The Error Code 004 on blood pressure monitor is usually an indication that there is a pneumatic leak in the system or the cuff is too loose during inflation. The resolution is usually to put on the cuff a little more snugly so that you can insert 2 fingers between your arm and the cuff.
If you still get the error 004 after making these corrections, you may have a system leakage in the cuff or the hose or connectors. Your cuff may need to be replaced. If you bought it from any of our distributors, you may want to call them for the replacement. If you bought it directly from the iHealth website, please email support@ihealthlabs.com with the order number and we can check if you are still within the warranty period.