I have two Ironman Triathlon Timexes.

The watch and the sensor just cannot get their acts together.

Both of them gave a lot of trouble, and I read the reviews here that said I was not alone.

I hope this is of some help to a few people.

Firstly I changed the strap battery, but made little or no difference.

Although the watch worked as a watch, I figured that since these things are digitally encoded, and this takes power, I had the watch battery changed.

That has made a huge difference. The watch picks up the sensor almost instantly. It still shows 30 BPM, but within a minute at the most it comes up to correct readings.

HTH someone It's a bit of a PO that I had to go to all this trouble and spend quite a bit of money on a new watch. But at least I am not having a "fight" with it every time I go out.