IBC SL 35-199 Operating Instructions Manual

Also see for SL 35-199: Quick start guide

IBC SL 35-199 Operating Instructions Manual Manual pdf 51 page image

5-3TROUBLESHOOTINGSL 35-199, SL 45-260 MODULATING GAS BOILERS5.2.2 Fan/BlowerOperating power is provided by means of a separate 120 VAC connector at thebottom of the fan (white/black/green). Control of the fan is provided via a fourlead connector at the top of the fan. This connector feeds a PWM control signal(black wire) from the controller and provides a tachometer signal (white wire)back from the fan. Unplugging the control connector will cause the fan to go tohigh speed and trigger a “Blocked Vent Error” within 6 seconds if the boiler isoperating.LEAD COLOR FUNCTION TROUBLESHOOTINGRed 35 VDC Positive powerterminalFan will only operate at max. speed ifdisconnected.Blue 35 VDC Negative powerterminalFan will only operate at max. speed ifdisconnected.Black Signal from controller Fan will only operate at max. speed ifdisconnected.White Fan tach. 2 pulses/rev (freq x 30=rpm)Table 10: Fan Operation5.2.3 Differential Air Pressure SensorDo not blow into the ports of the sensor, this is not a switch and “does notclick when closed”. Excessive pressure will damage the sensor thus requiringreplacement. The sensor values are located in the advanced diagnostics sectionof the controller. In general, the Fan Pressure and the Required Pressureshould be very close to each other while the boiler is in operation. If the requiredpressure is higher than the actual pressure there are several possible causes.• Exhaust and/or Air Intake piping installed longer that allowed• Improper grading of the Exhaust and/or Air Intake piping allowing condensateto be trapped in the piping• Re-Ingestion of flue gasses has caused the Venturi and/or Fan Impeller toerode, becoming ineffective.• Air Pressure Sensor tubing not correctly attached.5.2.4 Water Pressure SensorThe water pressure sensor ensures there is adequate pressure in the heatingsystem for safe operation. The pressure is displayed in PSI as the default. If thesystem pressure should drop below 8PSI the firing rate of the boiler is reduced.If the pressure drops to 4PSI or lower, the boiler will not fire.Check operation of the sensor by isolating the boiler from its system piping,closing the system fill valve then cracking the pressure relief valve; the pressuredisplayed should reflect declining pressure. If it remains “fixed”, drain boiler andreplace sensor, or dislodge any blocking debris from sensor inlet channel andreinsert.Control wire plugAir pressure sensor. Do not blowinto sensor ports.Water pressure sensor