Troubleshooting
Pumping system troubleshooting
Symptom
Cause
Remedy
There is no circulation
Air-bound system
Vent the system
The impeller or piping is clogged.
Locate and remove the obstruction.
The system valve is closed.
Open
The electrical circuit for the pump is
broken.
Check all related low and line voltage
circuits.
There is inadequate circulation.
Air-bound system
Vent the system.
The impeller or piping is clogged.
Locate and remove the obstruction.
The impeller is damaged.
Replace pump.
The pump is too small.
Replace the pump if single speed. If
three speed switch to higher setting.
Partially air-bound pump
Vent the pump casing.
Improper motor speed
Check the wiring and the voltage.
There is pump or system noise.
Entrained air
Vent the system.
Pump cavitation
Lower the pump or raise pressure or
relocate (see note below).
Excessive water velocity
Install balancing cocks or parallel
piping.
Pipe vibration
Provide adequate pipe support.
There is premature failure of pump
components.
Improper pump (size/type)
Replace
Improper pump location
Relocate
Excessive water treatment
Check the manufacturer’s
instructions.
Pump operating close to or beyond
the end point of curve.
Balance the system.
Excessive piping load
Provide proper pipe support
Troubleshooting
NRF
™
-25,36,45/NBF
™
-25,36, and 45 Circulator Installation, Operation, and Maintenance Manual
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