Primary Sensor (Ch Ntc); Overheat Thermostat; Flue Overheat Thermostat (With Grommet) - Worcester GREENSTAR Ri Installation And Servicing Instructions

SERVICE AND SPARES
6.8.2

PRIMARY SENSOR (CH NTC)

To gain access to the following components
the outer case has to be removed:
B Primary sensor
B Overheat thermostat
B Flue limit thermostat
Refer to figure 72 for removal.
1. Remove electrical connection by pulling upwards.
Squeeze retaining clip on plastic moulding of sensor
and pull back and up until clear of pocket in heat
exchanger.
2. Pull forward to remove completely.
B Coat new sensor with heat conductive paste and
replace.
6.8.3

OVERHEAT THERMOSTAT

Refer to figure 72 for removal.
B Remove two electrical connectors from thermostat.
3. Slacken and remove fixing screw and thermostat (3).
B When replacing ensure thermostat sits correctly on
surface of the casting with the left hand side of
thermostat sitting up against the shoulder.
It is essential that the mating surface of the
thermostat is coated with heat conductive
paste.
2.
1.
Fig. 72 Primary sensor and overheat thermostat
50
6.8.4
To remove and replace the thermostat either:
B Using a small terminal screwdriver, prise the
-or-
1. Release the flue connection from the sump.
2. Push the flue tube up.
Fig. 73 Lower exhaust section
B Remove electrical connections.
1. Push the flue limit thermostat in from the sump.
B Retrieve the thermostat from the sump well.
3.
Fig. 74 Remove thermostat
To replace, push the thermostat and new grommet
gently back into the opening until contact with the
locating ridge is felt.
FLUE OVERHEAT THERMOSTAT
(WITH GROMMET)
thermostat and grommet from the plastic housing.
Take care not to damage the plastic housing.
1.
2.
1.
6 720 644 744a (2010/10)