Honeywell on/off fan based upon temperature difference between thermostat and tag

[Aaron Franko]

Can anyone tell me if it's possible to toggle the fan on/off based upon the difference in temp between a tag and the thermostat?  For example the thermostat is measuring 72 and when the tag is +/-5 degrees turn on the fan.  turn off when <5 degrees?

If the answer is yes then any help with a script would be exceptional.  Thanks!

[mytaglist.com support]

I already responded to your ticket,  the app is at http://mytaglist.com/eth/app.html?3c019e9f-9704-42ce-8085-a780232d6875#addnewApp

[Simon Zimbler]

Is there any way I could find a similar app which will then generate an IFTTT trigger? I am using 2 sensors to drive a series of hot water pumps using a SONOFF 4ch switch, and I need the ability to turn off/on pumps if the difference in temp between source and destination is too small/big. Thanks!

S

[David Abigt]

There is an app in Kumo apps that looks to do that though not sure what it takes to get it working. I imagine it needs a maker URL similar to this applet. https://ifttt.com/applets/324799p-if-url-request-then-send-an-sms-to-value1-with-message-value2 Just search for IFTTT.  But I've been seeing a LOT of issues with IFTTT the last few months with errors in the activity log plus other dropped actions it listed as successful. Across a range of services. So I definitely would not use IFTTT for anything you need to work reliably. Or the cloud for anything critical for that matter. One of the great things about Wireless Tags is they can talk directly to things locally. Hot water pumps sound like something you need to work right every time.

Depends just how deep in the weeds you want to get. A similar local option would be Node RED (basically a local version of Stringify)  https://flows.nodered.org/node/node-red-contrib-wirelesstag but again that assumes a level of comfort with coding and sysadmin chores. 

But it is generally simpler to do things like that with a logic hub like SmartThings, Wink, Vera or Homeseer. 

[Simon Zimbler]

sorry to hear IFTTT isn't that reliable. I was banking on using that! Had a look at Node Red, even installed it on my QNAP, but couldn't see an easy way to add tag info or Sonoff switch...probably (definitely) a little beyond me. Do any of the other logic hubs work with Wireless Tags?

(Thanks for the help)

[David Abigt]

I use Homeseer which is just creating a virtual object then calling the right URL from Kumo to update the values. Details here https://automation.rmrr42.com/2018/10/wanting-to-monitor-your-fridge-freezer.html Others do similar things but all in diff ways. Homeseer is probably not the best choice as a first home automation system as it is aimed a it more toward installers that the entry level hubs like SmartThings and Vera.

If the pumps are AC there are a lot of options. A Z-wave plug would be simpliest You could also talk locally to a Wemo plug for example something like this https://automation.rmrr42.com/2018/12/wemo-local-control-from-homeseer.html or vis cloud as in https://automation.rmrr42.com/2018/11/etekcity-wifi-smart-plug.html Note the Etekcity service / IFTTT linkage seemed to die a few months back and I have to do that quick work around to get things working again.

If the pumps are DC it gets trickier again Z-wave is probably your simplest option though but is going to be more than a Sonoff 4 channel. I've seen posts claiming you can fool Sonoff into looking at local bridge instead of the cloud server which you could then call from Kumo but I've not tried it and I think it would be at least as hard to set up as Node RED.

[David Abigt]

One other thing too people often forget. You want to monitor the battery and / or connectivity too. I just got reminded of this by my system telling me one of my tags had been offline for an hour. So on top of triggering on temp diff > X you should also have last updated > X and probably battery < X too.