I have a tankless hot water heater in my house that is hooked up to a "on-demand" recirculation pump. The idea being that instead of turning on the tap and letting the cold water run through and down the drain, I can activate the recirculation pump on demand, wait for the pump to do it's thing (takes 3 minutes) and then turn on the tap for "instant" hot water. Works very well but I'm still waiting 3 minutes so while I'm saving water, i'm not saving time.
The recirculation pump is activated by a wireless RF remote. On the manufacturer's website, there's also an option to replace the RF receiver with a motion sensor instead. I can't use the motion sensor because the pump lives in the garage and I need hot water throughout the house.
One idea I had was perhaps there's some sort of zigbee/zwave relay switch I can use here in place of the RF receiver that I can control via hubitat but I'm not really sure if it exists or what to look for.
The other possibility is buying a switchbot which physically presses buttons. I could use that to press the wireless remote button but seems like a real hack job and switchbot apparently requires a hub of its own . Plus the button on the remote is kind of tiny and I'm not sure the switchbot could press it or not.
I'm hoping the fine people on this board may have a solution. The recirc pump is this one for reference: TacoGenie | Instant Hot Water | www.tacocomfort.com It cannot be programmed to run on a timer or 24/7
INSTALLING THE TACO GENIE STARTER BUTTON
The manual starter button is a unique feature to the TacoGenie. Using the manual start button maximizes energy savings and controls operation only when there is a request for hot water.
Drill a 5⁄8" hole into the desired location, typically the side or front of a vanity cabinet.
Insert the gray wire from the controller through the back side of the hole and connect it to the starter button.
Firmly insert the button into the drilled hole.
Note: To operate the TacoGenie from other locations throughout the house, additional starters can be installed and spliced into the gray wire provided. Or for wireless remote operation, the Taco #554-1 transmitter/receiver kit can be easily installed.
See “WIRELESS REMOTE KIT OPTION” below for instructions.
If wireless remote kit is not installed, use electrical tape or wirenuts to isolate the three leads (black, white and green) on the black wire.
Zen 16/17 should be able to trigger the pump cycle.
It sounds like you'd need to use the normally closed contacts, trial and error might require switching one wire.
The Bond Controller is another really good option if you already have the remote control module... it's basically an IP > RF gateway (one way) that can be used to send commands from HE to any RF-controlled device. I use it for ceiling fans and fireplaces. (I do not automate fireplaces... I just use it for remote control.)
I have a similar setup. I have a Rinnai tankless with a JWATTS recirculation pump. Here's how I handled controlling the pump:
I have the recirculation pump plugged into a Zooz Zen25 double outlet.
The pump recirculates for three bathrooms.
At Hubitat, I have a rule set that if any of the bathroom lights turn on, then the pump turns on.
If ALL of the lights are off, then the pump turns off. I also have a timeout - if the pump stays on more than 15 minutes, it also turns off after that time (in case a light was left on, I don't want the pump running constantly).
Finally, for extra confidence that the pump doesn't stay running, the Zen25 also includes an "Auto-Off" parameter setting which I have set to turn the pump off after 15 minutes. Thus, even if the Hubitat failed (e.g., if I happen to reboot while the pump was on, but before Hubitat turns it off), I can still be sure the pump turns off via the Zen25 forcing it off.
This was worked great and is easy to do. I've been using this setup for about 2 years and its been trouble free. Consider something similar.
I was assuming that you could just connect the "doorbell button" switch wires or motion detected wires together so it is in an "always on" setting, then control Via ZEN25. But the other poster's suggestion of Zen16/17 sounds like it may be better for your setup.
Ah this makes sense too. This particular pump actually shuts itself off when it senses hot water coming back on the cold line. I'll have to explore, these are all great ideas.
I went pretty simple. I have my recirc pump plugged into a Zigbee outlet. I have pushbuttons in every bathroom for 1 push on and hold push for off. I also have a setting for off after 15 minutes from the on push. I also have an Alexa routine so I can voice command it to turn on, with a 1 hour turn off so that I can run it during a dishwasher cycle.
Something similar to what I do. Except it is activated by motion sensors in the shower, and only runs for 5 mins after the first time is activated within a 30 minute interval.
Why? Once hot water from the water heater is at the dishwasher, which should presumably take much less than 1 hour, there is no benefit to be gained by running the pump any longer, is there?
The reason I keep it running for an hour is that there are multiple cycles of fill, wash, or rinse with my dishwasher and this keeps the water hot. The recirc pump has a built in temp sensor that cycles the pump so it is not running continuously.
I get that. But all that happens in a relatively short time-span (1 hour). Is the heat loss from the internal piping that high?
Which pump is this? I'd love to know how it works, because I sure as hell don't get it. From my thinking, if it has a built-in temperature sensor, then how does it not shut off as soon as hot water from the tank starts running through the pump?
The Watts recirculating pump I have has a thermostatic valve at the faucet farthest from the pump. But this pump keeps running even when that valve is shut because it has reached temperature; i.e. the pump is not shut off by back pressure. Interestingly, with the Watts pump, there are numerous anecdotal reports that running the pump after the valve has shut led to premature valve failure. So Watts makes money on selling replacement valves
The pump is a Laing Thermotech and it is located at the plumbing(sink) farthest from the water heater. The dishwasher is close to the water heater but there is easily enough temp loss in the piping that the water at the dishwasher does not stay 120-130 degrees and most dishwasher detergents that I have used require that range. With my arrangement, by the time the recirc pump cycles off, the water is hot again at the dishwasher and stays hot until the hour is over. If I don't do this, the shot of cooler water before the fully heated water gets to the dishwasher just is unacceptable. The wash cycle is just too long and allows the piping to cool before the rinse.
