RadioThermostat Binding

This binding connects RadioThermostat/3M Filtrete models CT30, CT50/3M50, CT80, etc. with built-in Wi-Fi module to openHAB.

The binding retrieves and periodically updates all basic system information from the thermostat. The main thermostat functions such as thermostat mode, fan mode, temperature set point and hold mode can be controlled. System run-time information and humidity readings are polled less frequently and can be disabled completely if not desired. Humidity information is available only when using a CT80 thermostat and I have noticed that the humidity reported is very inaccurate.

The main caveat for using this binding is to keep in mind that the web server in the thermostat is very slow. Do not over load it with excessive amounts of simultaneous commands. When changing the thermostat mode, the current temperature set point is cleared and a refresh of the thermostat data is done to get the new mode's set point. Since retrieving the thermostat's data is the slowest operation, it will take several seconds after changing the mode before the new set point is displayed. The 'Program Mode' command is untested and according to the published API is only available on a CT80 Rev B.

Supported Things

There is exactly one supported thing type, which represents the thermostat. It has the rtherm id. Multiple Things can be added if more than one thermostat is to be controlled.


Auto-discovery is supported if the thermostat can be located on the local network using SSDP. Otherwise the thing must be manually added.

Binding Configuration

The binding has no configuration options, all configuration is done at Thing level.

Thing Configuration

The thing has a few configuration parameters:

Parameter Description
hostName The host name or IP address of the thermostat. Mandatory.
refresh Overrides the refresh interval of the thermostat data. Optional, the default is 2 minutes.
logRefresh Overrides the refresh interval of the run-time logs & humidity data. Optional, the default is 10 minutes.
isCT80 Flag to enable additional features only available on the CT80 thermostat. Optional, the default is false.
disableLogs Disable retrieval of run-time logs from the thermostat. Optional, the default is false.


The thermostat information that is retrieved is available as these channels:

Channel ID Item Type Description
temperature Number:Temperature The current temperature reading of the thermostat
humidity Number:Dimensionless The current humidity reading of the thermostat (CT80 only)
mode Number The current operating mode of the HVAC system
fan_mode Number The current operating mode of the fan
program_mode Number The program schedule that the thermostat is running (CT80 Rev B only)
set_point Number:Temperature The current temperature set point of the thermostat
status Number Indicates the current running status of the HVAC system
fan_status Number Indicates the current fan status of the HVAC system
override Number Indicates if the normal program set-point has been manually overridden
hold Switch Indicates if the current set point temperature is to be held indefinitely
day Number The current day of the week reported by the thermostat (0 = Monday)
hour Number The current hour of the day reported by the thermostat (24 hr)
minute Number The current minute past the hour reported by the thermostat
dt_stamp String The current day of the week and time reported by the thermostat (E HH:mm)
today_heat_runtime Number:Time The total number of minutes of heating run-time today
today_cool_runtime Number:Time The total number of minutes of cooling run-time today
yesterday_heat_runtime Number:Time The total number of minutes of heating run-time yesterday
yesterday_cool_runtime Number:Time The total number of minutes of cooling run-time yesterday

Full Example

0_pgm=Program A
1_pgm=Program B


radiothermostat:rtherm:mytherm1 "My 1st floor thermostat" [ hostName="", refresh=2, logRefresh=10, isCT80=false, disableLogs=false ]
radiothermostat:rtherm:mytherm2 "My 2nd floor thermostat" [ hostName="mythermhost2", refresh=1, logRefresh=20, isCT80=true, disableLogs=false ]


