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Blood Pressure Monitors

Customer Support > FAQ/Troubleshooting

Frequently asked questions about blood pressure and blood pressure monitors:

General Questions:

My blood pressure monitor shows readings with a decimal point:
If your BP monitor shows readings like "18.0" this means that it is in kpa mode instead of mmHg mode. To change this, please follow the following steps depending on the model:


  • Turn the BP monitor off (blank display)
  • Push the memory button and keep it pushed until 0.0 appears on the display. Release the mem button
  • Push the mem button one more time and 0.0 changes to 0
  • Push the START/STOP button to turn the monitor off.

Readings are now displayed in mmHg mode again.


  • Turn the BP monitor off (blank display)
  • Push the mode butten a couple of times until 0.0 is displayed in large numbers.
  • Push the mem button one more time and 0.0 changes to 0
  • Push the START/STOP button to turn the monitor off.

Readings are now displayed in mmHg mode again.

What batteries do I use?
All Zewa upper arm units use 4 x AA type batteries.
All Zewa wrist units use 2 x AAA type batteries.

How long do the batteries last?
This depends on several factors. The 2 main factors are:

  • High blood pressure. The higher the pressure the more the machine has to inflate, therefore using more power.
  • The bigger the cuff the more the machine has to pump, therefore using more power.

Why does my machine not pump to 200?
Our blood pressure monitors use a system called . This means that the machine will only inflate as much as necessary to take a reading. 200 was a limit used by older generation units and is also used in manual and semi automatic units.

Upper Arm Blood Pressure Monitors:

What cuff size do I use on my upper arm monitor?
It is very important that you use the correct cuff size. Before deciding which cuff is correct for you, measure your circumference of your upper arm. Let your arm hang at your side and measure the circumference in between your shoulder and your elbow.

Why do my blood pressure readings vary so much?
Your blood pressure changes constantly. To read more about blood pressure please check our health information section.

My blood pressure readings are CONSTANTLY too high or too low:
Make sure you are using the correct cuff size. Also, make sure you have the correct posture when taking a reading. Sit in a chair with both feet on the floor. Place your arm in your lap and relax for 5 minutes before taking a reading.

Are cuffs interchangeable between manufacturers?
No, every manufacturer uses different plugs to connect the cuff to the unit. Also, BP machines use a motor specifically developed for a certain machine. If the cuff is too large or small the motor may not be able to inflate the cuff.

Can I use a Zewa upper arm monitor on the forearm if the cuff does not fit?
No, these machines have not been tested and calibrated for usage on the forearm.

Should I use the right or left arm?
Zewa’s monitors can be used on any arm, however it is easier to apply the cuff on the left arm. Also, readings will vary from one arm to the other, therefore don’t switch arms and compare the readings, they will vary. If using the left arm, stay with the left arm.

When using the AC Adaptor, do I have to remove the batteries?
No, you don’t have to remove the batteries, but we recommend it. Most people who use the AC adaptor forget that they have batteries in the unit and they may leak if left in the unit for too long. This leakage may damage the device.

Wrist blood pressure monitors:

I receive unusually high or low readings on my wrist blood pressure monitor?
Make sure that the wrist blood pressure monitor is at the same level as your heart. Refer to the instruction manual on how to use a wrist unit.

Error Codes:

Error Codes are mostly related to air leaks in the cuff or BP monitor.

How to detect an air leak (most error codes):
If your blood pressure monitor starts pumping, but does not fully inflate before showing an error code the cuff or BP monitor is leaking air. Normally the number shown on the display will stop at a certain point, for examply 54, while the BP monitor still pumps, but it will not pump higher than that number and than shows an error. This indicates an air leak.

How do I determine if the leak is in the cuff or the BP monitor?

If the cuff is leaking air you will hear a hissing sound coming from the cuff. Depending on the size of the leak, it can be easier or harder to hear. In this case the cuff needs to be replace. If the cuff is not under warranty, please call Zewa customer service at 1-888-993-3592 to purchase a new cuff.

BP Monitor:
If you can not hear any sound from the cuff than the air leak is inside the BP monitor. In this case you will have to send the BP monitor to our service department to be checked. For service information please click here.

If you are not sure where the problem is, please call our customer service at 1-888-993-3592.

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