Just moved into a new house, and the the previous owners had the hot water re-circulation pump running continuously.

I programmed the analog timer on the pump to provide hot water for peak usage times, but I was unsatisfied with not having hot water when I wanted at random times during the day.

Put the recirculator pump on a TP-Link smart outlet switch ($20?) that I already had lying around (was using it for a lamp). With the smart switch's built in app, I have much more granular control over the schedule (different schedules for weekends and weekdays).

Better still, the app is connected to Google Assistant and Alexa. I just say "Hey Google, turn on the hot water," a few minutes before I need it. Alexa's integration is a little better, as I have it set to turn on for a set number of minutes and then turn back off again (the amount of time it takes the water to reach the furthest bathroom, about 15 minutes).

Small wins for these quarantine times.

Google and Alexa? No thank you. Mine is on a time clock. Good enough.

quote:

Originally posted by PowerSurge:
Google and Alexa? No thank you. Mine is on a time clock. Good enough.

Google and Alexa is optional.

You can use the smart switch's app (whichever brand you might choose), and just create a button for it on your smart phone.

I've seen new construction houses with recirculator remotes wired in near the master bath or the kitchen sink. Mostly for tankless water heaters. This serves the same purpose, just substantially cheaper.

I thought it was pretty clever.

quote:

Originally posted by PowerSurge:
Google and Alexa? No thank you. Mine is on a time clock. Good enough.

Come on man, with IOT and 5G you can assure someone is always watching you. Big Gov/Tech are our benevolent dictators caretakers. You can trust them.

Don't have a recirculation for my on demand water heater.

however maybe need to look into that, wonder if they have an app and switch for the On Demand, that would be great to be able to turn on the HW in advance of need by voice.

I see you can add motion detectors that turn on the pump when you enter a room. Sounds like a good solution but it may not give enough time to use.

I have two water heaters, one under the house that is pretty old, a lowboy style, and it's installation is not to code anymore, plus the new models will not even fit through the access door due to more insulation, bigger size. One was in the laundry room. I moved the entire laundry to the garage to eliminate damage from the eventual leaks and to repurpose the space to a pantry.

When the underfloor heater goes I plan to re-plumb the entire house to the water heater in the garage, up size it and add a recirculation pump so I have been casually looking into them.

Question...
The pumps use very little electricity, so the savings in turning them off is saving heat loss from the pipes. If the pipes are very well insulated how much savings can one expect by cycling the pump off and on as needed vs on 100%?

Also some have an in line thermostat to cycle the pump on and off, another option.

quote:

Originally posted by HRK:
Don't have a recirculation for my on demand water heater.

however maybe need to look into that, wonder if they have an app and switch for the On Demand, that would be great to be able to turn on the HW in advance of need by voice.

I've seen new construction with tankless on-demand water heaters with buttons near the sinks and showers that will trigger the heater and recirculate the hot water. So, that application definitely exists. Might need to dig a little to figure out how to make a series of smart devices work for something like that.

quote:

Originally posted by cparktd:


Question...
The pumps use very little electricity, so the savings in turning them off is saving heat loss from the pipes. If the pipes are very well insulated how much savings can one expect by cycling the pump off and on as needed vs on 100%?

Also some have an in line thermostat to cycle the pump on and off, another option.

Yeah, the pumps use very little electricity. Also, it probably depends on your tolerance for waste. With regards to pipe and pipe insulation efficiency, I'm sure much of that equation will have to depend on the size of your house, the external temperatures you are dealing with, and the number of fixtures you have hot water running to.

I can tell you that the pipes in this house go from full hot to full cold in just a couple of hours--and that the volume of water in the pipes from the heater to the furthest bathroom takes 5+ (maybe even 10+, takes freaking forever, don't have the heart to waste the water to find out) minutes of running water to get up to shower temperature.

With interconnected smart devices, you can do a lot of customization. For instance, you might be able to program the hot water to recirculate after you've turned on the coffee maker. You can probably set it to run at different schedules based on thermostat temperatures. Maybe even have it set to run only when your phone is geolocated within your home, or when you leave work. Many of these things will require tweaking and tinkering with things like If This Than That, but the solutions are out there.

My current recirc pump is built for on-demand only.
Each sink has a door bell style button in the cabinet.

Can still take a bit of time to get to the fixture.

It only runs on button transition.
I added an Arduino board tied to an extra relay on my furnace thermostat that tells it to push the button every 5 minutes based on a schedule in the thermostat.

I have a new zwave controlled relay system that I plan on moving it to. This will let me have it run on a schedule too but also based on home automation activities (motion sensors, lights being turned on, ...), Will also allow me to not have it run when the house is unoccupied.