MACH® Series | Maintenance |
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5.5.2 Auto-reset Service Codes
Code | Lockout |
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b 08 | Air pressure switch open. |
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b 18 | Outlet high limit temp. |
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b 19 | Return high limit temp. |
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b 24 | Switched inlet / outlet. |
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b 25 | Outlet temp rapid change. |
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b 26 | High exhaust back pressure. |
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b 30 | Max delta T. |
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b 40 | Flue sensor open. |
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b 52 | High flue temp. |
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b 61 | Air pressure switch closed. |
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b 65 | Fan speed incorrect. |
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Description
The air pressure switch failed to close to indicate sufficient air flow to start the boiler. The outlet water temperature has exceeded the internal high limit temperature setting. The return water temperature has exceeded the internal high limit temperature setting.
The inlet water temperature has been more than 18° F above the outlet for more than 75 seconds.
The outlet water temperature is increasing too fast. Indicating low flow condition.
The high exhaust back pressure switch is tripped indicating a blocked stack, inlet, or condensate system.
The temperature rise across the heat exchanger is greater than maximum allowed, indicating insufficient flow.
The flue gas temperature sensor is indicating an open circuit.
The flue temperature has exceeded the maximum allowable setting. The air pressure switch failed to open prior to starting the blower. The fan is being directed to a higher speed than it is achieving.
WARNING
If any “Manual Reset” limit device trips,
DO NOT
reset without determining and correcting the cause.
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