Finally putting in the minisplit

So I have a 2 zone LG minisplit with in ceiling cassettes being installed soon. I'm going to use a Remotec zxt-600. This is for the 3rd floor since I have regular forced air HVAC for the 1st two floors. My thought process is this. Can I mirror a virtual thermostat that controls the zxt-600 (which has a temp sensor in it) to my Honeywell t6-pro so that when The 1st floor heats to lets 68, that action is sent tothe zxt-600 to set the LG in on the 3rd floor to go to the same temp? My primary goal is to warm the 3rd floor (well insulated) to basically what the second floor is...(or conversely, cool)

Maybe @dylan.c , @aaiyar , or @bcopeland can chime in since they seem to be our resident HVAC junkies...

I'm not sure I'm going to be much help, but do I understand correctly that you simply want to "copy and paste" the settings from the Honeywell T6 to the Remotec ZXT-600? That shouldn't be too complicated.

EDIT: Perhaps I spoke too soon. I ASSumed the remotec was a thermostat. Neat-looking device, but I've never used one.

I don't know if copy and paste is what I'm saying. I simply want what ever I set the 1st floor thermostat to (Honeywell t6) that the zxt-600 sends the same to the mini split head. So if it's set to 68 downstairs, 3rd floor sets to 68,,,


I've got 3x Fujitsu mini-splits with a Broadlink RM3 at each one. Using a combination of the Broadlink Device Manager and RC HVAC Manager (sadly no longer maintained by the author), and RM, I do something similar -- changing setpoints on the mini-splits in response to temperature/presence from other devices.

I took a very cursory look at the virtual thermostat, and I'm not sure if there's a way to have it reference a value in another device (ie., the temperature of your T6 thermostat). Instead, you could use RM to set the temperature target (setpoint) on multiple real/virtual thermostats.

I'd suggest creating a virtual thermostat ("master") and assigning it to the Thermostat Scheduler app, as well as putting it on a dashboard in HE for an easy interface to change the temperature, outside of the Thermostat Scheduler app.

Using RM, write a rule that is triggered on any change in the "master" (virtual) thermostat setpoint and then send that setpoint to the T6 (directly as a device) and to the minisplit via the Remotec. Bonus points for sending changes in the fan level, etc. Doing this through RM also allows you to use any offset in the heating devices -- for example, if the T6 is set to 68F, the minisplits may only need to be set to 64F to get the same level of comfort, or you may need an offset between the different minisplit zones (and different offsets, in the opposite direction, between heating & cooling functions).

All temperature changes would be initiated through the virtual master thermostat, and sent to each device, rather than having the minisplit (virtual) thermostat itself mirror the T6.

1 Like

If the ZXT600 supports your mini split with all of the commands included in the HE device driver, it should do exactly what you want. It looks like most of the common thermostat commands are there, so just a matter of writing a rule that sets the mode and setpoint to match the Honeywell. Shouldn't need any virtual thermostats or other trickery.


If this proves necessary, there is a community device driver for "Advanced vThermostat" device that uses a temp sensor to create a virtual thermostat. It's intended to use with a smart plug and a sensor to control space heaters and the like.

1 Like

Yeah I wasn't sure. I'm also not sure if the zxt will give me any actual feedback from the unit (on, off, heat, cool etc) or if I'm just gonna have to rely on maybe the temp sensor in the zxt and maybe a shelly relay or something similar to show heating/cooling status..

I want to say it is transmit only, but I have not personally verified that. The similar zxt-120 that I have is not bidirectional anyway, and the description and manuals for these devices look very similar.

I also had a very hard time finding a code that worked for my Midea sourced minisplit, due to the age of this Remotec device, the list of codes wasn't up to date and it was missing many brands and codes in the code book. I literally had to try every single code listed until I found one that worked, but I was eventually able to find one that worked.

Luckily tomw wrote an integration for Midea sourced units, and I have been using that pretty successfully. (Thanks @tomw :+1: )

Personally, I would use either the LG Wifi dongle (not sure of any integrations with Hubitat?) or maybe a physical thermostat conversion kit (I would think they make one for LG?) so you can use a standard thermostat of your choice. You will have a much better experience with either of these than the Remotec with in my opinion.


They make a thermostat kit but it only handles on/off/auto/heat/cool. For temp and louver adjustment you still need the remote.

The zxt-600 can be programmed from any IR remote. Hell I think it can be programmed with a tv remote...

1 Like

That was a very clunky process. I tried it.

Usually is. I remember early universal remotes you had to do that with.... ugh

1 Like

Hi, FYI, I've developed some zoning smartapps for this use case and many more using the concepts of master and slave thermostats.

You can even create a virtual zone device to control some specific sections of your home (using some optional smart vents such as Flair or Keen Home).

For more information

Thanks, I'll take a look at them...

Could you just put a temperature sensor in the discharge of the wall unit to get the feedback that you want? Maybe a current sensor at the outdoor unit as well?

The ZXT-600 has it's own temp sensor. I made it simpler. I basically set whatever the main 1st floor thermostat and the 3rd floor mini splits to be the same temp. When temps reach that point (let's say 74 degrees) it issues the off command. Works well actually.

That is good to hear! Just starting to look at adding cooling to my house that only has baseboard heating controlled by Nest thermostats. Good integration is the key where there are two thermostats in a room. I'm going to want to disable mini-split heating, for example, when the efficiency drops below that of the boiler due to low outside air temps, as well as make sure that my wife can't cross the heating and cooling setpoints on the two separate thermostats.

Regarding the temp sensor, I was thinking you might want one right in the discharge of the indoor unit - not for control, but so that you can get good feedback as to its status and performance. Something that can be added at any time if needed.

1 Like