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W/M Aquabalance WMB120 combi A02 code-False flame indication, HELP

andymar
andymar Member Posts: 25
in Gas Heating
My gas Weil McLain Aquabalance 120 WMB120 combi is two years old. I have been getting an A02 false flame indication error code with a hard lock out. I initially cleaned and re-installed the ignitor electrode. Problem continued. I replaced the part and again the problem persists. After re-setting the unit will operated both DHW and heat for 12 to 24 hours, cycling on and off, then go into A02 mode. Please help.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 26,005
    It's not the ignitor. The cad cell is probably seeing light when it shouldn't -- or is defective of misadjusted.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • andymar
    andymar Member Posts: 25
    Thank you for your response. I do not see a cad cell listed on any diagrams in my manual. Is it possible the cell is included in any other part? Is this something that can replaced as a homeowner without specialized tooling or gauges?
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,569
    andymar said:

    Thank you for your response. I do not see a cad cell listed on any diagrams in my manual. Is it possible the cell is included in any other part? Is this something that can replaced as a homeowner without specialized tooling or gauges?

    There isn't one on gas units,only oil
    To learn more about this professional, click here to visit their ad in Find A Contractor.

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