3
Installation Instructions
Important note RF products: Ensure that there are no large metal objects, such as boiler 
cases or other large appliances, in line of sight between the transmitter and receiver as 
these will prevent communication between thermostat and receiver. 
Installation Instructions
GB
Features
RET B (RF) / RET B-LS (RF) / RET B-NSB 
(RF)
Contact rating    10 - 230 Vac, 3 (1) (excl. North America)
Contact rating 
(N.America)
10 - 24 Vac, 50/60Hz, 3(1)A
Temperature Accuracy ±1°C
Contact Type SPDT Type 1B
Transmitter frequency 433.92 MHz  (RF models)
Transmitter range 30m max (RF models)
Power Supply 2 x AA/MN1500 alkaline batteries
Control Pollution 
Situation
Degree 2
Rated Impulse Voltage 2.5 kV
Designed to meet BS EN 60730-2-9 (EN 300220 for RF)
Ball Pressure Test 75°C
Temperature Range 5-30°C
Dimensions (mm) 85 wide x 86 high x 42 deep