Consider me spoiled when it comes to using scald-guard style shower faucets. So much so that my recent experience, repeated each day for four days, using a two-handle shower faucet installed in 1985 was a stark reminder of how far anti-scalding faucet technology has come.
The shower was 3' × 3' with handles extending out 5-in. — far enough outward to be inline with a bather's elbow, and it didn't take long for me to basically strip the skin off my back with scalding hot water after bumping into the cold handle. The second day, I did my best to avoid any elbow contact, but didn't count on having someone flush a toilet in another bathroom. By the fourth day, I swore that if I had a demo-saw, that bathing module and I would have a demo-date.
Live and learn
In the process of getting scalded several days in a row, it struck me that the few seconds of waiting for the change in water temperature seemed like an eternity.
You can't turn down to 120°F what is already set for 120°F! If I hear one more “expert” tell folks to turn down their water heater to 120°F for safety, I'm going to scream bloody murder. News flash: it came from the factory set for 120°F, and so did this particular electric water heater that was delivering 147°F. Even if it had been delivering 150°F, it would have been compliant with American National Standards Institute regulations, governing residential tank-style water heaters, which permit outlet temperatures to be up to 30°F higher than the thermostat's setting. Why? Thermal stacking (layers of successfully hotter water - like pancakes) occurs in all storage vessels.
The faucets have all been changed to ASSE 1016 TP (temperature and pressure reactive) valves, and the scalding problem is a not-to-distant memory. However, roughly 50% of bathing module faucets in the U.S. is unprotected two-handle models. That, of course, spells opportunity for plumbers to sell ASSE 1016 scald-guard faucets.
What does this have to do with WaterSense and plumbers? Liability insurance bites a huge chunk out of our collective butts each and every year.
In order to comply with WaterSense and garner that coveted label, showers must see a 20% reduction in GPM flow rates. ASSE 1016 scald-guard faucets are tested at 2.5 GPM at 80 psi and must stay within 3.6°F of the adjusted bathing temperature to pass muster. That 20% reduction lowers the output to 2 GPM. The majority of ASSE 1016 scald-guard bathing module faucets are, let's be honest, P-only, meaning they are blind to temperature fluctuations and react only to pressure imbalances. And, if we're really going to be brutally honest, we'll admit that most ASSE 1016 P-only scald-guard faucets are never properly adjusted for a maximum outlet temperature. But, let's ignore reality for a moment and agree that every single P-only valve will be adjusted for a maximum of, let's say, 120°F — the recommended setting.
At 120°F a healthy adult can receive third-degree scald burns after 10 minutes of exposure. Cut that to two minutes and 30 seconds for infants and elderly folks whose skin in much thinner. Still, that sounds like enough time to react — unless you're one of millions who have poor circulation or an illness that dulls your sensitivity to hot/cold. So, 120°F is safer, but not safe.
Strike 1: After adjusting for a maximum of 120°F, can you rest assured that your P-only valve will provide protection? What time of year was that adjustment made? Incoming cold water temperatures fluctuate (municipal systems) by as much as 45°F, which causes that “fixed” 120°F setting to rise/fall, so while it might be fixed at 120°F-limit today, it cannot see temperature changes. As your cold-water temperature fluctuates, so does your final mixed delivery temperature.
Strike 2: Thermal stacking will occur. The water heater was set for 120°F by the factory. You've adjusted the ASSE 1016 P-only faucet for 120°F maximum. Thermal stacking has filled the upper portion of the tank with 150°F water. At 150°F, the same healthy adult can receive a third-degree scald burn in just two seconds. It only takes half of a second of contact time for an infant or elderly person to receive a deep-tissue third-degree scalding. Got insurance?
Strike 3: WaterSense faucets are operating below the 2.5 GPM testing level and might not be able to react fast enough to stay within that 3.6°F boundary. The bigger danger, however, is adding a WaterSense shower head to an unprotected faucet and, across this great land, well-intentioned folks are giving away WaterSense compliant shower heads. No big deal, right? Let's go back to my own personal scalding experience and add a WaterSense shower head onto that non-protected faucet. My reaction to resolution took four to six seconds. The new flow-restrictive shower-head will increase the delay from adjustment to delivery.
Apply common sense
What to do? Inject just a bit of common sense and hitch it to WaterSense. We've concentrated on resolving the scalding issues at the point-of-use in the bathing module, and we know that P-only valves do not fully protect the bather.
We should fix the problem by adding an ASSE-1016 or 1016/1017 thermostatic (T-only) scald-guard mixing valve at the water heater's outlet, stop giving away free WaterSense shower heads, which have a 50/50 chance of putting folks in the cross-hairs for scalding, or give those give-aways to professionals who wouldn't install them unless scald-protection via an ASSE-certified faucet or mixing valve is added for protection.
Dave Yates owns F.W. Behler, a contracting company in York, Pa. He can be reached at 717/843-4920 or by e-mail at [email protected].
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