elco Minifill-E - Fault Finding; Controls Schematic

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13.0 Fault Finding
Fault Finding
Fault Possible Cause Action
Pump will not run • Unit up to pressure
• No power to unit
• Isolator fuse blown
• Cut in pressure set incorrectly
• Pump seized or faulty
• None
• Check at source
• Replace fuse. Note – investigate the cause of the blown fuse
• Adjust cut in pressure
• Service or replace pump
Pump runs but will
not build up
pressure
• Pump isolating valve closed
• Pump not primed
• Float switch faulty
• Pump non return valve jammed
• Blocked flow restrictor
• Open valve
• Prime pump
• Check water level and replace float switch
• Check valve
• Check flow restrictor for blockage
Pump cuts in & out
rapidly
• Value of cut in and cold fill pressure set
incorrectly
• Non return valve not sealing correctly
• System leak
• Adjust values
• Clean valve seat or replace valve if necessary
• Trace leak and ensure system is sound
Pump runs
continuously
• Value of cold fill pressure set incorrectly
• Pump relay faulty
• System leak
• Adjust value
• Replace faulty relay pcb in grey box
• Trace leak and ensure system is sound
Pump cuts out at
wrong pressure
• Pressure gauge is inaccurate
• Internal pressure sensor faulty
• Replace pressure gauge
• Replace pressure sensor
Maximum system
working pressure is
too high
• Cold fill pressure set incorrectly
• Internal pressure sensor faulty
• Adjust value
• Replace pressure sensor
Boiler switches off
unexpectedly
• Hi or Lo pressure alarms set incorrectly
• Safety circuit is wired incorrectly
• Adjust values
• Check wiring against wiring diagram
System pressure
runs consistently at
cold fill pressure
• Small system leak
• Trace leak and ensure system is sound
Figure 12 – Controls Schematic
COLD WATER
INLET
OVERFLOW
BALL VALVE
LOW LEVEL ALARM
ISOLATING VALVE
NON
RETURN
VALVE
PUMP
0.7HP
2.8A
PRESSURE
SENSOR
PRESSURISATION UNIT
TO SYSTEM