Replacing The Fan On The Ex 700 And Ex 850 Models - IBC EX Series Installation & Operating Manual

Inlet gas pressure test port
Low pressure switch
Low fire adjustment (zero-offset)
High fire adjustment (on the side)
Manifold gas pressure test port
Shutoff valve
Figure 70 Gas valve and fan components - EX 700, 850

7.3.1 Replacing the fan on the EX 700 and EX 850 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 both the front and back electrical connectors from the fan, and position them out of the
way of the fan.
5. To separate the mixing device from the fan, remove the 6 x 6mm bolts. Note how the mixing
device is positioned on the fan before separating it from the fan.
Note: When you disconnect the mixer from the fan, it is still attached to the filter box and gas
valve. This puts pressure on the fan, filter box and gas valve assembly, which have limited
support. When you swap out the fan, place some sort of support underneath the mixer.
6. Remove the four (4) bolts at the base of the fan, connecting the fan to the heat exchanger lid.
7. Carefully lift off the fan, by pulling straight up and ensuring that no wires are caught, and that
the gas line remains in place. Place the removed components in a clean, dry area.
8. Attach the new fan.
9. Ensure that the O-ring is in place on the fan before reattaching the mixer.
10. Re-install the components in reverse order. Upon reassembly, ensure that all gaskets are
included and correctly positioned.
7.3.1 Replacing the fan on the EX 700 and EX 850 models
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