Hot water circulating pump issue


  #1  
Old 06-19-24, 06:30 AM
J
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Hot water circulating pump issue

We have been our new home several months. Here is the issue we are having with hot water circulating pump:

If the recirculating pump is plugged in (on), the cold water starts out very hot and need to run for several minutes to get cold. If the recirculating pump is unplugged (off) with valve at recirculating pump closed, the cold water is cold from start, but the hot water does not get fully hot. If the recirculating pump valve is closed, the water is hot but without recirculating pump on, takes several minutes for hot water to reach faucets. I confirmed the circulating pump was installed in correct direction (i.e., arrow pointed toward hot water heater).

Could there be a faulty or missing check valve allowing the cold water and hot water lines to mix?

Thanks in advance for your help.
 
  #2  
Old 06-19-24, 01:22 PM
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We need to know what type of system you are running..... specifically.

The cold water should remain cold.
Do you have a separate return line to the water heater/pump ?

The pump is supposed to pump water from the hot water line back to the tank.
OR... the pump.. pumps water from the hot water line into the cold line until the hot water line is hot.
 
  #3  
Old 06-19-24, 02:55 PM
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Do you have many single-handle faucets? My understanding (probably limited) is that when the handles are left in a middle position, hot and cold can mix, thanks to the recirculating pump. Try making sure your single-handle faucets are left at Cold when not in use.
 
  #4  
Old 06-19-24, 03:53 PM
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They don't mix if they're off.
 
  #5  
Old 06-20-24, 04:58 AM
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Thanks to all for your input. Took quite a bit of time, but tracked it down to a faulty shower mixing valve. Even though the water was not dripping from the shower head, the handles needed to be firmly closed to stop the problem, I will be changing the cartridges today. The hot water was mixing in with the cold water and the recirculating pump was sending it back through the system.

Hope this helps anyone else with same issue.
 
 

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