Flushing, Purging and Filtering the Geothermal Loop

Flow Center Pump Maintenance and Operation

Safety Precautions

• Before performing any service or maintenance on flow center pumps, ensure all power sources are turned off to prevent electrical shock, which could lead to personal injury or death.

Importance of Water Quality

• Most failures in flow centers or pumps stem from poor water quality or debris. It is crucial to fill the system with clean water to avoid issues. High iron content, hardness, or imbalanced pH can lead to premature pump failure.

Purging Process

• When purging the system, start with a 100-micron bag filter until air bubbles are eliminated. Afterward, switch to a 1-micron bag and restart flushing for optimal results.

Valve Operations

• A 3/8 socket drive is necessary for operating three-way valves that can turn 360 degrees in either direction. Ensure valves are aligned correctly during operation to prevent air entrapment in the system.

Filling and Flushing Procedures

• Verify proper water quality before filling and flushing the system. As you fill the reservoir, alternate turning the pump on and off while monitoring water levels; do not let it drop below the intake fitting of the pump. Once stable above the outlet level, keep the pump running continuously until reaching desired levels. Turn off water supply once above T in reservoir.

Identifying Air Traps

• If there’s more than a two-inch drop in water level during operation, this indicates trapped air within the system—an essential check for ensuring efficient functioning of pumps and loops. To deadhead the pump, shut off return side ball valve on flush cart.

Antifreeze Addition Steps

• If antifreeze was not added initially when filling a loop, follow specific steps: revert both three-way tees back for flushing only; turn on pump until water level is just above outlet before shutting it off—avoid sucking air back into the system at all costs.

Maintaining Water Levels

• Adjust return line ball valve back to 'on' position as needed; adding water may be necessary to maintain levels above return tee and prevent foaming of solutions during operations involving antifreeze mixing with geothermal circuits which may take hours for complete integration—monitor antifreeze levels regularly thereafter.

Finalizing System Setup

• Set one valve open only towards loop and flush port while applying pressure through hose kit; activate flush cart pump briefly (3–5 seconds). Then isolate flow center by turning supply line ball valve off before reconnecting discharge line hose connection for extended operation (20–30 minutes). Maximum pressure should never exceed 100 psi under any circumstances when finalizing setup procedures after flushing is completed.

Seasonal Pressure Considerations

• Be aware that pressures fluctuate seasonally; they tend to be higher in winter due to heat rejection by heat pumps relaxing pipes—a critical factor when charging systems initially.

Bleeding Air from Pumps

• To remove trapped air from pumps effectively, initiate system startup while removing bleed screw located at backside of pumps—this allows any remaining air pockets within them to escape efficiently.