What pump for home hot water recirculation?

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Tony14

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I'm running a dedicated recirculation line for our kitchen sink, which is about a 50 foot run from the hot water tank. I'm looking for a small pump, around 2 gpm, to keep the fps low and avoid damage to the pipes.

I want to use my own timer to turn off the pump during sleep hours, and a Johnson/ Penn A421ABC-02C aquastat so I can control the turn-on and turn-off temperatures.

The Grundfos Comfort pump models 99412493, 99812354 and 98420224 are the right size, but they have temperature, timer or auto feature respectively which do not meet my needs.

This would be okay if I could be sure whatever feature is on the pump I buy can be turned off and stay off. But in reading the little I can find about these pumps it seems that while you can turn off whatever feature the pump has, when the pump loses/regains power it reverts back to having the feature turned on, with default values (e.g. for the timer pump 6:00am-9:00am, 11:00am-1:00pm and 4:00pm-9:00pm).

Can anyone with knowledge of these pumps tell me if their features can be turned off and stay off across power outages?

If not, does Grundfos have a low-flow pump like the ones in the Comfort line but which has no such features, so that it can be turned on and off externally without complications?

If not, can anyone recommend another brand of pump of comparable power and reliability without any fancy and in my case unwanted features?

Grundfos does not talk to homeowners. They referred me to a supplier in my area but the contact there recommended a more powerful pump that I believe would move the water too fast. So did two local plumbing stores. I guess I could use a larger pump and add a flow restrictor, but that's just solving a problem I shouldn't have in the first place and adds something else that can go wrong over time.
 

John Gayewski

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Taco 003 should give you about 3.5 gpm at 3ft of head.

The pump could be a bit oversized, but it's the smallest pump of high quality. Grundfos makes some junk.
 

Reach4

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How about using a button to turn on the pump for a bit when you are about ready to use hot water? Very power-efficient, and no concern about eroding pipes.
 

Tony14

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So, would a, say, 2 gpm flow restrictor work? Does it put stress on the pump, which is trying to push more water through? Are flow restrictors reliable in the long term?

I have considered a button but we decided on external timer and aquastat.
 

Reach4

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A 2 bpm flow restrictor would hot put stress on a centrifugal pump, and I would presume the proposed pumps are centrifugal pumps.
 

Tony14

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Oh that's good. Cause not having any luck finding a ~2 gpm pump.

John, I looked for Taco 003 pumps and found many models. Is there any particular one I should consider?
 

John Gayewski

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Oh that's good. Cause not having any luck finding a ~2 gpm pump.

John, I looked for Taco 003 pumps and found many models. Is there any particular one I should consider?
An ecm model that is bronze or stainless.

Any balancing valve to restrict the flow should be on the outgoing side of the pump piping, not in the intake side.
 

Tony14

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Balancing valve? Only recirculating to one destination, the kitchen sink. Does a balancing valve work in that situation?
 

Tony14

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I found a YouTube video, "Sizing Domestic Hot Water Recirculation Pumps" that really helped me put all the pieces together. After going through a manual process it shows an app on the Taco website that lets you describe your system with a few entries then makes pump recommendations--Taco pumps, of course, but they may have earned my business. Very helpful.
 
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