Boiler Performance - Nilfisk-ALTO NEPTUNE 4 FA Service Manual

Boiler performance

The symptom is reduced performance of the pump effect or the boiler effect. The symptom of reduced boiler effect is a
lower water outlet temperature than the set value. The possible causes for this are as follows:
Fault
Scale deposits in boiler tube:
Scale formation acts as insulation and
reduces heat transfer to the water.
The result is raised flue gastemperature
= increased flue gas loss.
Sooted boiler tube:
Soot has the same effect as scale depo-
sits, i.e. that they are both insulating
against the heat transfer to the water
and results in increased flue gas tempe-
rature = increased flue gas loss.
Other symptoms are that the machine
smokes during steady operation.
Low oil pressure
Full water quantity at steam stage
NEPTUNE 4 FA_EN_Ver.2.0_ 22/11
Troubleshooting
Cause
 The hardness of the water
 Air deficiency.
 Bad oil/air mixture.
 Unfinished combustion.
 Unstable ignition.
 Leaky solenoid valve on pump
Y1.
 Incorrect adjustment.
 Filter blocked, defective pump.  Replace filter/pump. Empty and
 Mechanical defect of by-pass
valve or adjustment.
Remedy
 Descale boiler tube.
 Check air adjustment and fan at-
tachment to boiler.
 Check oil pressure and oil quality.
Replace the oil nozzle. Adjust air
diffuser.
 Check bottom insulation, boiler top
gasket between tube and inner
boiler jacket in top cover.
 Check burner tube.
 Check electrodes. Adjust the air
quantity (less air).
 Check/replace solenoid valve Y1.
 Adjust pump pressure
(see page 45).
clean tank.
 Check by-pass valve.
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