Two Thermostats (TR40) on 1 Zone

[iostream212]

I have a two story and I would like to have one thermostat downstairs and one upstairs. I am working with two RCS TR40. I want to turn my single zone HVAC system 'on' or 'off' from either location. Is anyone familiar if the TR40 can be setup to do this and if so how to wire? I am guessing I would split the HVAC connections between the two Control Units... I am just unsure how to sync the system so if one thermostat is turned 'on' the other thermostat is updated and the WDU displays 'on' as well.

I am also working with a RS485 to TCP/IP converter. I could write a program that sends the changes to the other WDU when thermostat settings are manually changed.

Also too I could use my ELK and M1XSP if that provides an easier way to control.

Thanks!

 

[mustangcoupe]

I have a two story and I would like to have one thermostat downstairs and one upstairs. I am working with two RCS TR40. I want to turn my single zone HVAC system 'on' or 'off' from either location. Is anyone familiar if the TR40 can be setup to do this and if so how to wire? I am guessing I would split the HVAC connections between the two Control Units... I am just unsure how to sync the system so if one thermostat is turned 'on' the other thermostat is updated and the WDU displays 'on' as well.

I am also working with a RS485 to TCP/IP converter. I could write a program that sends the changes to the other WDU when thermostat settings are manually changed.

Also too I could use my ELK and M1XSP if that provides an easier way to control.

Thanks!

I actually just installed my TR40 today, stage 1 is done it controls the furnace stage 2 will be connecting it to my ELK via a M1XSP so I can control the heat when I leave from work and set it back when the system gets armed. I think in your case this would also be the best idea also. I think it could be wired correctly to have both TR40's working BUT they wouldn't reflect the set point you are setting on #2 ect... with the elk you cant set a temp to be measured upstairs but you can control on/off by adjusting the downstairs setpoint

 

[myyaz33]

Did you ever find a solution to this? I have the exact same issue, I have two TR40 thermostats but only 1 zone. Experts, can it be done? Even if I could just wiring the one WDU as a remote temp sensor maybe I could average the temps?

 

[dBeau]

I have a two story and I would like to have one thermostat downstairs and one upstairs. I am working with two RCS TR40. I want to turn my single zone HVAC system 'on' or 'off' from either location. Is anyone familiar if the TR40 can be setup to do this and if so how to wire? I am guessing I would split the HVAC connections between the two Control Units... I am just unsure how to sync the system so if one thermostat is turned 'on' the other thermostat is updated and the WDU displays 'on' as well.

I am also working with a RS485 to TCP/IP converter. I could write a program that sends the changes to the other WDU when thermostat settings are manually changed.

Also too I could use my ELK and M1XSP if that provides an easier way to control.

Thanks!

I have an elk setup with a bunch of Aprilaire 8870's. I'll make some guesses based on what I know about them. First if you wire both tr40 in parallel with your heating system, if either were to call for heat, you would get it. This alone might be what you want... but probably not. In a lot of single zone homes, the 2nd floor is too hot when the 1st floor is just right. Likewise, the 1st floor is too cool when the 2nd floor is just right. For this reason, you might want to turn off the 1st floor tr40 when you are on the 2nd and turn off the 2nd floor tr40 when you are on the 1st. This way, it will be just right where you are. Using elk rules, you can notice when the settings on one tr40 changes and then send those changes to the other (will be a pile of tedious rules). The 8870s have a mode setting that can be heat/cool/auto/off. Further, this mode can be changed by hitting a button on the tstat. I'll assume the tr40 is the same. So, whenever the mode on one changes to heat, have rule set the other to off. Just toggling the mode might be the best solution as this would allow different set point on each floor and a means to indicate which of the two you currently care about.

Getting these rules right will be fun because the elk wont know if the change to the settings were due to a rule firing or a user button press. You'll have to be careful or weird things will happen. But it's completely do-able.