Hi folks,

Reading this forum has helped to explain that in many cases a leaking Watts brand PRV rated at 150psi is "just a symptom." I need your help in finding the root cause for the leak.

I have 2 50 Gal Water heaters installed in Parallel in my garage(as I can turn off cold inlet on one heater, and still get hot water-turning off both inlets shuts down Hot water flow).

On one of the 2 year old tanks the Pressure Relief Valve (PRV) is leaking now, which was replaced a year ago due to similar issue. Shutting the cold inlet and throwing PRV to release several times doesn't help.

My own gauge says Water pressure is between 90-110psi range when heater is idle/fireing. Seems high to me. A year ago the city cked it and said pressure was normal, but I cannot remember the PSI then.

I'm pretty sure I have a backflow preventer at the street meter as the neighborhood is only 10 yrs old, and confirm I have no expansion tank, nor a Water Pressure regulator (unless city installed it at the street)

Since this is the 2nd PRV on with the leakage on the same 2 yr old heater, I'm thinking the root cause is excessive water pressure.

So, my questions are... In order to verify the root cause, (since the PRV is just a symptom),
1. should I have a plumber ensure there is a water pressure regulator is installed first at the street, and verify "normal" pressure at about 70psi, before I walk down the Thermal expansion tank route inside the house?

2. OR Should I install a expans tank, and a new PRV.. or do #1 and #2-seems extreme.

2a. If you think I should install a expansion tank, should I install 2 of them, one per water heater inlet or just a single exp tank on one of the heaters inlet?

Thanks in advance,

Steel

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I'm pretty sure I have a backflow preventer at the street meter as the neighborhood is only 10 yrs old, and confirm I have no expansion tank,

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If you have a backflow preventer installed and no expansion tank installed to cushion the pressure spike then you have found your problem. Iinstall a expension tank and watch your leak go bye-bye.
Good luck, Tom

Do you think a Pressure regulator is needed in addition to the Expansion tank?

Should I get one or two expansion tanks for 2 50 gal heaters?

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Originally Posted by ;

My own gauge says Water pressure is between 90-110psi range

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The average house pressure runs about 45 PSwith a top PSI of 80.
I would first install the PRV, and it installs inside your house where the service enters. It's the backflow preventer that installs next to the meter.

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Should I get one or two expansion tanks for 2 50 gal heaters?

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When you r pressure spikes it affects the system. One tank on a cold water feed should do very nicely but bringing down the house PSI with a PRV may just solve that problem. Install the PRV first and watch the T & P valve. If it still leaks then install the expansion tank. Good luck, Tom

OK, I will be replacing the Pressure Reducing Valve first... since I found I have no valve between me and the street.

Is there a difference in quality with PRVs? I'm looking at the Honeywell cartridge type, Honeywell DS05G1085 PRV for about $100, which has a plastic bonnet. Would a plain old cast WATTS be better or same?

Thanks,

Steel

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