Grab the (scalding) bull by the horns, part 2

THE PLUMBER Protects the Health of the Nation. Strong words and a credo willingly accepted by those of us who choose to work in this honorable profession. Prior to modern sanitary plumbing, water-borne diseases were the leading causes of death for centuries. In fact, contaminated drinking water was the single greatest cause of human disease and death.

Typhoid fever, cholera and dysentery were the bearers of death in the early part of the 19th century. The collective efforts of plumbing code officials, plumbing engineers, designers and installers have saved more lives in the past 100 years than all the medical professions combined.

Remember from last month’s chart (pg. 32) that young children will receive a second-degree burn from 120°F water in 1.2 minutes and a third-degree burn in 3.1 minutes. (The times are longer for healthy adults). It’s easy to see that we have not eliminated danger in the use of potable hot water.

Third-degree burns require skin grafts. Skin grafts do not grow as the child grows, which means they must return for additional surgery until fully grown. That’s a childhood filled with misery and a lifetime of disability.

If we try to extend the scald injury times from minutes to hours by reducing potable hot water temperatures at the source and within the distribution system, then bacterial disease issues loom larger.

Suppose I were to suggest that there is a very simple way to remedy not only the scalding issues, but to kick bugs like Legionella in the pants while, at the same time, reducing liability for everyone involved. Hard to believe, isn’t it? The lawyers won’t like it one bit.

Let’s use any potable hot water vessel you like, be it a standard gas, oil or electric model water heater or an indirect storage tank. Let’s raise the storage temperature to 135°F or 140°F. Now we’ve got much hotter water with contact temperatures ensuring pasteurization of the water for suppressing Legionella population numbers.

Dangerous hot water temperatures exist now and with the potential for stacking to occur, scalding times are shortened. We’ll need to address this next and that’s easy to do by adding a listed ASSE 1017 thermostatic mixing valve in the outlet piping.

It’s important to note two things: These are not rated as anti-scald devices, and, second, it must be a “listed” device and not one simply claiming it conforms to the ASSE listing.

Now that we’ve flat-lined the source outlet temperature with a listed ASSE 1017 device, let’s add constant circulation to prevent stagnation and maintain the elevated 135°F to 140°F water temperatures. I’d like to see a temperature gauge here, wouldn’t you? That would make our job setting up the 1017 device delivery temperature a snap. All along the potable hot water highway, there would be road signs stating, “No Bugs Allowed!”

Last, but certainly not least, we need to protect the public using this 135°F to 140°F potable hot water at each point of use. Here’s where the listed ASSE 1016 anti-scald point-of-use devices come into play.

Remember the three types of anti-scald valves: P, T, and P/T or good, better and best? You might think the P (pressure balancing) types are worry-free now that we’ve flat-lined the point of source outlet temperatures, but we need to remember they’re blind to temperature changes and municipal potable water systems often see a wide range of delivery temperatures as the seasons change.

OK, we’ve shifted liability from the water heater manufacturers to the manufacturers of the ASSE 1017 and 1016 devices, but we’re still in the cross hairs of liability suit marksmen and that too can be addressed.

Suppose it was the responsibility of the plumbing inspector to check the point-of-source temperature at the thermometer we’ve installed just downstream of our listed ASSE 1017 device; verify constant circulation throughout the potable hot water distribution line(s); check every point-of-use device where a potential for scalding exists to verify a listed ASSE 1016 device is in place; perform a running water temperature check to ensure delivery temperatures are within a safe range; fill out an inspection report; and have the homeowner sign off acknowledging the inspection was performed.

Wouldn’t that be grand? Scalding cases would be greatly diminished and bacteria such as Legionella couldn’t gain a foothold. When bidding your work, everyone would be on the same playing field and safety wouldn’t be held hostage by the competitive bidding process. But it can’t and won’t happen until the national plumbing codes address these issues. The only argument that can be presented against putting these common-sense solutions to work is the notion that it will cost the consumer too much money. The fact is we cannot afford not to implement these changes.

Dave Yates owns F.W. Behler, a contracting company in York, Pa. He can be reached by phone at 717/843-4920 or by e-mail at [email protected].