Rheem GHE 119-500 Use & Care Manual page 33

Servicing The Flame Rod and Ignitor
If an A01 lockout error code is present there
has been a problem with lighting the burner.
Two possible causes for this error are a dirty
or faulty flame rod or a faulty ignitor. Each
component can be checked for proper opera-
tion.
The hot surface ignitor can be checked with a
visual inspection through the burner assembly
sight glass. Before the gas valve opens in the
ignition sequence, the ignitor will warm-up
for 20 seconds. During this time, an orange
glow will be visible through the sight glass. If
accessing the sight glass is not feasible, two
simple checks can be made with a multimeter.
First, ignitor resistance may be measured at
the end of the ignitor wiring terminal. Turn off
power to the water heater and dissconnect the
ignitor wire harness from the wire harness with
the two orange wires. Insert the multimeter
probes into the ignitor wire harness terminal.
At normal room temperature, the ignitor re-
sistance will be approximately 38 ohms. After
a heating cycle, the resistance will be in the
range of 38 - 80 ohms (depending on when the
measurement is taken after the cycle). Besides
resistance, the continuity of the ignitor circuit
Troubleshooting
33
can be checked. With the multimeter probes
still in the terminal, switch the meter to check
for continuity. If continuity is not indicated, the
ignitor must be replaced.
If the ignitor is working properly and the burn-
er lights but goes out right away, check the
flame rod. The rod may be dirty or it could be
damaged and a replacement will be required.
Start by turning off power to the water heater
and remove the flame rod. Inspect the ceramic
insulator for cracks (replace if cracked). Clean
the rod with fine steel wool and reinstall. Turn
on power to the water heater and enter the
Installer Menu on the control display (see table
10). Arrow down until the third screen that dis-
plays the flame signal. During the next ignition
attempt, a flame signal (in microamps, "uA")
will be displayed. Under normal operation, the
flame signal will be between 2 - 5 uA during a
successful ignition period. As the fan speed
increases the flame signal will become stron-
ger and eventually be in the 5 - 7 uA range. A
minimum flame signal of 1.25 uA is required
to avoid a flame failure. If the flame signal is 0
uA when a flame is present during the ignition
period, the flame rod needs to be replaced