Wirsbo Radiant Thermostat (WT 1), Heat Only, Two-wire

Application: Heat Only
Stages: 1 Heat
Programmability: Non-Programmable
User Interface: Push Button
Mount: Vertical
Power Method: Hardwired
Operating Voltage: 24 VAC +/-10%
Voltage: Low voltage
Wiring: Two-Wire
Color: White
Height: 5″
Length: 2.72″
Depth (Inches): 0.91″
Max. Load: 1.3A at 24 VAC
Display Range: 32 to 99°F
Resolution: 1° Displayed
0.25° Calculated



  • When it comes to radiant heating systems, not just any thermostat will do. That’s why professional installers choose Wirsbo Radiant Thermostats. They are the first thermostats designed specifically for radiant floor heating.
  • Why a special thermostat for radiant floor heating? The dynamics of a radiant heating system differ from typical baseboard or warm air heating systems. Radiant systems always heat objects and mass, and need to be addressed differently than conventional thermostat logic.
  • The Wirsbo Thermostats offer two different control methods to handle this condition–differential and pulse-width modulation. Differential–When the measured room temperature falls 1F (0.5C) below the desired room setting, the control devices wired to the thermostat turns on.
  • Pulse-width Modulation–When the condition exists where the room temperature is 1 to 3F (0.5 to 1.5 C) below the room setting, the thermostat manages the on-and-off cycle using pulse width modulation. The on-and-off times vary depending on the difference between the room and set temperatures. The farther away the room temperature is from setpoint, the longer the on time. This prevents the room temperature from rising above the set temperature. The heating system runs continually at room temperature differences greater than 3 degrees F below setpoint.
  • These thermostats also feature digital filtering. This means that the thermostat measure the room temperature continuously. The thermostat’s sensor detects even the smallest change, making it better able to react to a room’s changing conditions. If all the room’s temperatures were displayed as they are sensed, the temperatures shown would appear erratic and inconsistent. Filtering works by averaging the sensed values to ensure a smooth operation and display.
  • Wirsbo offers three thermostat models: Heat Only (A3030101), Heat and Cool (A3030102) and Heat Only, Three-wire (A3030103). The Heat Only (A3030101) and Heat and Cool (A3030102) thermostats are designed to operate in heating mode over two wires. These types of thermostats obtain their power for operation from taking voltage from the connected wiring. Different from other industry power-sharing thermostats, these eliminate any need for a third wire or battery, which makes the thermostats simple to install, wire and service.
  • And for those times when the two-wire thermostats aren’t appropriate because of incompatibility with some third-party devices, Wirsbo also offers the Heat Only, Three-wire (A3030103).
  • No matter which thermostat you use, when you’re selling radiant, you’re selling comfort, The Wirsbo Radiant Thermostats feature special built-in software that provides the ultimate control that standard thermostats–when used with radiant heat–simply cannot. There’s no overshoot, no undershoot–just constant, even comfort. Your customers will love the distinctive design and easy-on-the-eyes readout. But most of all, they will love the true radiant comfort only Wirsbo Radiant Thermostats provide!