Ensure the channel selector switch inside the compartment is set to .
Use high-quality alkaline batteries. In very cold temperatures (below -10°C), lithium batteries are recommended for the outdoor transmitter. 5. Technical Specifications Temperature Range (Indoor): 0°C to +50°C Temperature Range (Outdoor): -20°C to +60°C Humidity Range: 20% -- 95% RH Frequency: 433 MHz Transmission Range: Up to 60m (Open area) wireless weather station h10515 dcf manual verified