Cleaning the Strainer Basket

The strainer basket captures larger debris from the pool return prior to the main pump. It is located in the lower level (gallery) of the pump house. The strainer basket should be inspected regularly. Cleaning is necessary when it becomes clogged.

Beyond visual inspection, a low flow rate (i.e. less than 570 GPM - the required rate for proper turn-over) along with nominal to low filter tank pressures indicates cleaning may be necessary.

Procedure

Preparation

1. Disable the call for heat by lowering the temperature setpoint on the temperature controller to a value several degrees below the sensed temperature (in the future, a switch may be added to do this).
2. If the boiler was operating in Step #1, wait for the boiler circulation pump to stop. This may take several minutes. Observe that during this period, the manifold temperature will drop, approaching the boiler inlet (sensed) temperature. It is important to allow the boiler to complete a proper cool-down prior to cutting water circulation. Failure to do so could result in an over-temperature trip, or damage to the boiler itself.
3. Stop the main pump motor. Switching off the disconnect (the lever on the enclosure above the motor starter) may be necessary in some cases (see below).
4. Close the water valves on both sides of the strainer basket. If water overflows, additional closing force may be required (the valves should form a complete seal).

NOTE: Prior instructions included disabling the chlorinator and acid pump. This is not necessary; the flow meter on the Chemtrol bypass line automatically disables all chemical feeds when the pump is stopped.

Cleaning

1. Loosen the six screws on the strainer lid.
2. Remove the strainer lid.
3. Remove the strainer basket.
4. Inspect and clean the basket. Discard the contents into a garbage bag.
5. In some cases, debris may pass through the strainer and clog the pump. Non-typical noise, vibration and/or reduced flow (despite cleaning/backwash) may be indicative of a clogged pump. If this is determined to be the case, ensure that the main pump motor disconnect is switched to the off position. A lock-out procedure may be required. Once the motor is safely disabled, reach into the pump and clear of all debris.

Wrap-Up and Observations

1. Return the strainer basket to the base. The taller side of the basket must be on the right (pump) side.
2. Re-install the strainer lid. Ensure the seal is clear of debris. Hand-tighten the six screws.
3. Open the water valves on both sides of the strainer basket. In some cases, the valve on the output side of the pump may need to be partially closed (such as low water level in the surge tank).
4. Hand tighten the six screws again, as needed.
5. Start the pump motor.
6. Open the air bleed valve above the Boiler Low Water Cutoff next to the boiler. If tripped, reset.
7. Return the temperature controller setpoint to the nominal value (i.e. 82 °F).
8. Bleed air from the filter tanks after several minutes of operation.
9. Adjust the output flow of the pump to be within 600 to 650 GPM. The flow rate must exceed the required minimum (570 GPM with some margin) but not grossly exceed the combined maximum flow rate of the sand filters (560 GPM). Note that 560 GPM is not a typo; refer to Sand Filters for discussion on this discrepancy.

Observe the water in the strainer some period of time after the pump has resumed operation. The water level should be near the top, with minimal turbulence. If there is a significant amount of turbulence, air is likely being pulled in through the seal and entering the system. The screws must be further tightened. Otherwise, operation of the boiler and sensor probes may be negatively affected.

Other Considerations

During the cleaning process, the Chemtrol sensor probes may no longer be in contact with water. If possible, shut off the bypass line outflow valve prior to stopping the main pump motor. This will keep the sensors submerged. Otherwise, be sure to minimize the amount of time the sensors are out of water, as they may be damaged if allowed to dry out.

Please keep the lower level (gallery) clean! Avoid leaving debris on the floor or in buckets. Periodic vacuuming is encouraged. Avoid allowing significant debris to enter the drain, as it may clog the pipe.

To start or stop the pump, press the black START or red STOP button on the Pump Motor Starter.