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September 08, 2026 5 min read
Instruction manual for the La Crosse Alerts add-on Remote Water Detector & Temperature/Humidity Monitor with early-warning text and email alerts.
Instruction manual for the La Crosse Alerts Add-On Remote Water Detector & Temperature/Humidity Monitor (Model D012.104.E1) — a wireless sensor that detects water leaks and monitors ambient temperature/humidity, sending early-warning text and email alerts via the La Crosse Alerts Gateway.
Frozen pipes that crack and burst damage a quarter-million properties every year. The La Crosse Alerts Remote Water Detector provides early-warning alerts of a water leak before it causes extensive damage, and monitors temperature/humidity levels that could indicate frozen-pipe risk or mold growth. Water damage can originate almost anywhere — frozen or broken pipes, dishwasher/washing-machine leaks, roof or basement leaks, foundation cracks, sump pump overflow, or weather-related flooding.
The wireless sensor transmits water status, temperature, and humidity to a La Crosse Alerts Gateway (sold separately, not included) within a 200 ft. wireless range. The Gateway connects to your existing network router and uploads readings to your account at lacrossealerts.com, where you can monitor from a smartphone, tablet, or computer and set custom email/text alerts.
Additional equipment needed (not included): Two fresh AAA 1.5V alkaline batteries; two-sided tape as needed; an existing La Crosse Alerts Internet Gateway (with AC adapter and LAN cable); a browser with high-speed internet; and a network router.
The included Activation Key provides 1 year of Enhanced Service (early-warning text/email alerts) plus 4 additional years of Basic Service (standard remote monitoring). Lost your Activation Key Card? Contact La Crosse support at lacrossetechnology.com/support/alerts or (608) 785-7920.
Place the H2O sensor on the dry floor or against a wall near your foundation, water heater, sump, plumbing, washer, aquarium, or dishwasher to monitor for leaks. Important: test the sensor in the chosen location for at least 1 hour and confirm readings at lacrossealerts.com before permanently mounting; move closer to the Gateway if signal is lost.
The low-battery icon appears on the LCD, and you'll receive an email/text alert, when battery power is low — change batteries immediately. The LED turns on briefly after changing batteries, then off to save power. Stored sensor data is not affected by a battery change.
Once the sensor is activated and building a log, data can be downloaded as a CSV file (view with Microsoft Excel, Google Docs, or similar).
| Temperature Range | -40°F to 140°F (±0.2°F resolution); "OFL" displayed if outside range |
| Humidity Range | 3% to 99% |
| Transmission Range | 200 ft. (60.96 m) in open space |
| H2O Sensor Cable | 6 ft. detachable, detects WET/DRY; displays last reading if disconnected |
| Sensor Battery Power | 2x AAA Alkaline, IEC LR03, 1.5V |
| Battery Life | Approximately 24 months |
| TX70U-IT Size | 5.23"H x 0.76"W x 1.44"D |
| D000.104 Sensor Size | 0.26"H x 1.77"W x 1.17"D |
La Crosse Technology, Ltd. provides a 1-year limited warranty against manufacturing defects in materials and workmanship, valid only for products purchased and used in North America by the original purchaser. Warranty excludes damage from accident, unreasonable use/neglect, shipping, cosmetic/accessory deterioration, failure to follow instructions, unauthorized repairs/alterations, non-home use, unintended applications, or signal-interference issues. La Crosse will repair or replace defective units at its option with new or reconditioned parts; replacement parts assume the remaining original warranty or 90 days, whichever is longer. Owner pays shipping to the service center; La Crosse pays ground return shipping (USA only). La Crosse is not liable for incidental, consequential, or punitive damages. This product is not for medical use and is not a toy — keep out of children's reach.
Service providers may charge for alert services; standard messaging/data rates apply. La Crosse is not liable for accuracy, usefulness, or availability of data transmitted via the service.
Protected under US Patents 5,978,738; 6,076,044; 6,597,990. FCC Statement: This device complies with Part 15 of the FCC rules — operation is subject to (1) may not cause harmful interference, and (2) must accept any interference received, including interference that may cause undesired operation.
La Crosse Technology, Ltd., 2817 Losey Blvd. S., La Crosse, WI 54601. Support: lacrossetechnology.com/support/alerts, phone (608) 785-7920.
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