39
Servicing should only be performed by a Quali
fi
ed Service Technician
COMBUSTION ANALYSIS PROCEDURE
Note:
The combustion analysis procedure must only be performed by a qualified service technician.
1. Turn the main power off to the water heater by placing the “On/Off” switch in the OFF position.
2. Remove the
fl
ue temperature sensor from the
fl
ue pipe connection.
Note
: Combustion measurements
will be made at this point.
3. Turn the main power on to the water heater by placing the “On/Off” switch in the ON position.
4. In Service Mode the water heater will
fi
re at ignition speed and will then modulate up to full
fi
re.
5. Insert the probe from a combustion analyzer into the hole left by the removal of the
fl
ue temperature
sensor.
6. Once the water heater has modulated up to full
fi
re, measure the combustion. The values should be in the
range listed in Table 12 below. The CO levels should be less than 150 ppm for a properly installed unit.
If the combustion is not within the speci
fi
ed range, refer to Table 13 below for possible causes and corrective
actions.
Table 12. Flue Products
NATURAL GAS
PROPANE (LP)
CO
2
O
2
CO
2
O
2
8.0% - 10%
3.0% - 6.5%
9.0% - 11%
4.1% - 6.9%
7. Once the combustion analysis is complete, test the safety shutoff device by turning the manual shutoff
valve to the OFF position and ensuring that the water heater shuts down and registers an alarm. Open
the manual shutoff valve, reset the control.
8. Turn the main power off to the water heater and replace the
fl
ue temperature sensor into the
fl
ue pipe
connection.
9. Place the water heater back into normal operation.
Replace the
fl
ue gas temperature sensor to prevent
fl
ue gas spillage into the room. Failure to comply could
result in severe personal injury, death, or substantial property damage.
Table 13. Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE
CORRECTIVE ACTION
Vent/Air Intake Length
or Obstruction
• Refer to Venting Installation section of the XP
Water Heater Instruction Manual for the proper
venting and air intake methods for the XP Water
Heater.
• Check for obstructions at the vent/air intake
terminals.
Gas Supply Pressure
• Refer to Gas Connections section of the XP
Water Heater Instruction Manual for the proper
gas supply for the XP Water Heater
Dirty/Damaged Burner
• Refer to Page 24 of this Service Handbook for
burner removal and cleaning procedures.
• Replace burner if necessary.
Gas Valve Adjustment
• Refer to Pages 40 and 41 of this Service
Handbook for the Gas Valve Adjustment
Procedure.
