Changing Components - Potterton Promax Ultra Combi 24 Installation And Service Manual

Spark Ignition
Electrode
Electrode
Leads
Flame Sensing
Electrode
Fig. 49
Control Box removed
for clarity
Cover
Gasket
Air/Gas
Collector
Gas Feed Pipe
36
© Baxi Heating UK Ltd 2016
Air/Gas
Venturi
Fan
Fig. 50
Gasket
Fig. 51
Fan

13.0 Changing Components

IMPORTANT: When changing components ensure that
both the gas and electrical supplies to the boiler are
isolated before any work is started. When the component
has been changed recommission the boiler as described in
Section 10.0. Always examine any seals or gaskets, replacing
where necessary. The Case Front Panel MUST seal
effectively against the air box side panels.
See Section 12.1 "Annual Servicing" for removal of case panel,
door etc.
13.1 Spark Ignition and Flame Sensing Electrodes
1. Disconnect the electrode leads, noting their positions.
2. Remove the retaining screws securing each of the electrodes
to the combustion box cover and remove the electrodes.
3. Check the condition of the sealing gaskets and replace if
necessary. Reassemble in reverse order.
4. After changing the Flame Sensing Electrode check the
combustion - see Section 14.1.
5. When satisfactory combustion readings are not obtained
ensure the electrode position is correct and perform the
combustion check again.
13.2 Fan (Fig. 50)
1. Remove the clip securing the gas feed pipe to the air/gas
venturi. Disconnect the pipe.
2. Undo the screws securing the air/gas collector to the cover
(33/40) or extension piece (24/28) and disconnect the fan
electrical plugs.
3. Remove the collector and fan assembly, being careful to
retain the gasket.
4. Undo the screws securing the fan to the collector. Retain
the gasket.
5. Undo the screws securing the venturi to the fan (noting its
position) and transfer to the new fan, replacing the seal if
necessary.
6. Examine the gasket(s) and replace if necessary.
7. Reassemble in reverse order and perform the Calibration
Function - see Section 14.2.
13.3 Air/Gas Venturi (Figs. 50 & 51)
1. Remove the clip securing the gas feed pipe to the venturi.
2. Undo the screws securing the collector to the cover (33/40)
or extension piece (24/28) and disconnect the fan electrical
plugs.
3. Remove the collector and fan assembly, being careful to
retain the gasket.
4. Undo the screws securing the venturi to the fan (noting its
Venturi position) and fit the new venturi, replacing the seal if necessary.
5. Examine the gasket and replace if necessary.
6. After changing the venturi check the combustion - see
Section 14.1.
(Fig. 49)