Polar Heart Rate Monitor Repair Battery  Changes & Trouble shooting   
  Same Day Service Normally   Directions

What to Do

The Transmitter

If the watch was working and is now blank it means that the battery needs to be changed.  For battery changes send watch and a check for $21 payable to Sark Products: Mail To:
(Repair Form Click here)  (Paper older)

(Repair Form Click here)   (PDF automated)
     info on Polar Cardiosport heart rate monitors   Feedback on new form

Sark Products
65 Helen Street
Waltham, MA 02452
(Updated 09/13/2014)
Don't call to see if this page is old
or if this is the right address  

Add $3.00 for S+H  If you send both watch and transmitter or if you include any original box that you want returned.  The battery in the polar transmitter can not be replaced.  You must exchange your old transmitter for $39  ($52 coded).  This costs about 3 cents per hour over the 2500 hour life of transmitter.  We recommend replacing with the Cardiosport transmitter.

Unless specified and paid for, monitors are returned via standard first class mail. If the package is properly addressed and has proper postage there have been no problems. If you want your monitor quicker check the price list for other options.

Additional Shipping Options
First class mail takes 3 days on average
Priority Mail  Add $4.50
Canada         Add $4.00
UPS Second Day Add $18
UPS Next Day Saver Add $27
UPS Next Day Add $29
(Repair Form Click here)
Turn around time is 24 hours. Don't forget to include a day time phone number you can be reached at in case there is a question or a problem beyond battery replacement

• Do not bend the TRANSMITTER.
• Keep the transmitter clean by washing it gently with soap and water.  Excess sweat and salt build up acts as a conductor and "shorts out" the transmitter causing unstable performance.
• Pool water with excess chlorine content and seawater may be very conductive and the electrodes of the transmitter may get short circuited, causing incorrect readings.
• Do not leave the transmitter soaking in water as this will shorten the battery life.

Check the date which is stamped on one of the eyelets.  If your transmitter is before 1998 and you have used it a lot,  we recommend that you trade it in.  Transmitter trade in, is $39 for Polar and $37 for Cardiosport. We recommend the Cardiosport because it has a changeable battery and a lifetime warranty.

(Repair Form Click here)

Packaging and shipping your monitor

Wrap the watch in one layer of thin bubble pack or in multiple layers of thin plastic.  Place watch in 5x8 inch  sturdy envelope.  The package should weigh about 2 ounces $1.08, or 3 ounces $1.28c.  If you include transmitter use a 9x12 inch envelope which will weigh a total of about 5 ounces and require $1.68 in postage.   We prefer to receive the watches in small envelopes by US Mail.  Use delivery confirmation to find out when the package is delivered.

.  They also provide tracking.
(Repair Form Click here)

heart monitor packaged in  bubble pack      Send your heart monitor to  Sark Products

Same Day Service 100%!    
repair@sarkproducts.com   Mail Us      781-647-9777
Sarkcol.gif (4101 bytes)

Why have a  repair center change your heart monitor battery

1) Leak testing, If your unit leaks corrosion will ruin your heart monitor.

2) Spare parts such as repair screws, battery holders, and gaskets. We have all these parts to ensure your heart monitor is fixed properly.

3) Heart monitor companies who claim you can change your own battery in the watch have batteries that are as difficult to change as Polar. What happens when the unit leaks and becomes full of sweat or water?  Transmitters with changeable batteries are easy to change but are suspect to leakage and the batteries do not last nearly as long as Polar. However changing a battery is a lot less money than replacing the transmitter. 

4)  We will give you a deal on a new watch if there is any question about the integrity of your unit. 

Sark Products Repair Price List. (Prices includes S & H)
(All monitors are returned via standard mail unless specified and paid for)


Watch Only  (Each additional watch add $15)
ADD $1 For  POLAR S510, S520,  S710, S720, S625, S725

Battery Change and Plastic Snap Ring Replacement for Favor, Pacer, Edge, Fitwatch

Check/payment not included with repair   (add $3 includes dealers) $23
Transmitter with elastic strap (Cardiosport or Polar) $39
Cardiosport Transmitter trade in  The battery can  be changed and it works with most older Polar models $37
Transmitter trade in  (battery can not be changed in new style Polar Transmitter) Add $18 for Coded Transmitter $39
Watch sent with transmitter to be checked or original box to be returned  (add $3.00) $24

Old Style Polar 2 piece Transmitter with 2 snaps (battery change)
Old style polar transmitter with snaps
If you have this We recommend the Cardiosport Transmitter $37

Call in without reading this page  add $2
(if you got this far you are doing good!)
International Repairs add (Add $3.00)  new.gif (147 bytes) $24
Priority Mail Return   (add $4.50 to any combo) $23

    newabc.gif (2601 bytes)

Credit Card Payment add $3.00 for shipping and handling unless repair amount unknown
Polar Elastic Strap specify T31 or old Style (click to verify) $8
Watch band for most models
Wrist strap for Favor, Old Pacer, Edge, Fitwatch                              NO LONGER AVAILABLE
Wrist Band for Favor, Pacer, Edge and Fitwatch shown.   

For watches with locked buttons, water leakage or missing digits on display call 781-647-9777 for price or send watch with credit card info and day time phone number.  You will be called with amount or opportunity to upgrade.

