Technical data

Sightglass
Remove the inner case cover. Unscrew the two screws and
remove the assembly. Fit a new gasket when fitting the new
assembly. Refer to Fig.26 and 27.
Central Heating Flow Temperature Sensor
Drain the appliance. Remove the inner case cover. Unplug the
electrical connection, orange leads.
Remove the clip and cable tie and pull-out the sensor. Refer to
Fig.14.
Fit a new cable tie to secure the clip.
Refill, vent and re-pressurise the appliance. Prime the siphon.
Overheat Thermostat Sensor
Remove the inner case cover. Pull off the connections, red leads.
Unscrew and remove the sensor. Refer to Fig.14.
Flue Temperature Limiter
Remove the inner case cover and the control module. Pull off the
connections, red leads. Unscrew and remove the sensor. Refer to
Fig.14.
Domestic Hot Water Inlet Temperature Sensor
Lower the facia. Drain and remove the siphon.
Pull off the connections, grey leads. Remove the clip and pull out
the sensor. Refer to Fig.14. NOTE: The sensor probe is
approximately 150mm long. A small quantity of water will be
released.
Prime the siphon.
Domestic Hot Water Outlet Temperature Sensor
Lower the facia. Drain and remove the siphon.
Pull off the connections, orange leads. Remove the clip and pull
out the sensor. Refer to Fig.14. A small quantity of water will be
released.
Prime the siphon.
Manual Air Vent
Drain the appliance. Pull off the tube and unscrew the insert
from the body. Refer to Fig.15.
Refill, vent and re-pressurise the appliance. Prime the siphon.
Expansion Vessel
Drain the appliance. Remove the inner case cover.
Remove the control module.
Release the union connection at the base of the expansion
vessel. Unscrew the two screws fixing the vessel. Refer to Fig.14.
In the unlikely event of a failure of the expansion vessel, it is
acceptable to fit a replacement vessel of a similar (10 litre) or
greater capacity external to the appliance but as close as
possible in the CH return pipe.
Flow Switch
Drain the dhw circuit by closing the mains water valve and
opening adjacent tap below the level of the appliance. Lower the
facia. Pull off the electrical connection from the flow switch.
From beneath the appliance undo the inlet and outlet water
connections and remove the switch. Refer to Fig.29.
Transfer the Venturi to the new switch (if not already fitted) -push
fully home.
NOTE: The inlet water filter is in the flow switch. Refer to Fig.30.
If there is insufficient access from beneath then it will be
necessary to remove the pump, diverter valve and heating return
pipe to gain access to the flow switch.
Refill, vent and re-pressurise the appliance. Prime the siphon.
26
Fig. 27. Sightglass.
Inspection
glass
Fixing
screws
Gasket
Gasket
Frame
Fig. 28. DHW Inlet and flow temperature
sensor.
Heat Store
Outlet
Temperature
Sensor
Inlet
Temperature
Sensor
Clip
Grey Leads
Orange Leads
Clip
Fig. 29. Flow switch.
Fig. 30.Flow switch filter.
Micro Switch
Seal
Outlet Union
Inlet Union
Cold Water
Inlet
Flow Switch
Flow Switch
Filter
O-Ring
Seal
Inlet Union
Loading
Plate and
Screws
Venturi