Keston 50 - GC Installation And Servicing Instructions page 51

WD50/2/1997
7.8 HEAT EXCHANGER (Fig. 5.7.2 item 43)
i) Isolate the appliance (Section 7.1)
ii) Gain access (Section 7.2)
iii) Shut of the water supply to the appliance.
iv) Remove the burner head (Section 7.7)
v) Drain the system to below the level of the appliance using the drain off tap at the
base of the heat exchanger.
vi) Remove the boiler thermostat (Section 7.4.2)
vii) Remove the push on connectors to the water pressure switch, flow overheat
thermostat, flow high limit thermostat and flue protection thermostat taking note of
the correct positions.
viii) Remove the condensate trap (Section 7.10)
ix) Remove the pressure gauge phial located next to the drain off tap.
x) Disconnect the flow and return compression couplings to the flow and return
pipes exiting the top of the boiler.
xi) Remove the push on flue connection to the flue pipe exiting the top of the boiler.
xii) Remove the complete air filter assembly and flexible air pipe.
xiii) Remove the nut fixing the strap retaining the base of the heat exchanger and pull
out the strap by unhooking it from its fixing behind the heat exchanger.
xiv) Remove the allen screw securing the top of the heat exchanger to its mounting
bracket.
xv) Remove the five screws fixing the top of the cabinet.
xvi) Remove the heat exchanger, with pipework attached, & the top of the cabinet.
xvii) Separate the top of the cabinet from the combined assembly.
xviii) Remove the flow and flue pipework from the heat exchanger (Replacement heat
exchangers are supplied with return pipework attached).
xix) Reassemble (Section 7.3)
xx) Recommission (Section 4 - Commissioning)
7.9 AIR FILTER (Fig. 5.7.4 item 22)
i) Isolate the appliance (Section 7.1)
ii) Gain access (Section 7.2)
iii) Drop the lower section of the air filter housing by pulling forward the securing flap.
iv) Open the lower section as far as possible and pull out the combined paper filter
element with rubber seal.
v) Reassemble (Section 7.3)
NB:
7.10 CONDENSATE TRAP (Fig. 5.7.2 item 59)
i) Isolate the appliance (Section 7.1)
ii) Gain access (Section 7.2)
iii) Disconnect the condensate line from the base of the heat exchanger.
iv) Disconnect the condensate line from the base of the flue assembly.
v) Disconnect the condense lines from the projection of the condensate trap from
the base of the cabinet.
vi) Withdraw the condensate trap.
vii) Mop up any spilled condensate.
viii) Reassemble (Section 7.3)
NB:
Installation & Servicing Instructions
Chapter 7 : Replacement Of Parts
When fitting the new air filter take care to ensure that the new filter is
placed to cover completely the air intake entry into the boiler cabinet.
When re-fitting condensate trap pour water into the condensate hose
from the base of the heat exchanger until nearly full. Then reconnect the
condensate hose to the base of the heat exchanger.
Page : 48
The Keston 50, 60 & 80 Condensing Boilers