This Old Plumbing
It was a typical Saturday morning in the dead of winter. I was finishing up a project in the house, grouting the new tile in my son’s bathroom. My wife came running down the stairs, yelling my way. I wasn’t sure if she was in a state of panic, or a state of excitement. When you’re married nearly 20 years, panic and excitement seem to run together.
When Judie reached me, she exclaimed, “You just missed it. That plumber on This Old House just blew it. He was telling everybody that they need to put in air chambers to prevent water hammer. I can’t believe he would tell them such a thing.”
The door to the bathroom was closed since I was grouting behind it. Speaking through the door, I responded with, “Richard told everyone to install air chambers?”
“You know him?” she asked.
“No, not personally, but every plumber knows of Richard Trethewey. He’s been the plumber on This Old House since the days of Bob Vila.”
“Well,” Judie commented, “you better straighten him out. After all of the work you have done, how can he still be recommending air chambers?”
Since Judie and I work together, she has heard me spout off many times about the stupidity of air chambers. Since she is my sounding board, she assumes that by now every plumber in the world knows that air chambers don’t work. But, to correct this injustice, I thought I would send an open letter to Richard Trethewey:
Dear Richard: Let me start by saying that my family loves This Old House. We have been watching for many years. When my son was growing up, Bob Vila was his hero.
Every time you would appear on the screen, my family would hoop and holler, looking at me. They wanted to see what I would say about a fellow plumber on the television. Of course, I would just watch and enjoy the show.
I like the fact that you have introduced the public to the wonders of hydronic heating, especially radiant heat. I grew up in a house with radiant heat and didn’t own a pair of slippers until I went to college. The floor was always nice and warm. The heat was the best you could have.
You have also introduced the public to many new and innovative things in the plumbing and heating industry. You’ve never shied away from discussing the advances made in the plumbing and heating profession.
This past week, however, you really bothered my wife. She saw you recommending the installation of air chambers on the water piping with every fixture to prevent water hammer. My wife is not a plumber, yet she knows that air chambers don’t work. Richard, how could you recommend such an installation? Even if the Massachusetts Plumbing Code requires air chambers, that doesn’t mean they’ll do anything. That just means the code is wrong. The funny thing is, most plumbing codes are wrong when it comes to solving water hammer problems.
As a responsible member of the television media, you should be educating the public on the proper ways to solve water hammer problems, which is the use of water hammer arrestors. You have one of the manufacturers, Watts, just up the road from you. I’m sure they would help you with educational information. Or maybe you should contact Sioux Chief. They had a neat demonstration at a plumbing show whereby they measured the intensity of the shock wave with and without water hammer arrestors. They even installed an air chamber and showed how it worked all of four times before water hammer reappeared. That is all it took to fill the air chamber enough so that it was totally ineffective. I am sure Sioux Chief would appear on television with their water hammer demonstration display.
You don’t have to just consider these two manufacturers, there are other manufacturers as well. They all make fine products that prevent water hammer.
I have written a number of papers on this subject. One thing that has been clearly established is neither PEX nor CPVC has a water hammer problem. If you are piping with either of these materials, you don’t need water hammer arrestors. When using copper, you only need protection when there is either a higher pressure or the flow rate is excessive.
If a flow restrictor is in a lavatory, and the flow is limited to 2.2 gpm, water hammer arrestors are only necessary if the pressure exceeds 60 psi. For a showerhead, a pressure above 45 psi would need water hammer arrestors. But if you put the arrestors in for the lavatory, they will also work for the shower and any fixture within 20 feet of the arrestors.
Please don’t tell the public about these falsehoods of air chambers. If they are gullible enough to believe air chambers work, and they find out they really don’t, it could destroy all of your credibility. I have too much respect for you in presenting the positive side of our industry.
While I’m at it, there is one other thing that has always bothered me when I catch your show. Every time you set a water closet, you tighten the bolts and say, “That’s all it takes,” or something to that effect. You never show the grouting or caulking of the water closet base to the floor. This is a very important part of a water closet installation. Especially if there are little boys in the family who miss the bowl every so often. You can’t clean under the space, which is the reason we grout around the fixtures when they come in direct contact with the floor or wall.
Otherwise, I love the show. Keep up the good work.