34
CAUTION
Never use a pressure washer to clean the burner
The burner may best be cleaned by immersing the burner port
area in a solution of dishwashing detergent and hot water.
Allow the burner to remain in the solution for a short period of
time to loosen dust, dirt and oil or grease laden contaminants.
Rinse the burner thoroughly with clean water to remove any
residue from the detergent cleaner. The burner should be air
dried after removal from the cleaning solution and rinsing.
DO
NOT
use chlorine based solvents or cleaning agents.
9.5
– Check the Condensate Neutralizer –6 Months
Neutralizer medium is expected to last approximately three to six
months depending on the amount of condensate produced.
Condensate Produced, USgal/h = [KBtu/h Input / 100]
In higher temperature systems less condensate will be produced,
extending the life of the neutralizer media. Media viability can be
verified with pH test strips (i.e. litmus paper). Replace media as
needed to maintain neutral state of discharged condensate, as
required by code.
9.6
– Draining and Flushing – Annual
It is recommended that the water heater tank be drained and
flushed annually to reduce sediment buildup. The water heater
should be drained if being shut down during freezing
temperatures.
9.7
– Complete the Service
Update the appliance service records immediately upon
completing service.
Restore electrical power and gas supply to appliance.
Cycle unit and check for proper operation. At minimum the
following parameters should be checked to verify they fall
within acceptable limits. Deviation from the readings made
during commissioning can also indicate a problem that is
otherwise undetectable.
o
Verify all combustion settings, including incoming gas
pressure, differential air pressure, and
CO
2
settings (see
Section 8).
o
Visually inspect burner flame to verify combustion.
Confirm proper operation of all safety devices.
Check for gas leaks and proper vent operation.
Check control settings.
Install top cover once all checks and adjustment are
complete.
9.8
– Troubleshooting
SYMPTOM
FAILURE MODE
ANALYSIS
Incoming Power
• Two wires interchanged
• No effect on safety
• Live and Neutral wires are interchanged.
Transformer Tripped
• The 24Volts and 120 Volts
wired are interchanged
• Transformer immediately burns out, replace transformer
Relief Valve
• System pressure exceeds
relief valve setting
• Replace the standard relief valve with a higher rated valve up to the maximum
pressure of the heat exchanger.
• Improperly sized expansion tank.
Low Water Cut-Off
• LWCO contacts are open
• Verify for closed valves or obstructions in water heater piping
• Verify that all air has been purged from the system
• Verify that wiring is correct
Stack Temperature
Limit Trips
• Stack temperature has
exceeded the limit set on
the water heater.
• Error: FLUE MAX
• PVC: Reduce desired setpoint to less than 140
o
F.
• Measure the resistance of the flue sensor at room temperature, it should be
approximately 10kΩ.
• PVC: 149
o
F
• CPVC: 194
o
F
• PPE: 230
o
F
• Stainless Steel, AL29-4C: 250
o
F
Blocked Flue Switch
•
Error: FLUE OPEN
• Blocked flue switch wire(s) is/are loose
• Blocked flue switch is set too light if it trips at full fan speed, reduce sensitivity by
turning screw 1 turn clockwise.
Fan Not Turning
• Fan refuses to rotate
•
Error: BLOW SPD
• Check fan power wires
• Fan signal wires are interchanged
• Minimum fan speed must be greater than 10%
Flame Disappears
During a Run Cycle
(Pressing the manual
OK button on the
VTech Control Panel to
restart the ignition
sequence)
• The VTech water heater
was running and flame
signal suddenly
disappeared.
• Verify that all air has been purged from gas line
• Inspect hot surface igniter and related wiring for damage and connection errors.
• Inspect flame sensor and associated wiring. Replace if necessary
• Verify that water heater is properly grounded
• Verify incoming gas supply pressure and that it coincides with Table 9.
• Verify that the gas line connections to the water heater are adequate
• Verify that the vent/ air inlet piping (if equipped) are correctly installed and
obstructions are not present
• Verify that 24 VAC is being supplied to the gas valve during ignition. If a signal
cannot be detected, the transformer needs to be replaced
• Inspect the burner. Refer to Burner Maintenance in section 9.7
• Replace the VTech Controller if necessary