8.4.2
Boiler Flow and Return Thermistors
(Fig. 6.7.2 - 2/3 item 67)
i)
Isolate the appliance (Section 8.1)
ii)
Gain access (Section 8.2)
iii)
Remove the push on connectors from the thermistor taking note of the correct
positions.
iv)
Unclip the thermistor from the pipe.
v)
Reassemble (Section 8.3)
NB:
When fitting the new thermistor it is an advantage to smear a thin film
of heat sink compound between the thermistor and pipe. This,
combined with fitting the new thermistor tightly to the pipe, ensures a
good contact.
8.4.3
Cabinet Temperature Sensor
(Fig 6.7.1 item 153)
i)
Isolate the appliance (Section 8.1)
ii)
Gain access (Section 8.2)
iii)
Remove the cabinet temperature sensor from the connector block by
slackening the retaining screws.
iv)
Reassemble (Section 8.3)
8.4.4
Flue Thermistor
(Fig. 6.7.2 - 1/3 item 68)
i)
Isolate the appliance (Section 8.1)
ii)
Gain access (Section 8.2)
iii)
Remove the push on connectors from the thermistor taking note of the correct
positions.
iv)
Unscrew the retaining nut, and remove the thermistor.
v)
Reassemble (Section 8.3)
NB:
When fitting the new thermistor it is an advantage to smear a thin film
of heat sink compound between the thermistor and plate. This,
combined with fitting the new thermistor tightly to the plate, ensures a
good contact.
8.4.5
Pressure Sensor
(Fig. 6.7.2 - 2/3 item 112)
i)
Isolate the appliance (Section 8.1)
ii)
Shut off the water supply to the appliance.
iii)
Gain access (Section 8.2)
iv)
Drain the system to below the level of the appliance using the drain off tap
(fig. 6.7.4 - 2/2 item 180) at the base of the return pipe from the heat
exchanger.
v)
Remove the push on connectors from the pressure sensor taking note of the
correct positions.
vi)
Unscrew the pressure sensor.
vii)
Reassemble (Section 8.3).
NB:
Use a little jointing compound or PTFE tape on the thread.
viii)
Refill the system (See Section 5 - Commissioning).
8.4.6
Main Control Box
(Fig. 6.7.1 item 135)
i)
Isolate the appliance (Section 8.1)
ii)
Gain access (Section 8.2)
iii)
Pull off the multi-pin connectors and HT lead away from the board.
iv)
Remove the retaining screw (fig. 6.7.1 item 152) securing the control block to
the gas valve (fig. 6.7.3 item 126).
v)
Remove the control box.
vi)
Reassemble (Section 8.3)
8.4.7
Combustion Blower
(Fig. 6.7.3 item 119)
i)
Isolate the appliance (Section 8.1)
ii)
Gain access (Section 8.2)
iii)
Disconnect the two connector blocks from the combustion blower.
iv)
Unscrew the bolts securing the venturi (fig 6.7.3 item 125) to the inlet port of
the combustion blower.
v)
Remove the four nuts securing the combustion blower (fig. 6.7.3 item 121)
outlet flange to the burner and remove the combustion blower.
vi)
Reassemble (Section 8.3)
WD388/0/2004 Chapter 8 : Replacement Of Parts The Keston C36 Combi & C36P Combi Boilers
Boilers
Installation & Servicing Instructions
Page : 43
