9REPAIR
T
HERMO
90 / 90 S
9-6
9.2.5 Replacement of Combustion Air Fan
9.2.5.1 Removal
1. Remove heater (see 8.7.1.1).
2. Disconnect electrical connections (see 9.2.1.1).
3. Remove screws (2, Fig. 9-4).
4. Pull combustion air fan (1) from burner head (4) and
remove together with profiled packing ring (3).
NOTE:
On heater Thermo 90 S with flanged control unit remove
control unit as required.
5. Perform procedures on components after
disassembly (see 9.1.1).
9.2.5.2 Installation
NOTE:
Locate packing ring (3, Fig. 9-4) properly; do not
squeeze.
1. Bring combustion air fan (1) with new profiled
packing ring (3) in assembly position and secure
with screws (2).
2. Torque tighten screws (2) with 3 Nm ± 10%.
NOTE:
On heater Thermo 90 S with flanged control unit install
control unit as required.
3. Make electrical connections (see 9.2.1.2).
4. Install heater (see 8.7.1.2).
Fig. 9-4 Replacement of Combustion Air Fan
