Lochinvar Power-Fin 502 Installation & Operation Manual page 7

The Power-fin - How it works...
29. Flow switch
The flow switch is a safety device that ensures flow through the
heat exchanger during operation. This appliance is low mass and
should never be operated without flow. The flow switch makes
contact when flow is detected and allows the unit to operate. If
flow is discontinued during operation for any reason the flow
switch will break the control circuit and the unit will shut down.
Models 502 - 1302 Front View
Models 502 - 1302 Right Side (inside unit) - M9
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Installation & Operation Manual
(continued)
30. Drain port(s)
Location from which the heat exchanger can be drained.
31. Ventilation fan
Provides air circulation around the controls inside the unit.
32. Manual shutoff valve
Manual valve used to isolate the unit from the gas supply.
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Models 502 - 1302 Rear View
Models 502 - 1302 Left Side (inside unit) - F9
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