49P/N HN-IOM-1 82-0331 Copyright 2009 Mestek, Inc.Finned copper tube gas boilers & water heaters – Control manualStatus screen fault displays — when fault is tripped, display will show fault message, beep and close the alarm contact (forTable 11remote alarm); the fault displays for a second, then is followed by the time the fault occurred. The fault and time toggle once persecond until the condition is corrected. NOTE: Momentary closure across J10B terminals ALARM SILENCE will silence the alarm.FAULT EVENT &INTERLOCKTERMINALSCAUSE/Discussion DISPLAY Action required toreset from faultAIR SWITCH (BLOWER) Occurs if the blower remains in prepurge longer than twominutes. The boiler is shut down until the fault is corrected.The display continues showing the SUPPLY, HEADER orother temperature, whichever had been selected for display.The temperature shown is the value detected at the sensorlisted.FAULT SUPPLYAIR SWITCH (BLOWER)168°FAutomatically resetscontrol after externallimit closesCOMBUST AIR DAMPER(J12B, terminals 7 & 8)Occurs if closure isn’t detected across J12B terminals 7 and8 within the allowable time after the damper is activated viathe J13 BOILER3/DAMPER contact.LINKED/COMMON damper operation (single, commondamper):The system is shut down until the fault is corrected, butattempts a restart every 10 minutes.INDEPENDENT damper operation (a damper for eachboiler):The individual boiler is shut down until the fault iscorrected and the ON/OFF switch is cycled.The display continues showing the SUPPLY, HEADER orother temperature, whichever had been selected for display.The temperature shown is the value detected at the sensorlisted.FAULT SUPPLYCOMBUSTION AIR DAMPER168°FMASTER boiler —Automatically resetscontrol after externallimit closesMEMBER boiler orstand-alone boiler —Requires cycling ofthe boiler ON/OFFswitchFLOW SWITCH ERROR(J11B, WTR FLW)Occurs on failure to close of a flow switch connected toJ11B WTR FLW terminals. The boiler will restart every 10minutes, attempting to prove flow.The display continues showing the SUPPLY, HEADER orother temperature, whichever had been selected for display.The temperature shown is the value detected at the sensorlisted.FAULT SUPPLYWATER FLOW SWITCH168°FAutomatically correctsif flow is provenTroubleshooting (continued)9Fault indicationsThe HeatNet control monitors both boiler and external interlocks, and willshut down the boiler and display a fault code when a problem occurs. SeeTable 11 for details.Some faults will cause the control to shut down the boiler orsystem and display the message. CALL FACTORY. Shouldthis message appear, immediately contact RBI for assistance.DO NOT attempt to correct the condition withoutdiscussing the issue with the factory. Failure to comply couldresult in severe personal injury, death or substantial propertydamage.