Best way to automate hot water recirculating pump

My hot water recirculating pump is attached to a z-wave outlet ...what is the best way to create an automation that turns on the pump for 8 minutes at a time every hour during waking hours?

Iโ€™m sure it can be done other ways but here is one.


I'm New to the rule machine, how did you set up the "Select Actions to Run" part of the rule? thanks

I automate mine a little bit differently. I have one rule that turns on the water recirculation when I turn on the shower light this way while I'm getting ready for the shower the hot water is arriving

I then have another setup so I can just tell alexa to turn on hot water. This way we get hot water when we need it for washing dishes or laundry

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I use motion sensors to make my circulating pump run. It has its own temperature sensor to know when the return pipe reaches a certain temperature, so it turns itself off after at most 3 minutes or so. But to turn it on, whenever motion is detected in the kitchen, laundry room, or bathrooms, that starts the pump. This seems to work out pretty well. Every now and then I will encounter a wait for hot water in a distant bathroom, if no one has been in the kitchen for a while. But usually this approach is good.



I use the same approach, but it is restricted to the hours when I'll be using hot water. Also, my cats trigger some of my motion sensors, and I don't want the circulating pump to run during the day when my home is in "Away" mode.


First create a condition between two times.

Then create a conditional Action โ€œIf Expression thenโ€.

Then expression.

Thanks, that works. Is there a link you can share to detailed instructions for rule machine? The link in the app takes me to a video, but it seems to be an older version from three years ago


Have you seen this?

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We do it similar to @bravenel, @toy4rick, and @aaiyar with a couple additions

  1. The pump goes on when either of us get out of bed in the morning (shower coming)
  2. When the dishwasher first is powered on
  3. When we asked Alexa for hot water
  4. Maybe most important of all (we live in Chicago): when there is a bitter cold snap we allow the pump to run for an extended period to prevent frozen pipes.


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I repurposed a Hue motion sensor to the master bathroom to turn on the recirculation pump for five minutes when motion is detected. I've tried various on/off schedules none of which were satisfactory. Then tried 24/7 but hubigraphs says the hot water heater runs almost every 3 hours as opposed to 6 when the pump isn't running. The kitchen and laundry are actually very close to the hot water heater so delivery there isn't much of an issue. The master bath is why I installed the recirc in the first place and that water passes the distribution to the kitchen and laundry. Seems to be working and I can't believe it didn't occur to me to try this a year and a half ago.
--Two weeks later. What i finally settled on is constant run during the day, 6am to 10pm, and on for five minutes when motion is detected at night.

Wow - constant run during the day seems like it would use huge amounts of energy. What is being used during the day that need HW and is there a way to automate that? ie

  • for bathroom sinks, motion sensor in bath or position switch on door
  • for kitchen sinks, motion sensor or foot pedal switch
  • for dw & washer, power monitor and switch on when they go on, or motion sensor, or position switch on doors

We also don't want our pump running unless we're using the water, and our schedules/behaviors are not consistent enough to have a "get up = shower/need for hot water" automation. We primarily use the pump for hot water in the primary bathroon, which is at the far end of the house from the water heater.

We have three simple options to start it:

  1. OK Google, turn on the hot water (if you're in the family room/far end of the house from the bathroom)
  2. Press a button on picos we each have on the night stands next to our bed
  3. Double-press light switch just outside bathroom

To confirm the pump has been turned on the automation also turns on the light in the bathroom.

A follow-up automation turns off the pump after 10 minutes, which is more than long enough to ensure hot water is available at the far end of the house.

The pump uses 6.5 watts so that is insignificant. Gas water heater is the only energy issue. Compared to our last home, a large 150+ yr old farm house, we don't use nearly as much. There is a motion sensor in the master bath. With the pump off the hot water can't get to the kitchen sink and dishwasher any faster than with a cold start of the pump. I am going to repurpose another motion sensor to see how well turn on from kitchen motion works.

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Here is where I ended up. The recirc pump turns on with motion from the master bath or the kitchen for five minutes. I have a temperature sensor taped to the return pipe near the water heater that I have been using for at least a year to graph the recirc water temp. It is measuring the surface temp of the pipe buffered by a couple of folds of a 3x5 card to keep it from getting too hot. The relative temp is very consistent. There is a required expression that the temp must be below 90 deg and mode is everything but away. I'm happy with the result. The water heater seems to run for about 7 minutes to get to its shut off temperature. Previously when the recirc pump was running 24/7 it would run for about 30 minutes to fully recover and that was typically at about 3 hour intervals during the day and four at night. It runs more often now but for much briefer periods.

Upper blue line is water heater on/off, peak is on, bottom is off. Green is the recirc temp and bottom blue it the recirc on for five minute cycles.

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