Timex Unisex Easy Trainer Analog HRM Flex Tech Chest Strap & Mid-Size Large Digital Display Indiglo Night-Light Analog Heart Rate Sensor Automatic Activity Timer and Workout Review Water-resistant to 99 feet (30 M) Large Digital Display. NO HRM DATA Message If the watch is not receiving heart rate information, you may receive the message NO HRM DATA on the watch display. Try the following: Shorten the distance between the watch and the Heart Rate Sensor. Adjust the position of the Heart Rate Sensor and elastic chest strap. Make sure the Heart Rate Sensor pads are wet or use conductive gel. Check the battery in the Heart Rate Sensor and replace it if necessary Move away from other heart rate monitors or other sources of radio or electrical interference.