
$39.95
See if it's really the one
Search with this product to compare it, find similar styles, or turn up something better before deciding.
Honeywell 5821 Wireless Temperature Sensor & Flood Detector The Honeywell 5821 is a multi-purpose wireless sensor. By itself it can be used to sense either a rise in temperature or a lowering of temperature in the location where it is installed. It has five different temperature settings that can be detected. This sensor also has add on probes that you can use. One is a T280R which lets you monitor freezer or refrigerator temperature. The other probe is the 470PB which will convert the 5821 into a flood detector. The 5821 can be used multiple ways and is a must for those who worry about freezing or floods. Specifications: Operating Temperature: 14 F (-10 C) to 104 F (+40 C) Operating Voltage: 3.2VDC Dimensions: 3.1" length, 1.6" wide, 1.0" depth Sensor Parameters: Cold Temperature (Freeze) Detector 45° F (7° C) Warm Temperature Detector 75° F (24° C) Hot Temperature Detector 95° F (35° C) Refrigerator Failure Detector 42° F (6° C) Freezer Failure Detector 10° F (-12° C) Hysteresis 3° F (-16° C) Flood Sensor inch of water covering the probe Response Time Tolerance +50%, -20% Temperature Measurement Accuracy (internal temp. sensor or external temp. probe) 3° F (-16° C) Features: Five selectable temperature ranges to choose from (hot, warm, cold, refrigerate and freeze) Remote Temperature Probe available (T280R) ideal for refrigerator and freezer monitoring Flood detection with 470PB External Probe for a wide range of applications; including bathrooms, laundry rooms and basements Up to 10 year battery life, which reduces user maintenance Completely wireless, which greatly reduces installation time and maximizes placement options Capable of monitoring cold (45° F) temperature and flood detection simultaneously 5821 Installation manual 5821 Data sheet
Have a question about this?
We currently ship within the US, with more countries coming soon.
Final cost and dates are confirmed at checkout.
🇺🇸 Ship from USA · On Agora since 2025
$39.95