I have a water circulation pump which is useful for getting hot water to the showers without wasting water. However, I am undoubtedly running up my natural gas bill in the process by running the pump too long. Is there an inexpensive way to set up smart home tools to run the pump on a short timer?

What I have in mind is something like telling Amazon Alexa: "Please start the pump." Alexa will understand that the pump is only to be run for 10 minutes, so I never need to worry about checking the pump after giving the command.

  • Do you want the pump to stay on if your internet service is interrupted after Alexa starts the pump? For that matter, do you want the internet to be able to control your pump at all? Have you noticed the security track record of various online services in recent times? Oct 15, 2017 at 0:11
  • in the winter, that waste heat just becomes heat, so no loss...
    – dandavis
    Oct 15, 2017 at 13:45

2 Answers 2


I have a return water circulation pump installed on my hot water lines and I use a timer to turn the pump on during the day and off at night. The pump I used is the smallest B&G pump I could buy. It is a model NBF-8S/LW--103257LF that uses only 39 watts of power. Very little electricity is used by the pimp and very little extra nat gas is consumed when the pump is running. I had a short wire with a plug installed on the pump and I plug it into a cheap manual timer that I set to come on at 6am and shut off at 10pm. I plug the timer into a receptacle and plug the pump into the timer. This has worked for me for 20+ years. By the way you only need a very small pump, that is stainless steel or bronze since iron pumps get ruined by domestic water. As far as using Alexa, that is okay if you can remember to ask it each time. However you can't beat the cheap timer price.

  • Although the pump is drawing only 39 watts, it's the cost of natural gas to keep the recirc water at temperature that will be the issue. Wrapping the recirculation line with insulation will help reduce natural gas bill but the longer the recirculation pump is running, the greater expense! However, I'm assuming that you actually have the timer set for shutting off pump at 10am not 10pm. Recirculation pump should only be running during hours of peak use, not all day!
    – Grant
    Oct 15, 2017 at 18:10
  • Actually, I cycle the pump 15 minutes on each hour and totally off from 10PM to 6AM. Since the water line is insulated and it is in the basement ceiling, only a small amount of nat gas is used to keep the water hot at the faucets. " a small price to pay"
    – d.george
    Oct 17, 2017 at 12:00
  • I have used intermatic 24 hour timers with additional on off lugs but they make programmable models now that have battery backup so if there is a power outage you don't have to reset the clock.+
    – Ed Beal
    Feb 2, 2018 at 17:41

You an a smart plug like tplink and set your timer with an app like alexa or tplink for scheduled use or just ask alexa to turn on the pump. Only negative would be turning it off, perhaps a motion sensor to trigger the smart plug on and off in your bathroom.

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