Sensing thermostat heating/cooling calls

The suggestion to look at whether the blower is running would work for some of what I would like to accomplish but not everything. We have three zones in our house. For some purposes, I would like to distinguish between a call for the basement, a call for the main floor, and a call for the upstairs. For example, I would like to override the default logic for staging the furnace and have the furnace run on low stage when only one zone is calling and run on high stage if two or more zones are calling.

Maybe put the current sensor switch on the damper motor?

But that will only read when the damper is moving, not when it is done closing/opening, right?

Depends if it is fail last, fail open, or fail closed?

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Correct. However, if you know which ones moved, you can approximate which zone is active.

@JasonJoel beat me to it. Also, it means that you can't miss any of the damper motions because they will become out of sync. And what about a motion to close followed immediately by a motion to open that is too close together for your current sensor to reach back to low? It would also be out of sync.

I don't keep track of anything in software that can't eventually be polled from somewhere or isn't automatically reset. Too unpredictable.

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Interesting idea. I will think about whether that gives me the info I need. I believe that my zone dampers are normally open. The zone controller opens all of the dampers when either all of the zones are calling or none of the zones is calling.

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You know, I just thought of something when I saw another thread talking about a device. What about the Sage doorbell sensor? It is designed to detect current flow in a 12-24VAC circuit and is battery powered. Comes with 3 wires so you can monitor 2 circuits simultaneously. Best part, it;s only $5 on ebay at the moment.

I can't see why this wouldn't work. Can anyone else?


I ordered a Sage doorbell sensor. I will try it and let everyone know if it works or not.


Holy cow, You read my mind. As I was reading down from the top, I thought the same thing and then saw your post. I'm a day late and a dollar short

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I happened to be reading the other thread about the driver for the Sage right after reading this one. So, in a way I kinda cheated. :wink:

Reid - I’ll be very interested in how these work with a long on/off signal vs the short signal from a doorbell.

You will probably have to re-write the appears from what I have been able to find, the device should send a signal every so many seconds as long as the button is pressed. This may flood your zigbee with messages if it is on for an extended period of time. Depending on how long you are looking to monitor your network and see if this causes zigbee lags.

If I need to learn how to write a driver, or at least modify one, that will add some time to my project. But, that is a skill I have been intending to add to my repertoire, so this could be what forces that to happen.

There's a ported driver on another thread for the sage here on the forum. What it will really come down to is how long is the re-fire rate. You might be only able to detect the start of a cycle reliably. The end might be a bit dodgy.

As discussed in another thread, it appears that modifying the driver is not going to remedy the issue of the device flooding the network with tons of messages (and probably going through batteries quickly). I am planning to resort to a polling approach. I plan to connect the white wire of the sensor to common via a switch, such as one of the relays of a Zooz ZEN16. To test the state, I need to turn the switch on for about a second then process any resulting events. I think I will be able to accomplish this in a Rule Machine rule. If not, I will have to learn to write an app.

Have you looked at this? I am not sure if it will do exactly what you want, but maybe you could try it?

That won't do it, it just uses the state that the thermostat reports and tells you the run time for each state so you can see usage statistics, sorry.

This app requires you to have a thermostat device in Hubitat. If my thermostats were easy to put into Hubitat as devices, I would already have solved my issue.

My attempt to read the thermostat outputs with the Sage Doorbell sensors did not work. The sensors flooded my ZigBee spectrum with events. My next line of investigation is the Arduino circuit posted here.

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