1. Make sure the gas monitor is properly turned OFF.
  2. Remove the four screws holding the monitor together and take off the front cover. (Make sure to note the position of the sensor gasket)
  3. Carefully using your fingers only, get a firm hold on the sensor and pull it straight up and out of the monitor therefore not causing damage to the socket or sensor contact pins. Then dispose of the old sensor properly.
  4. Take the new replacement sensor, carefully aligning the contact pins with the sockets on the sensor board and press it in firmly to make proper contact.
  5. Reapply the sensor gasket into the proper position over the tops of the sensors.
  6. Once the sensor gasket is installed, replace the front cover back onto the monitor and re-install the removed screws. 
  7. Turn the monitor ON. The monitor will auto-sense there new sensor and will prompt the "SENSOR DSCVRY" screen to display. If the sensor that was replaced is the same kind as the new sensor, the monitor will start up normally and you can skip to step 9 and proceed with calibration.
  8. If the sensor installed is NOT the same as the old sensor, the monitor will auto-sense the change and will display "SENSOR CHANGE" on the screen. Then the "ACCEPT?" prompt will come up on the screen. To accept the change press the LEFT arrow button. To reject the change press the RIGHT arrow button. If the change is accepted, the user is forced to enter the monitor's password in order to complete the change. If the new sensor is installed into a socket that was before disabled on the monitor, go into the sensor setup and enable the sensor for use.
  9. Calibrate the monitor once the unit has stabilized for at least 30 minutes before trying to calibrate.

Step #8   If the unit asks for a password, the default is 672 (MSA)