Help with dual Honeywell YTH8320ZW1007 thermostats.

Other Devices & Integrations Climate Control & Temperature Sensors
1

I’m a newbie with townhouse that has dual HVAC systems each controlled by a Honeywell Z-wave thermostat. I am trying to turn the fan (only) on for the second floor unit when the heat is running on the first floor unit. Is there a simple way to do this? I don’t want the fan to run all the time, just when the lower unit is calling for heat.

Thanks.

2

Makes sense to me.
I have noticed that if I have the main floor set to 70 my upstairs will be about 68 to 69 with the furnace off so I can see value in what you are asking for.
I’ll be watching to see if you come up with anything.

3

You can do this with the PLEG plugin.
You would have an input device variable that watches the thermostats variable that indicates it is NOT IDLE. Then you would use this to command the other thermostat into FAN ON mode. Then the thermostat goes back to idle … it would command the other thermostat into FAN AUTO mode.

4

I can’t find a variable that tells me when it is running. The advanced listing shows a “modestate” value of “idle” even when the unit is running. Is there another variable that I should be adding to the liest? I have tried to find the variable listing for the thermostat (Honeywell YTH8320ZW1007) with no success.

Thanks for the help.

Bob

5

You have to refresh the browser to see a change … but thats the variable.
The value it shows is the value of the thermostat when the Vera Window was opened.

The PLEG will not have this problem … it will see changes immediately.

6

Thanks. I can see the variable and its current state. It appears that I am incapable of correctly programming the condition and constantly get Lua Startup Failure. Are there any examples anywhere of step-by-step with proper syntax. I’m sure the problem is my own limitations, but I’m just about to give up.

7

PLEG Device Inputs:
Name Device Property
TState1 Bound to Thermostat 1 ModeState property.

PLEG Condition:
Name Expression
TStateActive1 TState1 ne ‘Idle’
TStateInactive1 TState1 eq ‘Idle’

Actions:
Condition Device Commands
TStateActive1 Turn Thermostat 2 fan to ON
TStateInactive1 Turn Thermostat 2 fan to AUTO

8

I really appreciate your help. I entered the syntax that you sent. Unfortunately I now get Lua Startup Failed. I tried removing and reinstalling PLEG and re-entering all the data with the same result.

9

What is the Startup LUA message ?

10

The message is “Program Logic Event Generator[20] : Startup Lua Failed”. Also, if you click on Arm, it says “Device Not Ready”.

11

I’m not sure what changed, but I updated my firmware to 1.5.622, removed PLEG and reinstalled it, and set up the system again. It’s working perfectly now. Thanks for all the help!