Pump Disassembly; Pump Reassembly - Pentair WHISPERFLO VS Installation And User Manual

16
Refer to the Motor/Hydraulics Assembly Diagram, on the next page, for a parts breakdown of the pump.
Always disconnect power to the pump at the circuit breaker before servicing the pump. Failure to do so could result in death or serious
injury to service people, users or others due to electric shock. Read all servicing instructions before servicing the pump.
DO NOT open the strainer pot if pump fails to prime or if pump has been operating without water in the strainer pot. Pumps operated in
these circumstances may experience a build up of vapor pressure and may contain scalding hot water. Opening the pump may cause
serious personal injury. In order to avoid the possibility of personal injury, make sure the suction and discharge valves are open and strainer pot temperature
is cool to touch, then open with extreme caution.

Pump Disassembly

TOOLS REQUIRED:
• 1/4 in. hex key wrench
• 3/32 in. hex-head wrench or socket
• 9/16 in. open-end wrench or socket
• Adjustable wrench
• #2 Phillips screwdriver
• Flat blade screwdriver
TO DISASSEMBLE THE PUMP:
1. Press Start/Stop to stop the pump and disconnect
all power to the pump at the circuit breaker.
2. Disconnect any digital inputs or communication
cables from the pump (if connected).
3. Close all valves in suction and discharge lines.
4. Relieve all system pressure at the filter's air relief
valve.
5. Remove both drain plugs from the bottom of the
strainer pot.
6. Using a 9/16 in. open-end wrench/socket and an
adjustable wrench, remove the two strainer pot
through-bolts and nuts securing the motor/hydraulics
assembly to the strainer pot.
7. Using a 9/16 in. open-end wrench or socket, remove
the four remaining strainer pot bolts.
8. GENTLY separate the motor/hydraulics assembly
from the strainer pot.
9. Using a 3/32 in. hex-head wrench, remove the
two screws securing the diffuser to the seal plate.
Remove the diffuser.
10. Using a 1/4 in. hex-head wrench, hold the motor
shaft in place at the rear of the motor. This will
prevent the motor shaft from spinning while removing
the impeller and impeller screw.
11. Continue to hold the motor shaft in place. Remove
the impeller screw and washer clockwise using a #2
Phillips screwdriver.
12. Remove the impeller counter-clockwise by hand.
13. Using a 9/16 in. wrench, remove the four (4) bolts
securing the seal plate to the motor.
14. Remove the seal plate from the motor/drive
assembly.
15. If replacing the shaft seal, continue to Shaft Seal
Replacement on page 17.
Otherwise, continue to Pump Reassembly when
necessary.
WHISPERFLO VS and WHISPERFLO
®
VST Variable Speed Pump Installation and User's Guide
®

Pump Reassembly

1. Place the seal plate onto the motor assembly,
ensuring the side marked "UP" is at the top.
2. Using a 9/16 in. wrench, reinstall the motor/sealplate
Bolts in a criss-cross pattern the seal plate to the
motor with the four motor bolts.
Tighten to 70-80 in-lbs. (81-92 kg/cm).
3. Using a 1/4 in. hex-head wrench, hold the motor
shaft in place at the rear of the motor. This will
prevent the motor shaft from spinning while
reinstalling the impeller and impeller screw.
4. Continue to hold the motor shaft in place and
reinstall the impeller onto the motor shaft clockwise
hand tight.
5. Continue to hold the motor shaft in place and
reinstall the impeller screw and washer.
Tighten to 25 in-lbs. (29 kg/cm).
Note: The impeller screw is reverse threaded and
tightens counter-clockwise.
6. Reinstall the diffuser onto the seal plate using the
two diffuser screws.
7. Inspect the diffuser seal and seal plate gasket for
damage and replace if necessary.
Grease both before continuing.
8. Using a 9/16 in. open-end wrench/socket and an
adjustable wrench, secure the strainer pot to the
motor/hydraulics assembly with the six strainer pot
bolts and washers.
Note: Do not tighten the two through-bolts until all
six bolts are in place and finger tightened. Tighten
in a criss-cross pattern to 110 in-lbs (127 kg/cm).
Note: Ensure the seal plate gasket is not pinched
between the strainer pot and motor assembly.
9. Reinstall the both drain plugs into the bottom of the
strainer pot.
10. To restart the pump, continue to Restarting the
Pump, page 18.