast of hot water in the shower when some thoughtless (or sadistic) person flushes the toilet down the hall! It is basically a spring-activated valve that senses a drop in cold water pressure and immediately reduces the hot water pressure. These valves can become defective with age and with exposure to chemicals in the water causing a reduction in water flow to the fixture. Some faucets have the anti-scald features integrated into the valve cartridge while others have a separate anti-scald valve. In either case replacement of the defective part is the repair of choice.

Does sink in bathroom have normal pressure -- if it does anti-scald valve may be problem

With sink faucets, the two most common causes of low pressure are 1) one or both of the shutoffs are partially closed or 2) the aerator screen has become blocked with dirt particles. Sometimes the aerator screen can be cleaned, though replacing it is usually the better choice. It the aerator is old and has not been disturbed for years, chances are you will damage it during removal. In either case, replacement of the aerator with a new one is an inexpensive and complete repair.