How to set and use variables



Day one of Vera.

Added all the ZWave TRVs, Room Thermostats along with a ZWave Temp sensor, some zwave plugs and a zwave Heating/Hot Water Controller.

I am trying to find a way to set a variable HeatingDemand=True/False when ever any of the thermostats hits a high or low temp.

On the HeatingDemand=True then turn on Heating and then the reverse for False.

I just can’t find where or how to manage variables in Vera.

Any ideas/suggestions would be helpful.



Hi Busta,

Have you looked at the wiki pages especially the development ones?

Cheers Rene

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@Busta999 Welcome! Your question… may not be the right question. Let me ask you this: do you want to set a variable, or do you want to turn heating on and off in response to your temperature sensors?

My guess is you really want to turn heating on and off, and you’ve decided that setting a variable is a step on the way to doing that. That’s not really the Vera way of doing things, and I think what you really want to ask is, how do I use my temperature sensors to make a decision about whether a heating unit should be on or off, and then operate that heating unit accordingly?

On Vera:

  1. You can use a Vera-native scene. A scene will allow you to set up a device trigger, wherein you can look at the current value of a sensor and turn devices on or off accordingly. You may need to set up several scenes–separate scenes for on and off logic, and then as many of those as needed to control the various “zones” (a zone being an area whose temperature is controlled by one or more heating units and monitored by one or more temperature sensors).
  2. Native scene triggers are a bit limited on Vera, so you may want to go to a program logic plugin like Reactor, Rules Engine, or PLEG. These allow you to set up much more complex rules for triggering than Vera scenes. They come with a learning curve, but once you get a grip on them, there’s little that can be done with Vera that will be outside your reach.
  3. There are plugins that do exactly what you are asking. One such plugin is AutoVirtualThermostat, which is purpose-built to read temperature data from one or more temperature sensors, and operate a heating and/or cooling device accordingly. It implements the behaviors of a standard thermostat, and has a thermostat UI.
  4. If you literally want to dive deep, you can start learning Lua programming and the Luup engine that provides the interfaces you need, but that’s a steep curve for the moment and likely not necessary for you to solve the problem I think you are trying to solve. You’ll benefit from doing it eventually, but I wouldn’t start there when simpler options are available and you are now only on day two.
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Thank you so much.

The way I had done in other HAs was for a Trigger that mapped every room Target against actual and if any of them was under target set Demand On.

When all were above target turn off heating.

The TRVs stopped rooms from overheating.

Looks like first stop is AutoVirtualThermostat - I’ll start there.

Many thanks for the time spent explaining this - very much appreciated.


Sorry to ask but…

I installed Smart Virtual Thermostat - and I get an error message after it has finished installing on the device - Lua Startup Failure.Can’t Detect Device.

I have un-installed and re-installed and I get the same error.

The Device will not allow to configure it ‘Error Device Not ready’

Any clues or insights - this a brand new install of Vera with all the latest updates.

So not sure how what to do with this now…


Wrong plugin. You want AutoVirtualThermostat. Smart Virtual Thermostat is no longer supported. One of the hazards of the current environment is that Vera’s plugin marketplace is littered with plugins that are no longer supported, and many don’t even work on current firmware or UI.


I’m finding that out the hard way :slight_smile:

All part of the learning curve.

A lot of the issues could be easily removed by a bit of curating ?

Searches on Google are limited as they take you to pages in Vera Support site that are no longer there :frowning:
Adds a little more to the gradient :slight_smile:

I’ll get there - I have very low expectations of Vera - I just want it to do zwave Heat and Hot Water systems :slight_smile:

Again thanks for your help.

Will need to figure out why Vera keeps losing zwave Spirit TRVs in the same room as the Vera Edge… and not the ones at far reaches of the house…

Next puzzle.


OK last request today…

Upon request of Reload LUUP I get ERROR:Module not found:port_3480

Is that a problem ?

I am setting up AVT for each zone/room that I have Zwave Spirit TRVs in.

I am setting up for Eco (effectively Night/away/possibly holiday) and Comfort for when the room is in use, i.e. Guest Bedrooms/bathrooms stay in Eco until they are used then I’ll switch to Comfort.

In pretty much every room/zone I have a Secure SR321 Battery Zwave Thermostat and the TRV.

A problem I do foresee is that for reasons best known to Vera it has added the zwave SSR302 as THREE devices, a Boiler - a Switch (Heating) and a Switch (Hot Water), it does look like the AVT will only turn on boiler. I’ll check that.