A.O. Smith BTX-100/GDHE-50 – Burner & Blower Removal

The burner should be removed and inspected whenever service is being performed for rough operation or ignition failure. Radial fire burners like the one used on this water heater can trap debris, see Service Notes – Venting on page 7.
The following images illustrate the burner removal procedure. Long T handle hex wrenches (8-10”) will save considerable time when removing/installing the burner & blower.

BLOWER/BURNER REMOVAL PROCEDURE
1 Ensure power to the water heater is turned off.
2 The blower assembly must be removed first.
3 Disconnect the two wiring plugs from the blower assembly sockets (see Service Notes – Blower page 10).
4 Disconnect the Blower Prover air pressure switch sensing tube.
5 Remove 4 blower flange mounting screws – 1/8” hex. Using long T handle hex wrench will save considerable time.Do not over tighten when reinstalling – torque should not exceed 40 inch lbs.
6 Remove the blower assembly from the blower adapter.
7 Remove the blower flange gasket. Gasket may be reused if not damaged or showing signs of excessive wear.
8 Remove the flame sensor – 1 Phillips head screw.

9 Remove 4 blower adapter 1/4” hex machine screws. Do not over tighten when reinstalling – torque should not exceed 40 inch lbs.
10 Remove the blower adapter.
11 Be extremely careful when handling the Sight Glass inside the Burner View Port (page 11) this can easily be dropped and lost – and the water heater must have the sight glass in place to operate safely.
12 Remove the hot surface igniter – 2 Phillips head screws.
13 Remove the blower adapter gasket. Gasket may be reused if not damaged or showing signs of excessive wear.
14 Lift the burner up and out.

Service Notes – Blower Flange & Blower Adapter Gaskets.

Whenever the blower or burner is removed for service DO NOT overtighten the machine screws that hold the blower flange to the blower adapter (page 12) or the blower adapter to the water heater tank (above). Torque on these screws should not exceed 40 inch lbs. If these mounting screws are overtightened the gaskets will be squeezed and deformed from their natural shape. This can partially block the flow of the fuel air mixture and cause rough starting, rough operation and ignition failure. If these gaskets are deformed from overtightening the mounting screws it can also lead to gasket leakage. Hot flue gases leaking from these points can burn up wiring, igniters, and other components.