York HP Series Service Manual page 17

 A ventilation motor (provided by the installer) can be installed inside the fresh air duct to improve
the fresh air volume. There are reserved ports for this motor on main PCB (Standard for 3D
inverter units, and only optional for DC inverter 53~160 units).
2.3.3.8.Drain pump (Optional)
 Built-in drain pump can lift the water to 750mm upmost, which widens the drainage piping range.
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