Many people might take it for granted that when they turn on their water everything will flow normally. But some homes might be missing an important piece of equipment you may never have heard of -- pressure regulating valve.
Margaret Cantrell learned the hard way. She has an expensive mess on her hands.
One morning she found her patio flooded after the top of her water heater had blown apart.
"It was like a fire hydrant," she said.
Metro Water Services came out and tested her water pressure. It was 100 pounds per square inch (psi) when it should have been less than 80 psi as the water entered the house.
That's when Cantrell learned she should have had something called a pressure regulating valve. Most new houses have them, but her house isn't new.
"Not knowing, and that's what I'm frustrated about. I didn't know, and I think a lot of people don't know," she said.
Jeff Siedentop with Hiller Plumbing, Heating and Cooling said most homes have a pressure regulating valve. But when one is missing it can damage to faucets and cause water hoses on washing machines to blow.
"What it does, it controls the pressure inside your house. The main pressure outside - the street pressure - is usually higher to get enough water to everybody's house," he said.
If you have a pressure regulating valve it could be in your garage or crawlspace.
"It will be on your main water line. It should be right behind your main water shutoff," said Siedentop.
The Metro Water Department said they have to maintain sufficient pressure to fight fires, and so people have decent showers. Water pressure can fluctuate for a variety of reasons, such as a water main break or a pumping station malfunction.
Metro adopted a rule in 2006 saying if changes in water pressure damage a customer's house, the customer is responsible for the damages.
Cantrell wishes they'd sent out a notice with her water bill. Replacing the water heater and cleaning up the damage will cost her about $1,000.
Siedentop said that pressure regulating valves can wear out over time and need to be replaced. One sign they are failing, he said, is if the water sprays out hard when you turn the faucet on, then slows down.
