Flame Failure
(Pressing the manual
OK button on the
VTech Control Panel to
restart the ignition
sequence)
• The water heater has failed
to ignite the burner after 3
consecutive attempts
• Verify that all air has been purged from gas line.
• Inspect hot surface igniter and related wiring for damage and connection errors.
• Verify igniter is glowing and draws at least 3.0A.
• 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 4.
• Verify that the vent/ air inlet piping are correctly installed with no obstructions.
• Check wiring from VTech Controller, Gas Valve Transformer. If a signal cannot be
detected, the VTech Controller needs to be replaced
• If 24 VAC is present, check the valve. Connect a manometer to the outlet pressure
tap. Negative pressure should be present during pre-purge. When the valve is
energized the pressure should change. If not the gas valve has failed or is passing
insufficient gas. Consider adjusting combustion settings.
• Inspect the burner, and clean if necessary.
• Replace the VTech Controller
Flame Detection is
out of Sync
• Verify supply voltage for proper polarity.
• Check external wiring for voltage feedback
• Check internal wiring for proper connections
• Check the flame sensor and verify that it is clean
• Replace VTech Controller
• Tank Bottom sensor open
• Tank Top sensor open
• Flue sensor open
• Verify that the sensors are connected
• Verify that they are wired correctly.
• Measure the resistance of the sensors, 10kΩ sensors.
• Replace the sensor if necessary
• Refer to Part 3 Gas Connection in this manual.
• Natural Gas Pressure should read between 3” w.c. and 14” w.c.
• L.P. Gas Pressure should be at 11” w.c.
• Refer to Gas Valve Adjustment Procedure in section 10.2 of this manual for the
proper combustion setting.
• Air Inlet and/or vent
configuration
• Refer to Part 2 Air Inlet and Venting
• Refer to Burner Maintenance in section 9.7 of this manual for the burner removal and
inspection procedure. Clean or replace the burner, if required.
• Air in the piping system
• Purge all air from the piping system
• Check that display is connected to the PIM using a CAT5 cable on the back of the
display
• Reset VTech Controller
• If fault persists, replace VTech Controller
• Reset VTech Controller
• If fault persists, contact factory
9.8.1 – Flow Diagrams
Fault = “IGNITION FAIL”
This error occurs when a flame signal is not detected by the flame sensor. A minimum signal of 0.8Vdc must be detected by the
flame sensor to prove the flame.
Fault = “FLAME FAIL”
Move flame sensor wire away from harness
bundle
Separated from harness bundle
Check hot surface igniter for
minimum 3.0A reading
Check flame sensor for
carbon deposit