Varying Hot Water Temp When Recirculating Line Is OpenI’m

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Hi everyone,(DIY Poster)

Looking for a help on a new hot water heater installation that is causing issues on a closed loop system.
History; When I purchased my house, the home inspector noted that the hot water system was not to code for two reasons.
(1) there was no check valve on the cold water inlet, to prevent back flushing hot water into the cold water line.
(2) with a closed loop system, a thermal expansion tank would be required.

Yesterday; I replaced the water heater and installed both the check valve and thermal expansion tank.
Now when the recirculating line is open different taps throughout the house have varying temperatures from ice cold, to warm, to the expected temp. As soon as the recirculating line is shut off. All taps run at the expected temperatures. The variation in temps also varies at similar run lengths and altitude.
(Not like all the close taps are hot, and far taps on 2nd story are cold.)
There is no directional recirculating pump on the system.

Details that have been verified.
Direction on check valve.
Pressure of expansion tank set 2 ps above water pressure.
No bypass connection from hot / cold water lines.

Any help or ideas would be greatly appreciated.

Secondary questions,
Should the recirculating line have a directional check valve, as the recirculating line is attached at the cold water inlet?
Should the system have recirculating pump, and not rely on thermal distribution?


Thanks again,


John Gayewski

In the Trades
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Yes the recirc line needs a check valve that dictates the water flow only back to the heater. That is the ONLY thing that keeps the recirc line a recirc line.

Your home inspector is wrong. You don't need to close your system.
Hey, wait a minute.

This is awkward, but...

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