SERVICE HANDBOOK

ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUALFAULT MESSAGES (CONT)DISPLAYED MESSAGECONDITION/INDICATES“Upper Probe Short”The control system has detected less than 390ohms from the Temperature Probe on top of thewater heater.CHECK/REPAIR• Check all wiring between the TemperatureProbe and the J7 Socket on the CCB (page 36).Repair/replace anything worn or damaged.• Unplug J7 plug from CCB, check resistancebetween the two black wires in the plug end withan ohm meter. If resistance is at or below 390ohms - replace the Temperature Probe.• Call the technical support phone number shownon the water heater labeling for further assistanceif the problem has not been correctedafter performing the procedures outlined here.“Flame Probe Short”The control system has detected that the flamesensor is grounded.• Disconnect the wire from the flame sensor (seepages 12 and 24). Check for continuity betweenflame sensor and ground with an ohm meter.There should be no continuity - infinite resistance.• If above test indicates there is continuitybetween the flame sensor and ground - removethe flame sensor (see pages 12 and 24). Ensurethe flame sensor is not bent and touching theburner.• Check all flame sensor wiring between theflame sensor and the J4 male spade connectoron the CCB (page 36). Ensure there are not anypinched wires or shorts - repair/replace anythingworn or damaged.• Replace the flame sensor.• Call the technical support phone number shownon the water heater labeling for further assistanceif the problem has not been correctedafter performing the procedures outlined here.Technical Literature Department 44 of 52 Ashland City, TN © 2008Servicing should only be performed by a Qualified Service Agent