MH Series Horizontal Multi-stage Pump
11
1. Set the pump upright on end and rest it on the motor.
2. Remove the 8 socket-headed screws that hold wet end to the flange.
3. Pull the pump casing away from the flange and remove the last stage cover and set aside.
4. Remove the O-ring.
5. While securing the motor shaft so it does not rotate, unthread the pump shaft from the
motor shaft.
6. Pull the hydraulic assembly away from the motor and flange.
7. Remove the mechanical shaft seal. (If you need to remove the stationary portion of the shaft
seal, complete Step 8 first and then push the piece out from the back side of the seal plate.
Seal plate can be removed without adapter flanges.
8. Remove the 4 bolts that hold the motor to the flange and pull the flange away from
the motor.
MH Series Troubleshooting Guide
Problem
Possible Cause
Corrective Action
Pump does not deliver water or
pressure
1. The pump is fully primed.
1. Stop the pump, fill it with water, check all pipe
connections to make sure there are no air leaks and
try again.
Low pressure
1. The motor is not up to speed.
2. The impeller is partially plugged.
3. Air is leaking into suction line.
1. Check for proper voltage and tight wiring connections.
2. Check impeller for rocks or debris. Refer to
disassembly instruction for getting to impeller.
3. Check suction line connections.
Low capacity
1. Your water level is deeper than 10 feet.
2. You are using too long a pipe from the water to the pump.
3. You have a plugged impeller.
4. The pipe from the pump to the water is partially plugged.
1. Pump can’t pump below 10 feet. Call your Franklin
Electric dealer.
2. Use a larger diameter pipe.
3. Check impeller. Refer to disassembly instructions
above.
4. Check pipe.
Motor overheats
1. Improper voltage or wiring connections.
2. Improper ventilation for the motor.
1. Check to see if your voltage is the same as indicated
on the motor name on dataplate. Be sure all wiring
connections are tight.
2. Check to see if motor is clean and properly vented.
Loss of pressure when no water
is used
1. Leaks in piping or valves.
2. Water level drops below the end of the pipe.
1. Check connections.
2. Pump is out-producing the well. Close down control
valve gradually until pump starts operating properly.
Motor will not start
1. Open switches, blown fuses or loose connections.
2. Improper connections to motor.
1. Check switches, fuses, and connection.
2. Make sure connections are tight.
Air logging (excessive air in pipe)
1. Air leaks in pipe.
2. Water drops below the end of the pipe.
1. Check connections.
2. Pump is out-producing well. Tighten down control valve
gradually until pump starts operating properly.
Gravelly noises inside
pump (cavitation)
1. Water level is below 10 feet.
2. Suction pipe is too small or length of pipe is too long.
3. End of suction pipe is in mud or sand.
1. Call your Franklin Electric dealer.
2. Use a larger diameter pipe.
3. Raise end of suction pipe or clean out well.
