Tomtom GPS watch + HRM + Music

If the LEDs are not lighting up and you are getting a "--" symbol instead of the actual HR it means the device has failed. Call Support for a replacement. To get the number for Customer Support, select Contact Us at the bottom of this page, select the service required and the product name and click Contact Customer Care and then Phone Us. It will give you the phone number for the country your account is registered under (this can be changed by clicking the flag icon in the bottom right corner of the screen).

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gaz47 wrote:

Thanks for your reply, but no the green led still flashes, the heart rate is very inaccurate. eg when at full tilt in cycle mode, actual heart rate is 140 - 160 bpm measured by Polar HRM, but Tomtom registers 72 - 76 bpm. This inaccuracy has been erratic for a few weeks, mid ride the indicated HR drops back to 72 - 76 bpm, then later it will come back to life and register very close to my Polar HRM. Very disappointed

What you are seeing is a common issue with wrist based HR sensors. There are two issues around heart rate using optical HR monitors, and these are on all devices, not just TT ones: low heart rate and HR spikes. Low HR is often seen in rowing, cycling and weight lifting. Any time you do an activity that squeezes or tenses the forearms (like the pull stroke in rowing, bearing down on your handlebars in cycling, or virtually any weight lifting move) you are squeezing the blood vessels the watch is reading, so it sees this as a reduced pulse. It is not that the watch is having a problem reading your pulse; it is that your pulse at the wrist has actually dropped because you are temporarily cutting off blood flow to the vessels it is reading. I have experienced this with every optical HR I have used, including a Mio and a Scosche unit. For these sorts of activities you are better off using a chest strap synced to the watch if getting a more exact reading is important to you (which is what you are seeing with the Polar model). There is nothing wrong with the watch itself, it is a limit of the technology.

I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question.

gaz47 wrote:

If this is a common issue as you say, then I want my money back. If TT is selling a product with known limitations, they have fallen foul of consumer law in Australia. I will be returning my watch for a refund.
Thank you for your interest and frank comments.
Regards Gaz

When you are pressing down on the handlebars you are cutting off the blood flow to your wrists so it is accurately reading your pulse, which is simply lower at the wrists than at the heart. It is not an issue with the device, it is an issue with human physiology and I am not sure consumer law covers that.