9Repair Thermo 90 S / Thermo 90 ST
906
9.2.5 Changing the combustion air fan
9.2.5.1 Removal
1. Remove the heater (see 8.7.1.1).
2. Disconnect the electrical connections (see 9.2.1.1).
3. Remove the screws (2, Fig. 904).
4. Pull the combustion air fan (1) off the burner head (4)
and remove together with the shaped sealing ring (3).
NOTE
Remove the control unit if necessary from the
Thermo 90 S/Thermo 90 ST heater with flange-
mounted control unit.
5. Complete the work on stripped-down components
(see 9.1.1).
9.2.5.2 Fitting
NOTE
Insert the shaped seal (3, Fig. 904) correctly and grease it
(e.g. with Vaseline). Take care not to squash it.
1. Fit the new shaped sealing ring (3) onto the
combustion air fan (1). Bring the fan into the assembly
position and secure it with screws (2).
2. Tighten the screws (2) to 3 Nm ±10%.
NOTE
Install the control unit if necessary on the Thermo
90 S/Thermo 90 ST heater with flange-mounted
control unit.
3. Connect the electrical connections (see 9.2.1.2).
4. Install the heater (see 8.7.1.2).
Fig. 904 Changing the combustion air fan
Thermo 90 S
Control unit
1
2
3
4
1
1 Combustion air
fan
2 Screw (2)
3 Shaped sealing
ring
4 Burner head
Control unit
NOTE
A Thermo 90 ST heater is shown.
