Keston 50 - GC Installation And Servicing Instructions page 48

WD50/2/1997 Chapter 7 : Replacement Of Parts
7.4.3
7.4.4
7.4.5
7.4.6
Installation & Servicing Instructions
Neons (Fig. 5.7.1 items 116 & 117)
i) Isolate the appliance (Section 7.1)
ii) Gain access (Section 7.2)
iii) Remove the push on connectors from the neon taking note of the correct
positions.
iv) Press in the catches and push the neon forward through the control
panel.
v) Pull the centre core of the neon from its housing to expose the bayonet
fitting bulb.
vi) Reassemble (Section 7.3)
vii) Check for correct operation of the neons.
Flow Overheat (Fig. 5.7.2 item 75) , Flow High Limit (Fig. 5.7.2 item 78) & Flue
Protection Thermostats (Fig. 5.7.2 item 70)
i) Isolate the appliance (Section 7.1)
ii) Gain access (Section 7.2)
iii) Remove the push on connectors from the thermostat taking note of the
correct positions.
iv) Unscrew the two retaining screws and remove the thermostat.
v) Flue protection thermostat only
The thermostat seal is maintained via a small 'O' ring between thermostat
and flue pipe. If this is damaged on removal it must be replaced.
vi) Reassemble (Section 7.3)
NB: When fitting the new thermostat it is a requirement to smear a
thin film of heat sink compound between the thermostat and
plate. This, combined with fitting the new thermostat tightly to the
plate, ensures a good contact.
Water Pressure Switch (Fig. 5.7.2 item 79)
i) Isolate the appliance (Section 7.1)
ii) Shut off the water supply to the appliance.
iii) Gain access (Section 7.2)
iv) Drain the system to below the level of the appliance using the drain off
tap at the base of the heat exchanger.
v) Remove the push on connectors from the water pressure switch taking
note of the correct positions.
vi) Unscrew the pressure switch.
vii) Reassemble (Section 7.3).
NB: Use a little jointing compound or PTFE tape on the thread.
viii) Refill the system (See Section 4 - Commissioning).
Ignition Control Box (Fig. 5.7.1 item 108)
i) Isolate the appliance (Section 7.1)
ii) Gain access (Section 7.2)
iii) Remove the HT ignition lead.
iv) Pull off the multi-pin connector away from the box.
v) Unscrew the two screws securing the control box to the casing and
remove the box.
vi) Reassemble (Section 7.3)
Page : 45
The Keston 50, 60 & 80 Condensing Boilers