Expansion tank with no pressure regulator?

Many are set up that way with a bladder tank Fill valve is probably sufficient to act as backflow prevention.

idn't have a water pressure regulator but he had an expansion tank above hi s water heater. He said the guy who installed the water heater told him he needed the expansion tank to meet code. I doubt there are any backflow prev ention valves unless it is built into the water meter outside.

The expansion tank is to prevent water hammer, has nothing to do with press ure - that is provided by the water system. The back flow preventer would be part of the water meter.

Harry K

and noticed that he didn't have a water pressure regulator but he had an expansion tank above his water heater. He said the guy who installed the water heater told him he needed the expansion tank to meet code. I doubt there are any backflow prevention valves unless it is built into the water meter outside.

Did you have a question, or are you just thinking out loud?

. Christopher A. Young Learn about Jesus

You mean the water authority here has been lying to me?

My question would be whether such a system makes sense? Unless there is a backflow preventer out in the outdoor water-meter the expansion tank isn't going to do much of anything.

Unless there is a backflow preventer out in the outdoor water-meter the expansion tank isn't going to do much of anything.

Agree. Your thought makes sense, to me.

. Christopher A. Young Learn about Jesus

Above a domestic water heater, you are correct unless there is a check valve. My original thinking was a boiler (often used as a water heater also) where the fill valve would act as a check valve too. There it makes sense.

Sometimes there is a check valve at the water meter to prevent back flow that could contaminate the public water supply. When the water in the water heater expands from being heated, it will leak out of the TP valve on the heater if there is no expansion tank. It really depends on the practices of the utility supplying water in your area and the plumbers will know. ^_^

TDD