SERVICE HANDBOOK

ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUALSEQUENCE OF OPERATIONCall for heat initiatedAir Pressure Switch Test Is PerformedBlower Prover Switch is verified openBlocked Intake and Blocked Exhaust Switches are verified closedYESBlower Motor is energizedPre-purge StateBlower Prover Switch is verified closedYESIgniter is energized for warm up period(approx 17 seconds)NONOControl System DeclaresFault Condition - Locks OutOne of the followingFault Messages Displayed:“Blower Prover Failure”“Blocked Inlet”“Blocked Exhaust Vent”Control System DeclaresFault Condition - Locks Out“Blower Prover Open”Fault Message DisplayedControl System (CCB) Verifies IgniterCurrent at 2.0 AC Amps MinimumYESNOControl System DeclaresFault Condition - Locks Out“Low Igniter Current”Fault Message DisplayedGas Valve Is EnergizedGas Flows To BurnerControl System (CCB) Verifies FlameSensing Current at 1.0μA DC Micro Amps MinimumYESNOWater Is Heated ToOperating Set PointGas Valve IsDe-energizedGas Valve IsDe-energizedInter-Purge State30 Sec ApproxPost-Purge State30 Sec ApproxRetries Up To3 TimesControl System Goes IntoStandby State/ModeControl System DeclaresFault Condition - Locks Out“Ignition Failure”Fault Message DisplayedTechnical Literature Department 40 of 52 Ashland City, TN © 2008Servicing should only be performed by a Qualified Service Agent