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Don’t Get Burned – Let An Anti-Scald Valve Take The Heat

I’ve gotta tell you, I love hot water – hot showers, hot baths, hot springs, steam baths, you name it. Heck, I even take my morning cup of tea extra hot. But while I have a pretty high resistance to heat, even I’ve gotten burned on occasion by an extra hot tap or a poorly timed mid-shower toilet flush. Increasingly there are regulations on new construction to try to prevent burns from hot water, but if you live in an older home with plumbing that hasn’t been updated in the last 5-10 years, you probably don’t have any of the newer, relatively easy to install anti-scalding safe guards. Especially if you live with older people who might be startled by a sudden change in water temperature and slip and fall, or small children whose thin, sensitive skin burns more easily, you might want to look into installing an anti-scald valve.

A Water Heater Valve Will Look Something Like This Shower Tempering Valve From Pfister, Only With A Cap Instead Of A Pointed End
A Water Heater Valve Will Look Something Like This Shower Tempering Valve From Pfister, Only With A Cap Instead Of A Pointed End

There are several different kinds of hardware designed to keep water at a safe temperature, and they install in various parts of your house. The very most important first step, and the easiest one, is to simply turn down the temperature on your water heater to no more than 120 degrees Fahrenheit, if you can. This will keep all the water in all the taps in your home from putting out water any hotter than that. However, installing a mixing valve or Tempering Valve between your water heater and your main house supply line can be a better option. This valve mixes the heated water with cold water to a temperature you set, which will stay consistent throughout your whole house. This allows you to keep your water heater at a higher temperature, which means you need less of it to get the temperature you want – which, in turn, means longer or more showers before the water heater runs cold, making this an excellent option for a larger family.

American Standard 605xtmv Thermostatic Mixing Valve Anti-scald protection
American Standard 605xtmv Thermostatic Mixing Valve Anti-scald protection

Another good reason to keep your tank at a higher temperature (at least 140) is that the hot water disinfects your water heater and the pipes it travels through, preventing the buildup of harmful bacteria.  However, if you’re going to keep your water heater at a higher temperature, you definitely want to install some other secondary anti-scald measure to make sure you don’t get burnt. Point-of-use valves like this American Standard work a little differently. Rather than attaching to or near your water heater, these ones temper the water between the hot and cold supply lines to your tap, tub, or shower.

Danze Single Control Pressure Balance Mixing Valve - This Is What The Guts Will Look Like Without The Handles
Danze Single Control Pressure Balance Mixing Valve - This Is What The Guts Will Look Like Without The Handles

There are two types of point-of-use anti scald valves. The first, a pressure balanced one like Danze Mixing Valve, functions fairly simply. If you’ve ever gotten fried or chilled out of a shower by someone turning on a tap or flushing a toilet, what’s happening is that the water in your house is diverting to feed their tap, dropping the water pressure of that temperature and changing the levels of hot and cold in the one you’re using. A pressure balanced valve senses this change as it occurs, and compensates for it by changing the flow of the other temperature supply, so if all the cold water is gone, you won’t be left with pure hot water. If the cold water supply is cut off entirely, the whole shower will drop to a trickle until the rest of the water comes back.

Elkay Anti-scald Thermostatic Mixing Valve with Compression Inlets and Outlets
Elkay Anti-scald Thermostatic Mixing Valve with Compression Inlets and Outlets

The second type of point-of-use valve is called a thermostatic valve, which look something like this one from Elkay. These are actually much more similar to the kind you install next to your water heater. They sense the temperature of the hot and cold supplies, mixing them to a temperature you can adjust from inside the shower without allowing it to get hot enough to burn. This allows you to run much hotter water to other parts of your house while keeping your shower safe to use. On the plus side, this type of valve doesn’t shut off when someone somewhere else in the house flushes, but they are a little pricier than the pressure balanced type.

Rohl Exposed thermostatic Shower Mixer
Rohl Exposed thermostatic Shower Mixer

Thermostatic valves can be installed directly into your piping, but also often come built into shower and bathroom faucets. Those designed for the shower, like this Exposed Shower Mixer, typically come with two handles rather than one – the first to control water volume, and the second to control water temperature, rather than the traditional single knob or hot/cold duo. With this one, the water is actually mixed in the faucet itself as opposed to in a valve behind the wall, which gives it a pretty cool steampunk look.

LaToscana Double Handle Thermostatic Valve Trim Kit with Scald Guard
LaToscana Double Handle Thermostatic Valve Trim Kit with Scald Guard

The best ones, like this one from LaToscana, will actually have temperature markers on the second handle, to allow you to adjust the temperature by actual degrees rather than just by feel. The sensor will react to the water temperature and maintain whatever you set it to within 1-3 degrees, depending on the model. Where a typical shower handle mixes hot and cold at a static volume, a thermostatic faucet mixes by temperature.

Speakman SentinelPro Anti-Scald Thermostatic Pressure Balanced Shower Valve
Speakman SentinelPro Anti-Scald Thermostatic Pressure Balanced Shower Valve

Ones with one handle, like this SentinelPro, tend to be the pressure-balanced type of mixing valve, and are best suited for low-flow showerheads, which are especially sensitive to fluctuations in water pressure.  Because you will usually have the water turned all the way on to maintain a usable pressure, any change in flow (like from a toilet flush) would dramatically change the temperature of the water. This kind of faucet, again, will turn the water down to a trickle until both hot and cold water pressure return to normal, to keep from burning you.

Royale Thermostatic Valve Trim
Royale Thermostatic Valve Trim

Some single-handled versions do come in thermostatic rather than pressure-balanced. This valve knob from Herbeau’s Royale Collection adjusts between 55 and 115 degrees Fahrenheit and can maintain water pressure even if there’s demand elsewhere in the house. However, this is one of those items that you definitely feel the price difference, and have to pay for what you get.

Whichever type you opt for, a little box out in your furnace room, a brand new shower faucet, or anything in between, I really do think this is an important project to undertake. Hot enough water can burn just as badly as fire, and when it’s so easy to take preventative measures, there’s really no reason not to. So if your taps run a little hot, or if a temp change has ever made you shriek in the shower, don’t wait for a really bad burn to inspire you. Just get your favorite plumber on the line, and trust me, you’ll bathe a little easier.

Have you ever suffered a really bad burn in the bathroom? What’s making you consider anti-scald safeguards? Do you prefer the safety of a low temperature throughout your home, or the convenience of a nice long, hot shower? Let me know in the comments!