I have just purchased a new Garmin HR monitor but it is behaving erratically. When not under stress the monitor starts rising sharply (over 250 BPM). It returns to normal when under stress (eg. climbing/speeding (over 35 kph)). I purchased the replacement unit because my old unit (4 years old) starting behaving in the same way. Any suggestions? PK65
A few things can cause this. Static electricity from synthetics, low air humidity, low battery in HRM, strap can start to fail which I've had happen to me.
Because it's working while under load it seems to me there's not enough moisture for the contacts to work, either because it's dry and you're not sweating much or because the strap is failing / HRM is low on battery. Try wetting the strap around the contacts, replacing the battery and if that doesn't work get the compatible Polar soft strap. It's not priced to gouge you like Garmin's and mine has lasted longer than the Garmin premium soft strap did.
