Bock Water heaters OT300-A Installation And Operation Instruction Manual page 45

SECTION VII: TROUBLESHOOTING (cont.)
Table 14 should be referenced when troubleshooting the powered anode system. If the status
LED is off or flashing red, a problem has occurred and service is required. When the LED is a
constant green, the system is operating properly. NOTICE: The tank must be filled with
water prior to connecting the water heater to the power supply. The powered anode
system will only work properly if the tank is filled with water.
Table 14: Powered Anode Troubleshooting
LED status
The water heater is not connected to the power
OFF
supply.
Error occurred during start-up.
The tank is not filled with water.
Poor electrical connection between anode power
Flashing
supply and anode rod.
Red
Polarity is reversed due to incorrect wiring.
Defective seal in adode bushing; anode rod is no
longer insulated from tank.
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 operation.
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 disconnect 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 resistance 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
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 burner 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 next
subsection for instructions). Arrow down until the third screen that displays 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 stronger 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.
Problem Solution
Ensure that the water heater is plugged in.
Reset power to the anode power supply by resetting
the power supply to the water heater.
Disconnect water heater from power supply and fill
tank with water.
Check the insulation on all connecting harnesses
for bare spots. Check the connections at the power
supply and anode terminals.
Refer to the wiring diagram and correct polarity.
With an ohmmeter, check for electrical continuity
between the powered anode terminal and the
bushing. If there is continuity, replace the anode rod.
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