How many bypass valves do I need for a Grundfos hot water recirculating system?

Asked by Bob
Plano, TX

I am considering purchasing and installing the Grundfos hot water recirculating system. I have a two-story house with a 50 gal water heater located in the basement. There are two bathrooms on the upper story, and a kitchen and bathroom on the main level. Do I need to install bypass valves in all four locations or just the bathrooms on the upper floor?


Rob Smith, LEED AP H

Answered by Rob Smith, LEED AP H

Winter Park, FL

e2 Homes

January 20, 2011

I would say that the answer to your question depends on how your plumbing trunk lines were run, but..

  • it should be as simple as installing the valve at the furthest location from the water heater. 
  • This way, hot water will run through the trunk lines anytime the pump is activated -- running past each of the closer locations and resulting in short wait times for hot water anywhere. 
  • You will also not waste any water during the wait.

I recently installed this type of pump as part of a green remodel/addition to a one-story home in Winter Park, FL.

We created a split plan, by adding a master suite to the far side of the home (furthest from the existing baths). This resulted in a long wait time for hot water and the hot water recirculating pump resolved the issue.

I hope this helps.


For more information:

Read Ray Pruban's Q&A "I am considering a water recirculation system for a second home, but for the next 10 years I'll be there only once/mo. Should I bother?"

Tagged In: hot water recirculating

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