Fixing Heart Rate Monitor Problems

The Heart Rate Monitoring of Garmin watches is not as reliable as the Polar systems. The latest soft straps are better than earlier generations, but they can still be problematic. A worthwhile upgrade is to purchase a Polar Replacement Strap. The Garmin transmitter fits into the clips of the Polar strap, and you get a much better reading.

The Polar and Garmin Heart Rate Transmitters, showing the similarity in connectors.

The Polar and Garmin straps, along with the Garmin transmitter. The older Garmin strap has the connectors on the end, and is even worse than the latest Garmin strap.

The back of the various straps. You can see the Polar has absorbent electrodes that work remarkably well, where the Garmin straps use a hard plastic electrode. The Polar strap is also more comfortable than either of the Garmin straps.

The latest Polar strap has plastic surrounding the attachment clip that stops the Garmin transmitter clicking in place fully. Simply trim off the extra plastic with scissors and the Garmin will connect solidly. This picture shows the excess partly removed.

Fixing other problems

There are a number of problems you can still get with the Garmin Heart Rate Monitoring

• Make sure you dampen the strap, the electrodes and the contacts between the strap and the transmitter. Just water should work fine, though you can buy electrode gel. The Polar strap should not dry out, unlike the original Garmin strap. If you have the Garmin strap, you can always apply a little spit to wet it while on the run.
• Unlike the Polar system, the contacts on the transmitter tend to rust, so it's important to disconnect the transmitter from the strap after each use. You can see a little of the rust in the picture above.
• If you do get rust on the transmitter connecters, then a wire brush can fix the problem. I used these small brushes that worked well for me.
• A low battery can result in bad reception, and the watch does not always report a low battery condition properly.
• The straps can be damaged by washing and require careful hand washing, not machine washing. If you damage a strap, it needs replacement.
• Interference from overhead power lines used to be a problem, but the modern systems have reduced this dramatically.