Q. Is there something that I can do to prevent my shower from running hot when someone flushes a toilet or turns on a another faucet in the house. This can be very frustrating and I’m concerned that it gets so hot that it could cause an injury. Can you tell me why this is happening and is there a fixture that I can purchase or fix myself?
A: This happens in some older homes due to the water lines in the house being undersized, or if the cold water line has been routed to the toilet right before the shower. When you flush a toilet, it can “demand” all of the cold water in the system and leaving you with scalding hot water coming out of the shower. There are newer shower valves available that are pressure sensitive however; this is not a simple cartridge that can be installed to your existing faucet or shower fixture.
To have a new pressure/temperature sensitive shower fixture installed, you’ll require a plumber to cut into the wall behind the shower and this will also require the wall to be repaired after the installation.