Alto Neptune 5, Руководство по обслуживанию, Страница: 30 / 61

5.
Trouble-shooting
Neptune_GB_Ver.2.0_10/03
The symptom is reduced performance of the pump effect or the heat exchanger effect. The
symptom of reduced heat exchanger effect is a lower water outlet temperature than the set
value. The possible causes for this are as follows:
Scale deposits in heat exchanger tube
Scale formation acts as insulation and reduces heat transfer to the water. The result is raised
flue gas temperature = increased flue gas loss.
Cause: The hardness of the water, no AntiStone or AntiStone dosing too low.
Remedy: Descale heat exchanger tube.
Sooted heat exchanger tube
Soot has the same effect as scale deposits, i.e. that they are both insulating against the heat
transfer to the water and results in increased flue gas temperature = increased flue gas loss.
Other symptoms are that the machine smokes after it is warmed up, during steady operation.
Cause 1: Air deficiency.
Remedy: Check air adjustment and fan attachment to heat exchanger.
Cause 2: Bad fuel / air mixture.
Remedy: Check fuel pressure and quality. Replace the fuel nozzle. Adjust air diffuser.
Cause 3: Unfinished combustion.
Remedy: Check bottom insulation, boiler top gasket between tube and inner heat exchanger
jacket in top cover. Check burner tube.
Cause 4: Unstable ignition.
Remedy: Check electrodes. Adjust the air quantity (less air).
Cause 5: Leaky solenoid valve on pump Y1.
Remedy: Check / replace solenoid valve Y1.
Low fuel pressure
Cause 1: Incorrect adjustment.
Remedy: Adjust pump pressure (12 bar, see page 50).
Cause 2: Filter blocked, defective pump.
Remedy: Replace filter / pump. Empty and clean tank.
Full water volume at steam stage
Cause: Mechanical defect of by-pass valve or adjustment.
Remedy: Check by-pass valve.
28.
Heat exchanger performance