Hotpoint FDM550P Service Information page 10

Indesit Company
Water Turbine
This is situated at the bottom of the Air Break. Consisting of a fixed reed switch and a magnet fitted
to an impeller. Unlike previous control systems, water fill is no longer dependant on the operation of
the pressure switch. The turbine generates a series of impulses as the water rotates the impeller
vanes.
The control module translates these impulses into litres of fill water (217 impulses is equal to 1 litre
of water). The turbine also regulates the maximum amount of water that can enter the tub, therefore
acting as an overflow device.
Anti Flood Device
Consisting of a polystyrene float and microswitch. An excess of water in the base panel operates the
float switch sending a signal to the control module operating the drain pump and displaying a fault
code on the console.
Filling Sequence
1. Static Fill of 2.5 litres measured by the Fill Turbine.
2. The module checks the state of the Pressure Switch
- if Pressure Switch reaches Full Position - Move to step 3.
- if Pressure Switch at Empty Position - then Pressure Switch Fault Code displays.
3. Dynamic Fill up to 4 litres measured by Fill Turbine.
4. The module checks state of the Pressure Switch.
- if Pressure Switch Full Position reached - Programme Continues to Wash.
- if Pressure Switch at Empty Position, fills with a maximum of 5.5 litres of water measured
by Fill Turbine.
If the Pressure Switch is still in the Empty Position, the machine will drain and continues
with the cycle. No Fault Code is displayed.
The Water Level in normal conditions is almost up to the top of the filter.
Key: Static Fill = Fill with Wash Pump Off
Dynamic Fill = Fill with Wash Pump On
Detergent & Rinse Aid Dispenser
Detergent and rinse aid is automatically released during the programme.
The release mechanism is activated by means of a solenoid. This in turn operates a plunger and
lever assembly, thus releasing detergent or rinse aid as required.
The dispenser incorporates a single solenoid.
Providing the dispenser lid is closed before use:-
> The 1st time solenoid is energised the detergent lid opens (powder or tablet);
> The 2nd time solenoid is energised rinse aid is dispensed.
Note:
Rinse Aid is injected into the machine when the dispenser solenoid is energised and the
detergent lid open.
Drain Pump
This is a separate unit fixed to the sump moulding. It is operated by means of a synchronous motor
and is controlled by the control module.
Service Manual UK
10 of 35
English