I have a closed loop hot water circulation line on my water heater. It circulates via a pump that has a 24 hour programmable timer. Right now I have it set to circulate during peak periods. I’d like to throw some smarts to it so I can have the ability to activate the pump when the hot water line reaches a specific temp. Any idea of any sensor devices out there that can help me out? The Wireless Sensor Tag (https://store.wirelesstag.net/products/wireless-tag) could work but it’s meant to measure room temp… I think. I have a wemo plug that the pump would be plugged in to and of course my hub to control it.
Check this out.
Would let you use an external sensor mounted to the pipe.
There are other ways I’ve seen on the board you just have to search them out.
you can strap any air temperature sensor to the pipe and insulate around it. Response is slower than it could be, but it works fine. You could take the board out of the enclosure and reduce the delay - don’t short any components to the pipe.
Before choosing any particular sensor, be sure to check the specs to make sure it can accurately measure the temp of your hot water (typically 120-140 F). Also note that by code, the hottest temperature of water coming out of your tap should not be more than 120F.
Grundfos now makes a fully automatic recirculator that automagically learns usage periods and shuts off when the temp reaches the setpoint. http://ca.grundfos.com/products/find-product/COMFORT.html Probably not cheaper than using sensors and controls though, YMMV.