1. Please make sure the channel chosen on the display unit matches the channel option chosen on the outdoor sensor.Ordering more sensors by searching ASIN: B0BMTNC9DR / B0963DKBQP
2. Do not use heavy duty or rechargeable batteries. The wireless sensor requires lithium batteries in low temperature conditions. Cold temperatures would cause alkaline batteries work improperly.
3.To manually restart the RF registration, press and hold the “CH” button for 3 seconds. The display unit will now search for the RF signal for the next 3 minutes.
4.(!Important)The waterproof level of the sensor is IP23, which is a splash-proof level. We recommend not to expose the sensor to rainwater and direct sunlight, which will affect the accuracy of the sensor and even cause damage to the sensor.
5.In normal display mode, press UP button to switch between Celsius and Fahrenheit
Please read the user manual before using the indoor outdoor thermometer.