Showers with separate hot and cold valves were nixed by the building codes about twenty years ago, in favor of a single-handle anti-scald valve that prevents the water temperature from rising above 120º F (IRC 2708.4). The statistics on scalding injuries in the U.S. back up the building officials’ decision for the new standard:

• More than 20% of all burns are caused by scalding water.
• Over 2,000 children are burned by scalding water each year, mostly in the kitchen and bathroom.
• Scalding can lead to other injuries, such as falls and heart attacks, especially for the elderly trying to escape a stream of super-hot water.
• 160º F water will scald your skin in half a second.

    Anti-scald shower faucet valves reduce the danger of burns by automatically adjusting to sudden changes in the pressure and flow of the water supply lines, using a diaphragm or piston mechanism to continuously balance the hot-to-cold water ratio. You can fine-tune the temperature of the water with a rotating mechanism inside the unit if you want the water a little hotter or colder.

   While anti-scald valves are one safety precaution to avoid hot water burns in the shower, another strategy is to set your water heater thermostat to 120º or 130º F (the “low” to “medium” setting); so that the hot water coming out of any faucet in the house will not quickly scald bare skin—even at straight hot. 

    Also, see our blog posts When were shower control valves first required by code to be pressure balanced and temperature limiting? and What causes low water pressure in a house? and How do I get rid of the sewer gas smell in my house?

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Here’s links to a collection of our other blog posts about PLUMBING:

• What can I add to my septic tank to help it work better? 

• Why is there mold inside my toilet tank?  

• What are the pros and cons of a wall-mounted toilet?

• Which plumbing fixtures require water shut off valves in a home? 

• How can I tell if a house is connected to a septic tank system or sewer?

• Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water? 

• Why is a backflow preventer required on lawn sprinkler systems? 

• How can I locate my septic tank?

• Is a hot water faucet handle required to be on the left? 

• Can you live in a house while the plumbing is being replaced?

• Why is the European-style bottle trap not approved by the plumbing codes in the U.S.? 

• Why can't PVC be used for water pipe inside a house?

• What are the common problems to look for when the plumbing has been replaced in a house? 

• What's that powdery crust on the pipe connections at the water heater? 

• How can I tell what type of plumbing pipe I have? 

• Should I call a plumber or septic tank contractor when my septic tank backs up into the house? 

• What are the pipes on my roof? 

• What does polybutylene pipe look like? Why is it a problem?

• Which water pipes are an insurance problem and possibly uninsurable? 

• Does a home inspector check the plumbing under the floor slab?

• Is it alright to disconnect the washing machine drain from the septic tank and divert it to the ground in the yard?

   Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.