General Troubleshooting Tips
There are two parts to a heart monitor, the watch and the transmitter.  Both parts must work for the watch to read heart rate. It is unlikely that one of the parts works intermittently, however there are things you should be aware of.

• Make sure the transmitter is moist and held firmly against your body.  Use Electrode Gel for best results
• Be aware of possible causes of interference such as  power lines, TV, computer monitor or scanner, another heart rate monitor, traffic lights, radar, electric bus lines, car motors, motor driven exercise equipment, magnetic fields or a wireless bicycle computer.  Under must circumstances the heart monitors will work trouble free and you will learn when the interference occurs..   Place the watch near the suspected interference and see if it the heart symbol blinks  with the transmitter off your body.  Move the monitor away from the source until it is away from the interference source.
• Make sure the watch is in the heart rate mode.  This is done by pushing or holding a button or by bringing the watch close to the transmitter.  Having the watch always read heart rate would shorten the life of the battery.
• Do not press the buttons under water.
• If the heart monitor was working and the watch screen went blank, the battery needs to be changed.
• If the night light is pushed and the display dims, the battery needs to be changed.
• If there is moisture inside the watch or if the the display is compromised then the heart monitor needs repair.
•  If you can isolate the watch or transmitter you can expedite the troubleshooting process.  For instance if you are using a working transmitter and one heart rate monitor works and another one does not at the same time you can be sure the watch part is not working.  Most transmitters will work even with other brands of heart monitors.  Find a local DEALER to assist you.



Troubleshooting your Cardiosport or Polar Heart Monitor

Q: Why does the displayed heart rate jump to 240 or to 0 during the exercise?
A: It is likely that there is a source of electromagnetic interference such as power lines, TV, computer monitor or scanner, another heart rate monitor, traffic lights, radar, electric bus lines, car motors, motor driven exercise equipment, magnetic fields or a wireless bicycle computer nearby.   Place the watch near the suspected interference and see if it the heart symbol blinks  with the transmitter off your body.  Move the monitor away from the source until it is away from the interference source place the  watch as far from the interference source as possible while keeping it in range of the transmitter (30 inches).  On exercise equipment, the best place to put the heart rate monitor is to the left side.  This will keep it away from the motor and display but within the 30-36 inch distance from the transmitter.

Q: May I change the battery of the receiver myself or at a watch repair shop?
A: The receiver should be tested for water resistance using special equipment after battery replacement. Most watch repair shops do not have the equipment to do that. During the warranty period, it is necessary to service the unit at an authorized service center to keep the warranty valid. Also spare parts may be needed.

Q: The heart rate is unstable especially at the beginning of the training session. What could be the reason?
A: The electrodes in the transmitter belt must be wet when placing the transmitter on your chest. This will ensure that good contact is made. When you are done, wipe dry the transmitter belt. This will ensure a full battery life.  To test the transmitter and watch, lick your thumbs and press them against the electrodes of the transmitter.   Bring the watch in range and you will see the heart flashing on the watch.   The watch will read heart rate only when five consistent, evenly spaced heart beats are transmitted to the watch.  If the heart beats on the watch, even inconsistently, both the transmitter and watch are OK, but the heart rate will not be displayed accurately until 5 consistent readings are sent from the transmitter to the watch.  

Q: No heart rate is displayed. The watch functions of the receiver are working all right. What could be the reason?
A: The reason may be dry or dirty electrodes or the battery of the transmitter is flat. Try using the receiver with another transmitter for diagnosing whether the transmitter is the reason for the malfunction. Go to the place of purchase and ask to try another transmitter.  To test the transmitter and watch, lick your thumbs and press them against the electrodes of the transmitter.  Bring the watch in range and you will see the heart flashing on the watch.  If the heart flashes then your heart monitor will work.

Frequently Asked Questions
How should I wear the transmitter?
A: The  logo should be the right side up and the Belt should be flat against the skin.

Q: What is average heart rate?
A: The average of heart rates measured during an exercise period.

Q: What is recovery heart rate?
A: This is the heart rate that our body will decrease to after an exercise session. For example, you exercise for a 1/2 hour at 155. Two minutes after you stop exercising, your heart rate decreases to 95. The 95 would be your recovery heart rate. It is used to evaluate your fitness level after exercise. It is good to set a two minute time frame and see how many beats you recover in that time frame. Compare this recover heart rate between exercise sessions.  Make sure that during the two minutes you keep your activity consistent.  For example you will recover faster if you walk rather than jog.

Q: What is resting heart rate?
A: Resting heart rate (Resting HR) is the number of beats in one minute when you are at complete rest. Your resting heart rate indicates your basic fitness level. The more well-conditioned your body, the less effort and fewer beats per minute it takes your heart to pump blood to your body at rest.  The Polar M52 takes this a step further by estimating your VO2 Max.

Q: What is Max VO2 heart rate?
A: This is the heart rate at which you hit your maximal oxygen uptake effort. On the average, you hit your Max VO2 HR at 95% of your Max HR.

Q: What is the anaerobic threshold?
A: The physiological point during exercise at which muscles start using up more oxygen than the body can transport, i.e. muscle work produces more lactic acid/lactate than the body can process.