Potterton Prorile Prima 30e Installation And Servicing Instructions page 22

SERVICING INSTRUCTIONS - Page 22
C Remove screws securing the combustion chamber front
panel and remove panel.
D Disconnect the two flexible tubes from the flue elbow.
E. Remove thumb screw securing the flue elbow and withdraw
elbow. Take care not to damage the gasket. On vertically
flued boilers remove two thumb screws and slide the vertical
flue adapter up into the flue duct.
F. Disconnect the fan supply and earth leads from the connector
adjacent to the fan. Remove the two wing nuts securing the
flue hood to the heat exchanger. Lift out fan/flue hood
assembly.
Lower and lift out vertical adapter.
G. Undo the union on the gas service cock outlet.
H. Unplug the electrical supply leads for the gas control valve
from control box. See FIG. 28.
I. Remove the screw securing the gas control valve to its
support bracket. See FIG. 28.
J. Disconnect the electrode lead from electrode.
K. Remove two screws securing the burner assembly to the
bottom of the boiler case and lift out the burner and gas
control assembly.
2. HEAT EXCHANGER
A. Working from above and below the heat exchanger use a
suitable tool and remove all deposits from between the fins.
Slide vertical flue adapter into flue duct.
3. FAN
A. Separate fan from fluehood by removing the two securing
screws.
Carefully clean any deposits from around the fan motor and
its supports. Examine the fan wheel and clean if necessary
using a soft brush.
Re-assemble fan to fluehood ensuring that the sealing gasket
is in place and in good condition. Ensure also that the fan is
located correctly in the rear retaining bracket.
Secure with two screws.
B. Refit the fan/fluehood assembly. Ensure that the rope seal is
in place and the rear of the fluehood is correctly located
beneath the retaining flange. See FIG. 17. Secure with two
wing nuts.
C. Slide flue elbow into the flue duct or lower flue adapter and
secure with thumb screws. Ensure that the gasket between
fan outlet and elbow or adapter is undamaged and in place.
D. Reconnect the flexible tubes to elbow or adapter.
ENSURE THEY ARE NOT LINKED
NOTE
Red tube connects front aluminium tube to the lower
connection on elbow or adapter each being identified with a
red ring.
E. Reconnect the fan supply and earth leads.
4. PILOT BURNER
The following operations are only necessary if the pilot flame is
distorted or the wrong size, ie too small.
A. Unscrew the pilot tube from the pilot assembly. Take care not
to damage the electrode.
B.
C.
D.
E.
F.
G.
H.
FIG. 29 PILOT BURNER SPARK GAP TOLERANCES
PILOT FILTER
5.
A.
6.
.
A.
Unscrew the two hexagonal head screws securing the pilot to
the main burner and remove pilot assembly and shield where
fitted, be careful that the pilot injector does not fall out during
this operation.
Lightly brush the pilot to remove any deposits. Remove the
pilot injector and clean its orifice or replace.
NOTE
Do not use a wire brush or pin to clean injector.
Gently clean any deposits from the electrode.
Refit the pilot injector to the pilot burner and assemble the
pilot to the pilot tube.
Secure the pilot assembly to the main burner using two
hexagonal screws.
Fully tighten the union nut connecting the pilot tube to the
pilot. Check for gas soundness at this joint by following the
procedure described in the commissioning section of these
instructions. Page 18.
Ensure that the spark gap is as illustrated in FIG. 29.
The pilot burner is protected from blockage by a pilot filter
situated within the gas control valve. The filter is large and
designed to last the life of the gas control valve under normal
operating conditions, it is therefore unlikely to need replacing.
However in the event of pilot filter blockage being suspected
the complete control valve should be replaced.
COMBUSTION CHAMBER INSULATION
Check the combustion chamber insulation for damage. If
damaged replace as described under replacement.
MAIN BURNER
Lightly brush any deposits from the top of each blade and
ensure there is no fluff in the entry of the burner venturi. If on
re-assembly the burner flame picture is incorrect or the
correct gas rate or burner pressure cannot be obtained,
remove the burner and gas control assembly and thoroughly
clean the burner. Clean or replace the injector. In the event of
the above procedures not rectifying the flame appearance,
disconnect the burner from the gas control valve at the
flanged connection and replace the burner and injector.