ICP 9MAC/E series Troubleshooting Manual

Contents

ICP 9MAC/E series Troubleshooting Manual Manual pdf 8 page image

- 8 -8 GAS HEATING LOCKOUT – Control will NOT auto reset. Check for:- Stuck closed gas valve relay on control.- Miswire or short to gas valve BLUE wire.9 MEDIUM PRESSURE SWITCH, HIGH PRESSURE SWITCH, OR PSR RELAY DID NOT CLOSE OR REOPENED –Indicates the medium or high pressure switch input failed to close on a call for intermediate- or maximum-heat, or opened during a heatcycle. PSR relay may be defective. Refer to status code #3.10 POLARITY – Check for correct line voltage polarity. If units are twinned, check for proper low-voltage (24V) transformer phasing.1 + 2 BLOWER ON AFTER POWER UP – (115 VAC or 24 VAC) – Normal operation. Blower runs for 90 seconds, if unit is powered upduring a call for heat (R-W/W1 closed) or (R-W/W1 opens) during the blower on-delay period.1 + 5 BLOWER MOTOR LOCKOUT – Indicates the blower failed to reach 250 RPM or the blower failed to communicate within 30 secondsafter being turned ON in two successive heating cycles. Control will auto reset after 3 hours. Refer to status code #4 + 1.2 + 5 MODEL SELECTION OR SETUP ERROR – If status code 2 + 5 only flashes 4 times on power-up the control is missing its modelplug PL4 and is defaulting to the model selection stored in memory. If status codes 2 + 5 flashes continuously it could indicate thefollowing:- Model plug PL4 is missing and there is no valid model stored in permanent memory. This will happen if you forget to install themodel plug PL4 on a service replacement control.- Thermostat call with setup switch “SW1-1” ON.- Thermostat call with setup switch “SW1-6” ON.- Setup switch “SW1-1” and “SW1-6” both ON together.- Two different furnace models twinned.- Service replacement control is incorrect. Need modulating board with software version V17 or later.- See rating plate for model plug number and resistance values if code flashes continuously.3 + 5 GAS VALVE FAULT – Indicates the modulating gas valve failed to respond to a command from the furnace control or power to the gasvalve electronics was interrupted. Check for:- Intermittent RED, YELLOW, or ORANGE wire at gas valve or PL8 connections.4 + 1 BLOWER MOTOR FAULT – Indicates the blower failed to reach 250 RPM or the blower failed to communicate within the prescribedtime limits. Thirty seconds after being turned ON or ten seconds during steady-state operation.4 + 2 INDUCER MOTOR FAULT – Indicates the inducer has not started within 20 seconds after a call for heat, the inducer motor RPM isoutside its valid range of operation, or the inducer RPM signal was lost for 5 seconds during operation. Check for:- Proper vent sizing.- Restricted vent.- Failed inducer motor.- Improper motor wiring.- Blockage in the tubing to the pressure switch assembly or blockage in the pressure tap at the collector box.4 + 3 LOW OR MEDIUM PRESSURE SWITCH OPEN WHILE MEDIUM OR HIGH PRESSURE SWITCH IS CLOSED – Checkfor:- Low inlet gas pressure (if LGPS used).- Plugged condensate drain.- Improper pressure switch wiring.- Water in vent piping, possible sagging pipe.- Low or Medium pressure switch stuck open.- Disconnected or obstructed pressure tubing.6 + 1 IGNITION LOCKOUT – Control will auto reset after 3 hours. Refer to status code #6.COMPONENT TESTTo initiate the component test sequence, shut “OFF” the room thermostat or disconnect the “R” thermostat lead. Reset power and then put setupswitch “SW1-6” in the ON position to start the component test sequence. Once initiated the furnace control will turn the inducer ON at mediumspeed. The inducer motor will run for the entire test. The hot surface igniter and blower motor will be turned ON for 15 seconds each. When theblower is turned OFF the inducer will be turned OFF. When the component test is completed one or more of the following codes will flash.LED CODE DESCRIPTIONHEARTBEAT Indicates the inducer motor, gas valve, & blower motor tested OK. Visual check of the hot surface igniter required.2 + 5 SETUP ERROR – Same as code 2 + 5 above.3 + 5 GAS VALVE FAULT – Same as code 3 + 5 above.4 + 1 BLOWER MOTOR FAULT – Indicates blower motor failed test. Check blower, wiring, and furnace control.4 + 2 INDUCER MOTOR FAULT – Indicates inducer motor failed test. Check inducer, wiring, and furnace control.To repeat component test turn setup switch “SW1-6” OFF and then back ON. After component test is completed put setup switch “SW1-6” in theOFF position and reconnect the “R” thermostat lead.440 08 4001 00