Pentair ETi 400 Guide D'installation page 8

8
Replacing Combustion Blower
Fire and explosion hazard. The Air Orifice is sized specifically for the air/gas
mixture required by the burner. Do not modify the Air Orifice or replace it with
an orifice of a different size.
Fire and explosion hazard. The Combustion Blower handles a combustible
air/gas mixture. When servicing this part, check all seals for tightness to
ensure that the Blower is not leaking.
1. Turn off the electrical supply to the
heater; turn off the pump; shut off the
manual gas supply valve to the heater.
2. Remove the side panels from the heater
to access the Gas Control Valve and
Combustion Blower. Using a flat-blade
screwdriver, insert press and turn the
screwdriver to unlock the panel, see
Figure 1.
3. Remove the water manifold service panel.
Using a flat-blade screwdriver, insert
press and turn the screwdriver to unlock the panel.
4. Turn the gas valve TOGGLE SWITCH to the OFF position.
5. Disconnect the wires to the blower at the connector.
6. Remove and discard the plastic tubing
between the blower, the air flow switch,
and the gas valve.
7. Using channel locks, loosen the gas
train at the two unions located near the
blowers and the union located near the
gas valve, see Figure 2.
8. Unscrew all the unions completely to
remove the gas train. Now the gas train
can be removed providing clearance to
remove the blower. Take care not to lose
both gas orifices, see Figure 2.
9. Disconnect the wires connected to the
air flow switch attached to the blower
being replaced.
10. Remove the four 5/16-18 hex nut from the blower adapter and slide
the blower outward through the studs of the blower adapter, see Figure 3 on
page 9.
Panel latch lock
Figure 1.
Figure 2.