Anti-Scald Tub and Shower Valves are required by code to be installed in all new installations and would be a recommended upgrade on existing installations. Did you know that 30% of all burns treated in emergency rooms are due to scalding? 130-degree F water can deliver a 3rd degree burn in only 30 seconds with hotter water doing it even quicker. 160-degree F water can deliver a 3rd degree burn in only one second. Especially vulnerable to scalding are the elderly, young children, handicapped individuals, and those who suffer from seizures. Anti-Scald tub and shower valve come in two types that offer protection from changing water temperatures. The two types are “Pressure Balanced” and “Thermostatic” valves, which regulate the temperature to a nearly constant setting without surprise temperature fluctuations occurring when water is used elsewhere in the home. These valves also have a maximum setting where they can be set not to go past a predetermined safe setting creating a great degree of safety against anyone being scalded while using them.
Pressure Balanced Anti-Scald Valves
Pressure balanced anti-scald valves operate very similar to the conventional valve we have been using forever where you open or, close the hot and cold valves to regulate the temperature to one where you are comfortable. The new pressure balanced valves still operate in that same manner but with a single handle controlling the temperature. Initially when you turn on the valve it flows fully open cold then as you continue to turn the valve the hot water is introduced in a low amount and the cold is gradually decreased. As you continue to turn the valve you get more and more hot water and less cold until you reach the desired setting. Continuing to turn the handle you should reach a limit stop which is set at the safe maximum temperature and you cannot select the water temperature to be any higher. The difference with pressure balanced valves is that once you select a temperature the water temperature should remain very close to the temperature you selected even if someone else in the house used a large volume of water such as filling a washing machine or turning on a dishwasher. A pressure-balancing valve will detect the loss of pressure on either the hot or cold and move to limit the water on the other side matching the pressures to maintain a nearly constant temperature at your setting. Most pressure-balanced valve will maintain a steady temperature with in about plus or, minus three-degrees F of where you set the temperature. You may notice a slight decrease in flow sometimes when the pressure-balancing valve is doing its job. The Moen Posi-Temp, Moen-Trol, Symmons Temptrol, and many of the Delta tub and shower valves being popular choices for pressure balanced valves. Prices for decent brand name pressure balanced valves start as low as just under $100.
Thermostatic Anti-Scald Valves
Thermostatic anti-scald valves operate quite differently from the pressure-balanced valves. The thermostatic valves function involves an active sensing mechanism that detects the water temperature and constantly closes or, opens the hot and cold supplies to maintain a constant set temperature. Usually thermostatic valves have two knobs one of which turns on the water and controls the flow volume, and the other, which adjusts the temperature setting. Many times the temperature selection knob will even have the settings labeled in degrees. This gives you the ability to set the temperature where you like it and never have to touch it again year round your shower will always be the same temperature. Thermostatic valves will often maintain a temperature of plus or, minus one-degree F. Clearly the performance and features of thermostatic anti-scald valves are a higher level of performance than pressure balanced valve and with that comes a higher price tag often in the $300 range for the lower priced ones. Some of the popular brands include the Moen Exact-Temp, the Delta R-10000 valve body with the thermostatic cartridge option, Grohe and a number of others.
All of the Anti-Scald Valves should be considered when the old tub/shower valve either need replacing or, repairing as they afford a level of safety and comfort that your old valve cannot possibly match.