Heat Exchanger - Potterton Powermax HE 85 Litre Installation And Servicing Instructions

4.12

Heat Exchanger

Note: Replacing the heat exchanger
involves disconnecting the appliance from
the flue and air pipes. It is essential that the
flue system is fully reinstated and tested so
we recommend that
replacement flue pipe and fittings be
obtained before starting this work. The slip
fitting Part No.5106807
reinstating extended twin pipe flue systems.
Re-assemble all parts in reverse order.
1. Perform 4.1 General Access.
2. Check that the boiler primary system is
isolated from the mains water supply.
Release pressure from the primary
system and drain down.
3. Remove expansion vessel, pump, gas
valve, fan/venturi, diverter valve and heat
exchanger door (complete with burner) all
as detailed in previous sections. Remove
flow and return pipework from the push-fit
connections on RH manifold of heat
exchanger. Retain securing clips for re-
use.
4. Disengage air inlet duct from elbow on top
RH side of boiler and set aside. Unscrew
3 c/sunk screws and remove air inlet
elbow.
5. Disconnect wiring from temperature
sensors and overheat thermostat.
Carefully remove HT lead from spark
generator.
6. Disconnect flue pipe. Remove "hidden"
M6 nut - see Fig. 24, at RH rear of heat
exchanger and remove two M6 flanged
set screws securing the LH suspension
bracket. Support weight of heat
exchanger before removing the clip and
saddle beneath.
7. Lift heat exchanger vertically about 19mm
(3/4") to disengage condensate spigot
from its socket in the base panel; then tilt
forward from the bottom to remove.
Publication No. 5106226
the appropriate
will be helpful in
Heat Exchanger
PO
WE -
R
+
H.W . CH
MA INS BU RN TEM P
ON
ER
LO CK HW
OU
T
RES SEL
ET
C.H .
ADV +
ANC
E SEL
PR OG
-
PRO
G
To remove
Heat Exchanger
swing bottom forward
bottom of case Saddle
Condensate Pipe
(not supplied
with Heat Exchanger)
Disconnect
H. Exchanger
from LH
Support Brackets
Burner
Assembly
removed
Heat
Exchanger
Remove bottom
Clip from the Saddle
'O' Rings/Seals Kit
Gas (Part No. 5106295)
'O' Rings/Seals Kit
Water (Part No. 5106296)
Flue
Diecasting
Side View
of
Heat
Condensate
Exchanger
Transfer
Pipe
Condensate Trap
Grommet
Flue Seal
Flue
Diecasting
Disconnect
from RH
Support
Bracket
(which is
part of case)
Flow &
Return
Securing
Disconnect Flow
& Return Pipes
Saddle
Replacement of Parts
HE
Pipe
Clips
Fig. 24
35