52
TROUBLESHOOTING
Flow Chart.
1.
When the control system is first powered, during boot up, the
blower will run momentarily and stop, and the control system
will display water heater model information during initialization.
After a few moments the control system LCD which is part of
the UIM (user interface module) will display the default screen
known as the Desktop screen.
2.
If the control system determines that the actual water
temperature inside the tank is below the programmed
Operating Set Point minus the Differential setting, a heating
cycle is activated.
3.
The control system then performs selected diagnostic system
checks. This includes confirming the blocked exhaust, blocked
intake and ECO (energy cut out) switch contacts are closed.
The Blower Prover Switch contacts are confirmed open.
4.
If all diagnostic checks are successfully passed, the control
system energizes the Combustion Blower for pre-purge.
5.
The control system must confirm the Blower Prover Switch
contacts close after the Combustion Blower is energized.
6.
If the Blower Prover Switch contacts are confirmed closed the
control system energizes the spark igniter.
7.
After a few seconds, the control system energizes the 24V
Gas Control Valve allowing gas to flow to the Main Burner.
8.
The control system monitors the flame sensor to confirm a
flame is present at the Main Burner. If a flame is not verified
during the ignition trial period the control system will try for
ignition up to two more times. If flame can not be verified after
three trials for ignition, the control system will lock out and
display the Ignition Failure Fault message.
9.
If a flame is verified, the control system will enter the
heating mode where it will continue heating the water until
the Operating Set Point is reached. At this point, the control
system will de-energize the 24 V Gas Control Valve and
enter the post-purge cycle (60 seconds).
10.
The control system de-energizes the spark igniter.
11.
The Combustion Blower will run for the duration of the post-
purge cycle to purge the water heater of all combustion gases.
When the post-purge cycle is complete, the blower is de-
energized and will coast to a stop.
12.
The control system now enters the standby mode while
continuing to monitor the internal storage tank water
temperature and the state of other system devices. If the tank
temperature drops below the Operating Set Point minus the
Differential setting, the control will automatically return to Step
2 and repeat the operating cycle.
INSTALLATION CHECKLIST
The list below represents some of the most critical installation
requirements that, when overlooked, often result in operational
problems, down time and needless parts replacement. This is not
a complete list. Before performing any troubleshooting procedures
use the list below to check for installation errors. Costs to correct
installation errors are not covered under the limited warranty.
Ensure all installation requirements and instructions in this manual
have been maintained and followed.
WATER HEATER LOCATION
1. Ensure proper clearances to combustibles are maintained and
there is sufficient room to service the water heater.
2. Ensure the area is free of corrosive elements and flammable
materials.
VENTING
3. Ensure the intake air and/or vent (exhaust) piping is the correct
size for the installed length.
4. Ensure the maximum equivalent feet of pipe has not been
exceeded for the intake air and/or vent pipe.
5. Ensure the maximum number of elbows has not been exceeded
in the intake air and/or vent pipe.
6. Ensure all exterior clearances for the intake air, vent and
concentric terminations are maintained. These clearances and
those cited by local and national codes must be maintained.
7. If venting direct vent, ensure the screen located in air intake at
the water heater was removed.
GAS SUPPLY AND PIPING
8. Ensure the supply gas line to each water heater meets the
minimum supply gas line size requirements.
CONDENSATE DRAIN
9. Ensure the condensate drain is properly connected to the
exhaust elbow on the water heater and draining freely to a
suitable floor drain.
ELECTRICAL CONNECTIONS
10. Ensure the water heater is properly grounded. Flame sensing
requires an adequate earth ground. If the water heater is not
properly grounded it will cause Ignition Failure.
SEQUENCE OF OPERATION
Read the Sequence of Operation below before attempting to
correct any operational problems. See the Sequence Of Operation
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