Replace battery door and four screws. After you replace the heart rate monitor battery, you may need to pair your heart rate monitor with the device again. Pairing instructions may vary from device to device. Please refer to the owner's manual for pairing instructions. For additional care instructions, see the Caring for the Heart Rate Monitor Personally I don’t have problems using an optical wrist HRM for indoor rowing but many people do. As for chest HRMs, unless you need the extra functionality of the Garmin models, the Polar H10 is bullet proof and one of the most accurate (according to lab tests) on the market. Here’s what I’ve done so far: (1) Verified the original issue was the battery was dead. Took out old battery, let module discharge (15min), put in new battery and verified it can connect to my Garmin Edge 520 biking computer (which it originally came with). (2) Disconnected from Garmin Edge 520 and tried to pair with Zwift via Zwift New Garmin HRM Dual and had no issues for a couple of rides. My setup is my iPhone X, Garmin HRM Dual, and Wahoo Kickr Core. Worked well on Wed, but on Thurs, when I tried to ride, I realised that my HR was at a flat 108. I then had a pop-up on my iPhone that HRM wanted to connect. I pressed yes. Not sure which app was triggering that pop-up. I learned while in the water do not attempt to modify the current work-out while the HRM-TRI is under water. It will lose the connection with the 920, I ended up losing half of data from the swim work-out. My point, do not change the work-out settings while under water. My second experience with the HRM-TRI was at a formal Olympic tri. . Garmin sent me a new HRM Pro! I already had to change the battery after less than a year. The day before I was told "Battery OK", next day dead. Neither the watch nor the phone found the HRM. I changed the battery although the multimeter told me that it wasn't completely empty. But it worked again with a new one. Here’s what I’ve done so far: (1) Verified the original issue was the battery was dead. Took out old battery, let module discharge (15min), put in new battery and verified it can connect to my Garmin Edge 520 biking computer (which it originally came with). (2) Disconnected from Garmin Edge 520 and tried to pair with Zwift via Zwift Does anyone have a bomb-proof HRM-Pro? I'm on my third unit. The other two just stopped working. With the latest firmware update (7.4), if I remove and replace the battery, the unit works for between 8-10 minutes and then stops. I can replace the battery and have it work for anyone 8-10 minutes. Anyone experiencing this? Heart Rate Monitor Replacement Strap, Heart Rate Monitor Chest Strap Replacement Band Compatible with Wahoo Tickr Polar H7 Garmin HRM Coospo - Heart Rate Monitor Strap Replacement (Powr Labs, M-XXL) 4.3 out of 5 stars 2,690 Replace battery door and four screws. After you replace the heart rate monitor battery, you may need to pair your heart rate monitor with the device again. Pairing instructions may vary from device to device. Please refer to the owner's manual for pairing instructions. For additional care instructions, see the Caring for the Heart Rate Monitor

garmin hrm pro not working after battery change