Don’t try to play games with the federal restriction on maximum flow rates.

I was asked to inspect a plumbing rough-in installed in a beautiful new home on the shores of Lake Michigan. The home was gorgeous, but the plumbing, well let’s just not go there.

As I hit the main floor, I was immediately drawn to the shower. There were two shower valves roughed-in for the shower. It wasn’t a large shower, so I asked, “I noticed the two shower valves, is there a reason for that?” The woman who owned the house smiled and responded, “For fun!”

I’ll have to admit, I appreciated the honest answer, even if I did start to turn a little red in the face. Since I opened the subject matter, she started to pursue some questions regarding the shower valves. She said the replacement plumbing contractor recommended installing only one shower valve with two showerheads. I immediately responded that as far as I was concerned the double showerhead was illegal.

She was happy to hear that since she had a good reason to tell the contractor to leave the two valves alone. She went on to explain that she prefers to allow each person to control their own water temperature and flow pattern, even if they are having fun. Without individual control, she concluded that it would not be as much fun to be in there together. It certainly was an interesting conversation.

Breaking The Law

Of course, the new plumbing contractor, as well as many of you, have installed the double showerhead. I don’t need to name the manufacturers, you all know who makes them. What is extremely disappointing is that many plumbing inspectors have permitted these double showerheads to be installed.

In addition to the double showerheads, many plumbing contractors are resorting to repiping certain manufacturers’ showers that are designed to recirculate the water that collects in the tub. The shower valve volume and body sprays far exceed the 2.5 gpm maximum. The recirculation of water in the tub allows the showerhead and body sprays to fall outside of federal limitations. That is, until the plumbing contractor repipes the system to be straight potable water without the recirculation feature.

How So?

You may be asking, “How can a manufacturer sell the double shower valve if it violates federal law?” My response is either they haven’t been caught or the Department of Energy doesn’t care.

The manufacturers, plumbing contractors and plumbing inspectors all are trying to play games with the wording in the federal law, which restricts the maximum flow rates from typical household plumbing fixtures. They twist the wording around and conclude that each showerhead is limited to a maximum flow rate of 2.5 gpm. Hence, by putting two showerheads together, they conclude that the total flow rate from the single fixture is 5 gpm.

I will admit that this is nifty wordsmithing, but it is also a violation of the law. Using this convoluted logic, if you place five showerheads from the same shower valve, you can have a total flow rate of 12.5 gpm. Wrong!

The law is quite specific in allowing a bather to shower with a maximum flow of 2.5 gpm. Now if the shower has two shower valves (i.e., for two people) then there can be a maximum of 5 gpm when both showers are turned on.

Look To The Book

I am always asked how I am so sure about this. Well, when in doubt, it is always good to see how the codes and standards interpret the situation. The plumbing code applies the limitation of 2.5 gpm to the shower or showerhead. In other words, you can limit the shower valve or the showerhead. However, the requirement applies to each shower valve, regardless if there are two showerheads, body sprays or whatever.

How Come?

So, why do they sell these double shower valves? Good question! When I read the federal law, it seems clear that not only can you not install a showerhead that exceeds the limit, but you cannot sell such products in the United States. When one of the catalogs was selling old-style Speakman showerheads (manufactured for other countries), the Department of Energy received a number of complaints. I noticed that the shower quickly disappeared from the catalogs. Oops, I guess they really were violating the law by selling the showerheads.

Eventually, I would expect the Department of Energy to investigate the double showerhead. Once that occurs, the showerhead will probably disappear from the marketplace.

I will probably hear from a number of corporate attorneys stating that I am wrong. They will explain how they can make the words work in their client’s favor. My response will be, “Hogwash!” You can play games with words all you want, but the bottom line is that a bather is only entitled to 2.5 gpm of water when showering. If they want two people showering together -- for fun, of course -- then install two shower valves.

There are those plumbing contractors that still tell me that 2.5 gpm is an inadequate amount of water to get a good shower. Again, “Hogwash!” I measured the quantity of water coming out of the showerhead in my bathroom. It is all of 2.2 gpm. That is plenty of water for a comfortable shower.

With all of the traveling I do, I get offended when a newer motel or hotel has removed the flow restrictors from the showerheads. There is way too much water flowing while taking a shower. I feel like I am drowning.

By the way, it is not just the water we are saving. It takes energy to heat the extra water. You also increase the amount of water that needs to be treated at the treatment plant. That takes additional energy.

So forget about the double showerhead. Be a good American citizen and follow the federal law that restricts a shower to 2.5 gpm. Your children will thank you.