A.O. Smith BTX 100 Service Handbook page 17

6. disconnect the 24 Volt power wires to the 24 Volt Gas Valve at the two spade connectors in the wiring
harness to the valve, see Figure 14 below.
7. disconnect the Blower Prover switch sensing tube from the Combustion Blower outlet sensing port, see
Figure 14 below.
8. Turn off the supply gas to the water heater at the main gas shutoff valve serving the water heater.
9. disconnect the supply gas line to the water heater at the water heater's 24 Volt Gas Valve.
10. If the water heater has been installed in a direct Vent configuration, disconnect the intake air pipe at the
intake air connection on the water heater, see Figure 14 below.
11. Loosen the hose clamp closest to the Venturi on the Intake Air Elbow and remove the Intake Air Elbow
and Intake Air Connection fitting as assembled unit, see Figure 14 below.
12. using a small socket wrench with a 1/8 inch hex attachment or a long (8-10") T handle 1/8 inch hex (allen
key) wrench remove the four hex head machine screws that hold the Combustion Blower to the Burner
Adapter, see Figure 15 on page 16.
13. Lift the Combustion Blower up and off of the Burner Adapter, see Figure 15 on page 16.
14. Remove the orange silicone gasket.
15. Ensure the Blower discharge orifice is present and seated properly on top of the Burner Adapter, see
Figure 10 on page 13.
16. See the Service notes below for additional information.
Combustion blower installation
17. To re-install the Combustion Blower follow the steps for removal in reverse order.
18. Install a new orange silicone gasket between the Combustion Blower and the Burner Adapter.
19. do not overtighten the Combustion Blower hex head screws during installation, torque should be
approximately 3 foot lbs.
20. Restore power to the water heater and run it through at least one complete heating cycle before leaving
to ensure it is operating properly.
VENTURI
HOSE
CLAMP
INTAKE AIR
ELBOW
COMBUSTION BLOWER ASSEMBLY TOP VIEW
24 VOLT GAS VALVE
SUPPLY GAS CONNECTION
INTAKE AIR CONNECTION FITTING
Servicing should only be performed by a Qualified Service Agent
Figure 14
COMBUSTION BLOWER
OUTLET SENSING PORT
24 VOLT GAS VALVE
WIRING HARNESS
SPADE CONNECTORS
COMBUSTION
BLOWER
15