Number:Temperature  Therm_Temp  "Current Temperature [%.1f °F] " <temperature>  { channel="radiothermostat:rtherm:mytherm1:temperature" }
// Humidity only supported on CT80
Number Therm_Hum                "Current Humidity [%d %%]" <temperature>        { channel="radiothermostat:rtherm:mytherm1:humidity" }
Number Therm_Mode               "Thermostat Mode [MAP(]" { channel="radiothermostat:rtherm:mytherm1:mode" }
// The Auto/Circulate option will only appear for CT80
Number Therm_Fmode              "Fan Mode [MAP(]"         { channel="radiothermostat:rtherm:mytherm1:fan_mode" }
// Program Mode only supported on CT80 Rev B
Number Therm_Pmode              "Program Mode [MAP(]"     { channel="radiothermostat:rtherm:mytherm1:program_mode" }
Number:Temperature  Therm_Setpt "Set Point [%d]" <temperature>                  { channel="radiothermostat:rtherm:mytherm1:set_point" }
Number Therm_Status             "Status [MAP(]"          { channel="radiothermostat:rtherm:mytherm1:status" }
Number Therm_FanStatus          "Fan Status [MAP(]"     { channel="radiothermostat:rtherm:mytherm1:fan_status" }
Number Therm_Override           "Override [MAP(]"        { channel="radiothermostat:rtherm:mytherm1:override" }
Switch Therm_Hold               "Hold"                                          { channel="radiothermostat:rtherm:mytherm1:hold" }

Number Therm_Day       "Thermostat Day [%s]"                                 { channel="radiothermostat:rtherm:mytherm1:day" }
Number Therm_Hour      "Thermostat Hour [%s]"                                { channel="radiothermostat:rtherm:mytherm1:hour" }
Number Therm_Minute    "Thermostat Minute [%s]"                              { channel="radiothermostat:rtherm:mytherm1:minute" }
String Therm_Dstmp     "Thermostat DateStamp [%s]" <time>                    { channel="radiothermostat:rtherm:mytherm1:dt_stamp" }

Number:Time Therm_todayheat "Today's Heating Runtime [%d %unit%]"       { channel="radiothermostat:rtherm:mytherm1:today_heat_runtime" }
Number:Time Therm_todaycool "Today's Cooling Runtime [%d %unit%]"       { channel="radiothermostat:rtherm:mytherm1:today_cool_runtime" }
Number:Time Therm_yesterdayheat "Yesterday's Heating Runtime [%d %unit%]"   { channel="radiothermostat:rtherm:mytherm1:yesterday_heat_runtime" }
Number:Time Therm_yesterdaycool "Yesterday's Cooling Runtime [%d %unit%]"   { channel="radiothermostat:rtherm:mytherm1:yesterday_cool_runtime" }

// A virtual switch used to trigger a rule to send a json command to the thermostat
Switch Therm_mysetting   "Send my preferred setting"


sitemap radiotherm label="My Thermostat" {
    Frame label="My 1st floor thermostat" {
        Text item=Therm_Temp icon="temperature" valuecolor=[>76="orange",>67.5="green",<=67.5="blue"]
        // Humidity only supported on CT80
        Text item=Therm_Hum icon="humidity"
        Setpoint item=Therm_Setpt label="Target temperature [%d °F]" visibility=[Therm_Mode==1,Therm_Mode==2] icon="temperature" minValue=60 maxValue=85 step=1
        Selection item=Therm_Mode icon="climate"
        Selection item=Therm_Fmode icon="fan"
        // Program Mode only supported on CT80 Rev B
        Selection item=Therm_Pmode icon="smoke"
        Text item=Therm_Status icon="climate"
        Text item=Therm_FanStatus icon="flow"
        Text item=Therm_Override icon="smoke"
        Switch item=Therm_Hold icon="smoke"

        // Virtual switch/button to trigger a rule to send a custom command
        // The ON value displays in the button
        Switch item=Therm_mysetting mappings=[ON="Heat, 58, hold"]

        Text item=Therm_Day
        Text item=Therm_Hour
        Text item=Therm_Minute
        Text item=Therm_Dstmp

        Text item=Therm_todayheat
        Text item=Therm_todaycool
        Text item=Therm_yesterdayheat
        Text item=Therm_yesterdaycool


rule "Send my thermostat command"
  Item Therm_mysetting received command
  val actions = getActions("radiothermostat","radiothermostat:rtherm:mytherm1")
  if(null === actions) {
      logInfo("actions", "Actions not found, check thing ID")
  // JSON to send directly to the thermostat's '/tstat' endpoint
  // See RadioThermostat_CT50_Honeywell_Wifi_API_V1.3.pdf for more detail
  actions.sendRawCommand('{"hold":1, "t_heat":' + "58" + ', "tmode":1}')