c. Black: This goes to the 24vac COMMON terminal of the HVAC unit transformer, NOT the transformer powering the zoning equipment. This terminal is usually NOT present on the zone control board under “equipment” since it is not needed. If your old thermostat has a “C” for common, that is the 24vac common terminal you are looking for. If replacing an older pump, connect the black wire to the same location as the original black wire.
d. NOTE: Very old pumps may be 110vac and your new EP-1 or EP-2 pump is NOT wired like the original pump.
OPERATION: A relay is energized to start the pump on either call for fan or heat. The pump will not run if the equipment is not running.
3. After installation, wrap relay and connections with electrical tape to avoid shorting.
4. Hoses:
- Vacuum: The top hose is the vacuum connection which corresponds to the larger connector that is attached to the side of the EP-1 pump. Disconnect the larger tubing where it plugs into the larger left side fitting of the solenoid panel. NOTE: You may need to slightly stretch the smaller size 3/16” ID tubing to fit over the original 1/4” vacuum elbow connector.
- Pressure: The bottom hose is the pressure connection. Disconnect the smaller original 3/16” ID tubing from the smaller left side fitting of the solenoid panel, and connect the bottom hose here.
5. Mounting the pump: Use 2 long deck type screws to suspend the EP-2 pump far enough away from the wall, if possible, so that the pump and sling do not touch the wall. This will keep potential noise from wall contact from occurring.
