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expansion tank location with tankless heater

Brain Ross
Member Posts: 20
I'm installing a noritz tankless dv hot water heater with noritz's hot and cold isolation/pruge valves. Since the valves attach to the tankless with half unions there is no place between the cold valve set-up and the tankless to cut in an expansion tank.
Should I then install the expansion tank between the prv and the iso/purge valve set-up. I have always been under the belief that the expansion tank should be installed before the cold water shut-off incase the valve is closed it would still absorb any expansion without activating the prv.
Should I then install the expansion tank between the prv and the iso/purge valve set-up. I have always been under the belief that the expansion tank should be installed before the cold water shut-off incase the valve is closed it would still absorb any expansion without activating the prv.
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Comments
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I wouldn't put one in....
It's a tankless, which means it won't be firing unless a tap is open. Expansion tanks are there to allow the expansion to be absorbed. You won't have any expansion to speak of, because if the burner is on, a tap is open. When the tap is closed, the burner is off.
Save your money for something else.
METhere was an error rendering this rich post.
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