24
Servicing should only be performed by a Quali
fi
ed Service Technician
Inspect ignition and
fl
ame sense electrodes
1. Remove the ignition and
fl
ame sense electrodes from the water heater heat exchanger access cover.
2. Remove any deposits accumulated on the ignition/
fl
ame sense electrode. If the electrodes cannot be
cleaned satisfactorily, replace with new ones.
3. Replace
ignition/
fl
ame sense electrode, making sure gasket is in good condition and correctly positioned.
Check ignition ground wiring
1. Inspect water heater ground wire from the heat exchanger access cover to ground terminal strip.
2. Verify all wiring is in good condition and securely attached.
3. Check ground continuity of wiring using continuity meter.
4. Replace ground wires if ground continuity is not satisfactory.
Check all water heater wiring
1. Inspect all water heater wiring, making sure wires are in good condition and securely attached.
Check control settings
1. Use the UIM control display to access MENU and check all parameter settings.
2. Check settings of external limit controls (if any) and adjust if necessary.
Perform start-up and checks
Note:
The start-up must only be performed by a qualified service technician.
1. Start water heater and perform checks and tests speci
fi
ed in Start-up section of the XP Water Heater
Instruction Manual.
Check burner
fl
ame
1. Inspect
fl
ame through observation window.
2. If the
fl
ame is unsatisfactory at either high
fi
re or low
fi
re, turn off water heater and allow water heater to
cool down. Remove the burner (see Figure 6 below) and clean it thoroughly using a vacuum cleaner or
compressed air. Do not use compressed air to clean burner if performed inside a building.
3. When replacing the burner, ensure gasket is in good condition and positioned correctly (See Figure
below).
Figure 6. Burner Assembly
