How to Change the Pressure Switch on a Ducane Heat Pump

Opening the Heat Pump Cabinet

• For safety, turn off the Ducane at the indoor thermostat and switch off the circuit breaker. When the metal cabinet for the heat return cools completely, remove the service panel on the side of the heat return, using a screwdriver. Place the screws in a safe location and set the panel on the floor, out of the way.

Locating and Removing the Pressure Switch

• The pressure switch in a Ducane heat pump is mounted near the top. It is easily recognizable by the flexible plastic tube that attaches from the switch to the pipe on the blower motor at the bottom of the Ducane. Pull off the tube at both ends and blow through it to confirm it is not clogged. Remove clogs by holding the nozzle on a can of compressed air to one end of the tube and blowing through it. To remove the pressure switch, slide off the wires connected to the switch contacts and extract the screws holding the part to the inside of the Ducane.

Installing the New Switch

• Secure the new part in the same position as the old switch and secure it with the screws. Push on the tube firmly at both ends, both to the blower motor and to the small pipe on the pressure switch. Once the switch is secure, slip the Y-shaped clips on the wires onto the contacts on the new switch.

Closing the Ducane

• Verify all wiring is completely inside the cabinet before placing the service panel on the side and attaching it with screws. Switch on the circuit breaker to restore power to the Ducane, which can now be activated at the wall thermostat.