Troubleshooting for gas mixture communication errors

Diagnostic codes 724, 725, 742, 743

Diagnostic codes 724, 725, 742, and 743 occur when there is gas mixing communication error.

Symptoms

Code Symptoms XPR® models XPR action Code cancels with...
724 There is a mixing communication error on I2C1. (OptiMix™ only) All models Ramp down
  • Set process
  • Remote on-off
725 There is a mixing communication error on I2C2. (OptiMix only)
742 There is a mixing alert for I2C1. (OptiMix only) All models None
743 There is a mixing alert for I2C2. (OptiMix only)

Corrective action

  1. Examine the cable that is used to connect the gas connect console to ground:
    1. Connect the cable if it is loose or not connected.
    2. Repair or replace the cable if it has damage.
  2. Make sure that there is no damage to the ribbon cables that connect the gas mixer control Printed Circuit Board (PCB) to the flow meters.
  3. Make sure that all external panels for all system components are in position and installed correctly.
  4. Make sure that all hardware that holds the external panels is in position and is fully tightened.
  5. If the diagnostic code continues, replace the gas mixer module.

    Refer to VWI and OptiMix gas connect console mixer, transducers, and valves.