Errors

• - select type -
• Challanger Solo CC50s
• Challenger CC85
• Challenger Combi CC105
• Challenger Combi CC125H
• Challenger Solo CC105s
• Challenger Solo CC125Hs
• Challenger Solo CC150s
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• Keystone KS 1000
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• MARQUIS TWH200
• MARQUIS TWH200LP
• Prestige ACVMax 110
• Prestige ACVMax 155
• Prestige ACVMax 175
• Prestige ACVMax 250
• Prestige ACVMax 299
• Prestige ACVMax 399
• Prestige ACVMax Excellence PTE 110
• Prestige ACVMax80
• Prestige Trimax110 Solo
• Prestige Trimax175 Solo
• Prestige Trimax250 Solo
• Prestige Trimax399 Solo
• Prestige Trimax60 Solo

• - select code -
• 11
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• 20
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• 61
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• 72
• 73
• 76
• 94

Boiler type MARQUIS TWH200

Error code 20

Cause:

High Limit Overheat Switch – Closed is Normal, Open is Fault

Solution:

Press the Power button to clear the Error Code.
1. Inspect the High Limit Overheat switch. Ensure proper connections.
2. Check High Limit Overheat switch resistance. If resistance is zero, replace the switch.
3. If the problem persists, replace the main control.