everytime I turn on my hot water in my bathtub I get no pressure. water pressure is fine in all other faucets in the house. what causes this? & how can I fix it?
First thing to do, if you can get to it, it to check the screens on the valve.
What kind of tub filler valve do you have? Brand and model would help. Could be lots of things - bad seals, dirt...something broken. A model would help.
The most likely cause is debris in the stem/cartridge/disc (whatever you have). The water needs to be shut off and the valve disassembled, cleaned, and the lines flushed. You may need to replace the stem/cartridge/disc (whatever you have). If you do not feel comfortable doing this, call a licensed plumber.
Deb
The Pipewench