Potterton Envoy Flowsure, Installation & Service Instructions Manual

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Servicing & Replacement of Parts
Publication No. 559779
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Servicing & Replacement of Parts – Page 24
Removing Combustion Chamber and Flue Hood - Continued.
9) Fold back flue sealing gaiter between the flue hood and flue elbow. FIG.17.
10) Carefully remove flue hood by moving the right hand side of the flue hood forward and gently guide the hood around the
flow tapping on the heat exchanger.
11) Pull combustion chamber forward until it is clear of the boiler casing.
Examination of Flue Ways and Cleaning
1) Place a sheet of clean paper over the inlet of the
condense syphon and the gas assembly. It is particularly
important that debris is prevented from entering the
short upward facing tube from the gas control valve.
2) Cleaning of the heat exchanger must be carried out
using a Potterton scraper Part No. 907736.
3) Working from below and above the heat exchanger
remove all deposits from between the fins.
4) Examine top and bottom sealing face of the heat
exchanger for deep scratches and remove any debris
with a soft brush to provide a smooth flat sealing face.
5) Examine Syphon for evidence of leakage or build up of
debris.
Note : Place a catch tray beneath the syphon cleaning eye
plug and remove plug this should remove any debris which
has collected in the pipe section. If necessary the syphon
should be removed and flushed with tap water. See
replacement of parts for further information.
Re-assembly of Boiler
6) Before reassembling combustion chamber and flue hood
to the boiler examine for the following:-
- The 'O' ring seals for damage
- The insulation in the combustion chamber. Note if there
is any visible deterioration of this material it MUST be
replaced
- Damage to the hot surface igniter
- Damage to the surface of the burner
- Damage to sight glass
- Build up of debris in the condensate sump (This may be
removed with a soft brush)
If any of the above components require changing see section
'Replacement of Parts' for further information.