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Pressure Reduction Valves: How Spending $85 Can Save You Thousands

Sept. 21, 2012
Personal Finance
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I just dodged a bullet. Or maybe I should say a deluge. I live on a quiet street, in a sweet little house built in 1921. It’s been added onto at various times, and the previous owners have taken pretty good care of it. Recently I noticed a pool of water under my water heater. Since it’s in the basement on a concrete slab, no harm was done, but once I had the estimate from my plumber, I learned that although the water heater was the biggest expense involved, it wasn’t the only one. Here’s what I learned.

Apparently, any plumber worth his salt will check the pressure on the water service to a house before installing a new water heater, since the tank is not guaranteed if it’s subjected to pressures over 80 pounds per square inch (psi). Interestingly enough, the water company has recently been replacing old, leaking water lines in our area and tightening up the system – but as far as I know my water pressure has never been measured at all. My plumber checked it, and it turns out that my plumbing has been dealing with at least 150 psi since I bought the place several years ago. The flow in the shower was amazing – I’m sorry to lose it – but what about that water heater sitting in my basement with the tank slowly rusting away? What about the rest of the system?

Before he connected the new water heater, the plumber installed a new pressure-reduction valve ($85) where the water from the street enters the house. That helped preserve my plumbing. He also tucked a little expansion tank ($36) into the floor joists above the water heater. This deals with a problem that didn’t exist when my house was built: what to do with the increased volume of the newly heated water? In the old days its pressure would just push some water back into the city’s pipes, but that’s not allowed anymore for sanitary reasons. Now the expansion tank accepts the extra water and feeds it back to me when someone turns on the hot water.

Quite fascinating, right? Next I’ll talk about how I fixed my lawn mower. But wait!

A few days later a neighbor just up the street happened to tell me that a pipe in her bathroom had burst a few months ago, and filled her house with several hours’ worth of water when she was away. As a result she was out of her home, living with neighbors, for months on end while her water-soaked possessions were hauled away and the interior of her home was rebuilt – and of course she lost many things that can never be replaced. During the renovations someone suggested that she have a pressure-reduction valve installed while the workmen were there, but her contractor (a builder, not a plumber) had never heard of those gizmos, so the idea was set aside.

The pipe that burst? As a matter of fact, it wasn’t a pipe at all – it was a flexible rubber water line, sheathed in stainless-steel mesh, of the type used in most bathrooms to connect the toilet to a cold-water pipe. It’s still there as I write, very likely handling the same water pressure that my house does – plus the odd pressure surge. Yes, I’ve advised my neighbor to have someone (a plumber, or even the local water department) check her water pressure – and now you know why that might be a good idea too. But there’s that $85 to think about. Plus installation.