Hallmark Variable Speed 2 Stage Installation And Operation Instruction Manual page 18

Thermostat Wiring Connections
All thermostat connections are to be made on the air flow switch plate terminal strip. For ease of
installation this should be done before attaching flue piping. A jumper must be installed between the
"T-T" terminals on the oil burner.
When installing AC only a wire needs to be run from "Y/Y1" to the "O" terminal for optimum
dehumidification.
When installing AC/HP the "O" terminal is for reversing valve energized for AC operation, the "B"
terminal is for the reversing valve energized for HP operation.
When wiring for the first stage cooling choose the appropriate "Y1" terminal for the air flow required.
When installing a thermostat incorporating a humidistat it must be configured to break on high
humidity. The humidistat will cause the blower to run at 90% of the desired air flow for improved
dehumidification. A jumper wire must be installed between "R" and "H" if no humidistat is
present to dehumidify.
It is recommended to use a thermostat with an outdoor sensor to make the fuel change over from heat
pump to oil instead of a fossil fuel kit.
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