If your faucet lacks an anti-scald valve, you can replace a standard cartridge in an older valve with a new anti-scald cartridge in some cases. Because scalding water can be painful and dangerous, plumbing codes often require new tub and shower faucets that prevent the flow of very hot water. Some temperature-balancing or anti-scald faucets prevent cold water from being turned off; others have a thermostatic device that reduces hot water flow when necessary. Check that yours has an anti-scald valve, which is usually marked. Sometimes by rocking the faucet, you’ll hear a click that indicates the unit has an anti-scald valve.
