Replacing The Manifold/Burner Assembly; Testing The Igniter System - A.O. Smith GCV300 Service Handbook

3. Reassemble following
procedure under "Replacing the
Manifold/Burner Assembly."
Replacing the Manifold/
Burner Assembly
Explosion Risk
WARNING!
• Tighten both manifold door screws
securely.
• Remove any fiberglass between
gasket and combustion chamber.
• Replace viewport if glass is missing
or damaged.
• Replace manifold component block
if it is missing or has been removed.
• Replace door gasket if it is
damaged.
• Failure to follow these instructions
can result in death, explosion, or
fire.
1. Check the door gasket for damage
or imbedded debris prior to
installation. See Figure 22.
2. Inspect the viewport
damage and replace as required
(Figure 16, page 17).
3. Insert the new
burner assembly into the burner
compartment, making sure that
the tab of the manifold tube
engages the slot of the bracket
inside the combustion chamber.
See Figure 23.
CLOSE-UP INSIDE VIEW OF
THE COMBUSTION CHAMBER.
TIP
MANIFOLD TUBE
Figure 23.
the 4. Inspect the door gasket and make
sure there is no fiberglass insulation
between
combustion chamber. (Figure 22.)
5. Tighten the two screws that secure
the manifold/burner assembly to
the combustion chamber. (Use a
1/4" nut driver.) There should be no
space between the gasket part of
the manifold door and combustion
chamber
IMPORTANT: Do not operate the
water heater if the door gasket
does not create a seal between the
manifold door and the combustion
chamber.
6. Reconnect the manifold tube (3/4"
wrench) and pilot tube (7/16" wrench)
to the gas control valve/thermostat.
See Figure 15 on page 17.
cross-thread or apply any thread
sealant to the fittings.
IMPORTANT: If you were supplied
with a new ferrule nut in a parts kit,
follow these steps to connect the
pilot tube:
A.) Install the ferrule nut into the gas
valve at the pilot tube location,
hand tight only.
for
B.) Insert the pilot tube into the
ferrule nut until the tube
bottoms out, then tighten the
nut with a 7/16" wrench until
manifold/
the crimp connection seals to
the pilot tube.
C.) Continue to tighten until the nut
is tight in the gas valve.
7. Connect the white and red wires to
the gas control valve/thermostat
as shown in Figure 15, page 17.
Also, ensure that the red thermal
switch wires are connected to the
thermal switch (TCO switch) on the
manifold door. See Figure 21 on
page 18.
SLO T
8. Reconnect the igniter wire. (Figure
BRACKET
15, page 17).
the gasket and the
Do not
Residential Standard Gas Water Heater Service Handbook • 19
9. Turn on the gas supply to the water
heater at the manual gas shut-off
valve. (Figure 1, page 6).
10. Follow the lighting instructions
on the front of the water heater.
With the main burner lit, check
for leaks at the manifold and
pilot connections by brushing on
an approved noncorrosive leak
detection solution. If such a solution
is not available, use a mixture of
hand dish washing soap and water
(one part soap to 15 parts water)
or childrens' soap bubble solution.
Bubbles forming indicate a leak.
Correct any leak found.
11. Verify proper operation,
replace the outer door.
Tes ng the
System
The piezoelectric igniter system consists
of an igniter button, an electrode, and
wire. The pilot is ignited by an electric
spark generated when the igniter
button is pressed. See Figure 24.
THERMOPILE
PILOT
VAC
ELECTRODE
WIRE TO ELECTRODE
IGNITER BUTTON
Figure 24.
To test the igniter system, follow these
steps:
1. Turn off the gas to the water heater
at the manual gas shut-off valve.
(See Figure 1, page 6.)
2. Watch the electrode tip while
activating the igniter. (If the room
is dim enough, try looking through
the view port [Figure 16].)
A. A visible spark should jump from
the electrode. To avoid shock, do
not touch the burner or any metal
then
Igniter
PILOT/
THERMOPILE
BRACKET