Checklist for Solving Polar Heart Rate Monitor Transmission Problems

Posted by Filed Under: Gear & Apparel, Heart Rate Monitors

polar_s625x_05_m.jpgI use the Polar 625x Running Computer – a fantastic product.

But I recently became frustrated with the heart rate monitor transmitter (the chest strap) increasingly not sending its signal to the monitor (the watch). Here are the steps you should take to fix any transmission problems you might be having:

  1. Replace the transmitter battery – a dead battery is the most frequent cause of signal transmission problems
  2. Clean the strap with warm water – specifically, clean the shiny mesh material on either side of the plastic that rests on the middle of your chestbuckled.JPG
  3. Clean the contact points – this is what solved my problemunbuckled.JPG

Following these steps will ensure your Polar heart rate monitor works (and smells!) as good as the day you bought it.

About Mark Iocchelli

Also known as the "Running Blogfather", I'm a 40-something marathoner who has beaten stress fractures and terrible shin splints. Now I'm running double the mileage with no pain - and I'm getting faster. I love to talk about running form and Arthur Lydiard. I also enjoy taking photographs, have a beautiful (and very patient!) wife, and am the proud father of two crazy kids. Feel free to contact me if you have any questions or comments about the site.

  1. Marisa on July 14th at 12:30 pm

    Timely article, Mark. I’m going through my yearly “let’s try out the HRM for a few days … oh wait, I hate that thing” phase, and one of my transmitters is totally wonky. I’m going try out your tips this afternoon!

  2. Bill Schimmel on July 17th at 8:15 am


    I had similar issues and cleaning the contact points was key for me as well. Another tip I would add is making sure those contact points get wet right before a workout. I had been wetting the strap and the contact points were sometimes not getting wet which caused transmission problems.

  3. Ryan on August 20th at 10:21 pm

    I recently ( a few months ago) started heart rate training with the NEW LEAF program and have all my workouts in my watch which has been AWESOME, as had the watch, until I started washing the strap. I had been putting it in the washer with the rest of my clothes, then it started failing. I recently sent it in to POLAR and am awaiting its return , but in the meantime, I am reduced to simply knowing aproximately where my heart rate is, and it is very frustrating. Do you think that the actual washing machine or detergents could be the probelm?

  4. Paul Butler on January 2nd at 11:43 am

    I have a cs200cad polar heart rate monitor. It worked this morning when I cycled to the gym. When I came out and ever since it has been reading between 0 and 236 rate. I have washed it and dampened the sensor area but it only makes it worse. I have reset the monitor itself. Can you help or do I need to send it back to Polar?

  5. xj on July 1st at 11:43 am

    Thank you so much for this post! I was so irritated with my HRM yesterday and paying special attention to the connectors totally helped!!

  6. Stephen Rubinkan on November 7th at 12:12 pm

    I have been totally frustrated with Polar. I first bought a Polar HRM about 10 years ago. It always worked great except for the batteries needing replacement. Last March my old one stop working and I decided to replace. I bought an FT4. This never worked properly. At low heart rate it worked, but when my pulse got above 100 the watch would loose the pulse. Also, the Polar compatible machines would also loose the pulse. I sent the watch and transmitter back 2 times, they only replace the battery saying nothing else was wrong. After this it still did the same thing. After calling Polar again they sent me an F6 with strap and when that didn’t work, an RS200, watch only. These two did the same thing. I called Polar support again, and they said that it must be the transmitter and since both transmitters are doing the same thing, they thought it must be something interfering with the transmitter. They suggest I now use my ipod, be careful with possible static electricity coming from my shirt, and to use an EKG type of gel to make sure I have good contact. I have exercised with no shirt, without my ipod, and placed an electrolyte on the transmitter. Same result. I am totally frustrated and am ready to just get my money back. I was very happy with my old watch monitor. I was very accurate and always worked, only needing new batteries after many many uses. I would like to stay with Polar since is like having it work with the treadmills and elipticals I use at the gym. Any suggestions?
    PS I have worn the watches and transmitter for hours around the house without exercising, even without moistening the transmitter pads, and it works fine.