A.O. Smith Water Heater 520 Direct Vent Indoor Service Manual page 90

CONFIDENTIAL
520 Indoor / 520 Outdoor Service Manual
Ver. 1.00
Computer board assembly
Other than Part# 719,
the 520 Indoor and the
520 Outdoor share the
same components. The
520 Outdoor doesn't
have the exhaust
thermistor assembly
(No.706) and the
exhaust fan motor wire
(No.720).
Burner assembly
The 520 Indoor and Outdoor share the same components.
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