Heart rate monitor not working

Check the battery or batteries you put into the monitor. I suspect you'll need to do that part again.

I would go to Polar for a definitive answer but your monitor may not be making a good contact with your body. Therefore the reception of your heart beat is constantly starting over and can't give a reading fast enough. Try adjusting how you wear the monitor and see if it makes a difference. There is a battery in the chest strap also. The new ones have to go to Polar to get replaced unfortunately. That is another possibility.

Honestly, I would contact Polar at this link:

Good luck.

http://www.polarusa.com/us-en/support/product_support

Hi,
Here is the manual for your heart rate monitor:
http://www.omronhealthcare.com/img/shop/hr-100c---2003-hr100cinst-rev-a.pdf
The size of your wrist shouldn't matter, because you can actually mount the monitor to a bike handle, so you don't have to be wearing it at all. It's just acting as a receiver, displaying the info. Are you wearing the transmitter belt, is it positioned correctly, and tight enough? Are you putting water or gel on the backside of the transmitter so that you get good conduction and contact? Is the transmitter belt within 20 inches of the monitor receiver display?
The transmitter battery might be low. If so, the symptom would be that your readings can be erratic. I know you said that you just bought it, but batteries can be low in new products. ..How many times have you bought a new digital watch only to find that it had a low battery...You can replace the battery in the transmitter with a lithium 3v battery #CR2032. Do you see a low battery indicator? If so, the display (receiver) battery also needs replacing and it uses the same battery as the transmitter.
Hope it helps, please let me know.
Thanks

Click on my profile (escapement), then click on Tips and Tricks. There you will find link to all POLAR watch manuals. Rate me, please.

You should have someone who is use to servicing heart rate monitors take a look at it. There are parts in the monitor that can corrode and would need to be cleaned. Also, look into replacing the battery in both units (Strap and wrist) and make sure the unit is reset properly.

try this link for the manual.
polar f11 heart rate monitor manual Google Search .
However, you may wish to reset the unit and start over with new settings. You can resetyour Polar F11 by following a few easy steps. Press any button to activate the Polar F11 Fitness heart monitor unit. Press all buttons on the Polar F11 Fitness heart monitor simultaneously, except the "Light" button.

How to Reset a Polar F11 ' Healthfully

https://healthfully.com/reset-polar-f11-7176556.html reset polar f11 heart rate monitor Google Search

to shutoff HR out of range alarm - when selecting the ranges in the HRM Steup mode - press the START/SPLIT button to toggle the alarm on and off. (use the start/stop button on the pro fitness model). page 14 in my manual

I Have had the same problem couple of times (and forgotten each time how I solved it). I figured it out just now and this is what I did.

1) turn on unit and put on heart monitor (make sure battery is good and wet heart strap)
2) using the mode button navigate the menus to: Settings: General: Accessories: Heart Rate Monitor
3) Once in the Heart Rate Monitor option make sure "Yes" is selected and then use the arrow buttons to highlight "Restart Scan" . Press the enter button to rescan for your heart monitor. (I had to rescan twice)
Go back to the main monitor screen to see if you are recieving heart rate signals.

I am not sure why a manual rescan needs to be done every time but it would be nice if Garmin fixed this issues in a unit software update (my unit has software version 2.80)

Here are the things I have noticed that help:
- enough moisture between the HR monitor and your chest. Apply water right before your workout to make sure it isn't all dry between the time you put on your monitor and when you actually started your workout.
- Make sure the strap is tight enough. Mine gets loose over time and the bouncing of running will give me inaccurate readings until I tighten it up again. You can test if this is the problem by using your hands to press the monitor more tightly against your chest - if that seems to fix the problem that a loose strap could be it.
- Use a "conductive gel" instead of water between the monitor and your chest. Conductive gels are pretty cheap.