Replacing The Fan On The Ex 400 And Ex 500 Models - IBC EX Series Installation & Operating Manual

Low fire adjustment
Mixing device
Figure 51 Gas valve and fan components - EX 400, 500

7.2.1 Replacing the fan on the EX 400 and EX 500 models

1. Turn off the electric power and gas supply to the boiler.
2. Ensure the boiler cools down to the surrounding temperature. Do not drain the boiler
unless freezing conditions are expected during this procedure.
3. Remove the front cover, and then remove the boiler's top panel by removing the Torx
screws on the top panel of the boiler.
A ladder or step may be required to have a clear vertical view of the work area. Do not
attempt to reach from the front without a clear view, as damage to connectors, screws or
refractory may occur.
4. Unplug the electrical connectors on the front and back of the fan.
5. Position the harnesses out of the way of the heat exchanger lid.
6. Pull away the air intake tube (can slide into the filter box) from the fuel mixer (see
52 ).
Figure 52 Air intake tube
7. Use a 3mm Allen key to remove the three (3) screws connecting the mixing device to the
fan. (See Figure 53
reassembly.
). Ensure that the fan O-ring stays seated in the fan groove during
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Section: Service and maintenance
Figure