ICP 9MAC/E series Troubleshooting Manual

Contents

ICP 9MAC/E series Troubleshooting Manual Manual pdf 2 page image

- 2 -You should ALWAYS begin in the START HERE section (seeIndex for page number) which will guide you to the appropriatesection where a minimal number of steps will be used to correct theproblem. Once in a section, read the ACTION. An ACTION mayhave a number in the GO TO column. Do whatever the ACTIONsays, then proceed to the step indicated in the GO TO column.If the ACTION is a question (a question will have a number in theYES or NO column), answer it YES or NO. If the answer is YES, goto the step indicated in the YES column. If the answer is NO, go tothe step indicated in the NO column.Let’s try our guide out using the EXAMPLE section below, and seehow it works. Suppose that the problem is a defective low pressureswitch (for example the contacts will not open). This is an internalproblem and cannot simply be seen. We go to the START HEREsection to Step 1.EXAMPLEStart Here SectionSTEP ACTION YES NO GO TO1. Step 1 tells us NOT TO REMOVE THE BLOWER DOOR. It then asks the question, “IsAMBER LED status light ON SOLID, alternately flashing bright-dim-bright-dim like aheartbeat, or flashing ON and OFF?”. If the low pressure switch was defective, a pressureswitch did not open status code would be flashing, so the answer is YES. We go to Step 2.2 192. Step 2 asks the question, “Is the AMBER LED status light ON SOLID?”. If the low pressureswitch was defective, a pressure switch did not open status code would be flashing, so theanswer is NO. We go to Step 4.3 44. Step 4 asks the question, “Is the AMBER LED status light alternately flashing bright-dim-bright-dim like a heartbeat?”. If the low pressure switch was defective, a pressure switch didnot open status code would be flashing, so the answer is NO. We go to Step 5.7 55. Step 5 tells us to determine the status code. The status code is a single or two digit numberwith the first number determined by the number of short flashes and the second number afterthe (+) sign is the number of long flashes. So we count the short flashes and long flashes ifavailable and see that status code 2 is flashing and go to Step 6.66. Step 6 tells us to go to status code 2 section. INDEXGENERALThe furnace must have a 115-vac power supply properly connectedand grounded. Correct polarity must be maintained to enable gasheating operation.The gas service pressure must not exceed 0.5 psig (14-in.wc), and noless than 0.16 psig (4.5-in.wc).Thermostat wire connections to the furnace at R and W/W1 are theminimum required for gas heating operation. W2 must be connectedfor 2-stage heating thermostats. Y/Y2 and G are required to beconnected to the furnace for single-stage cooling and heat pumps.Y1, Y/Y2, and G are required for two-stage cooling and heat pumps.G is required for continuous-fan. COM-24V is required for someclock thermostats. These connections must be made at the 24-vacterminal block on the furnace control. (See Appendix A)This furnace can be installed with either a single-stage heat/cool or atwo-stage heat/cool thermostat.CAUTION: This furnace is equipped with a manualreset switch in the gas control area. The switch will openand shut off power to the gas valve, if a flame rollout oroverheating condition occurs in the gas control area. DONOT bypass the switch. Correct inadequate combustion-air supply, or component failure before resetting theswitch.Before operating the furnace, check each manual reset switch forcontinuity. If necessary, press and release the button to reset theswitch.SEQUENCE OF OPERATIONUsing the schematic diagram in Appendix A, follow the sequence ofoperation through the different modes. Read and follow the wiringdiagram very carefully!!Note: If a power interruption occurs during a call for heat (W/W1or W/W1-and-W2), the control will start a 90-second blower-onlyON period two seconds after power is restored, if the thermostat isstill calling for gas heating. The amber LED light will flash code 12during the 90-second period, after which the LED will be ONcontinuous, as long as no faults are detected. After the 90-secondperiod, the furnace will respond to the thermostat normally.The blower door must be installed for power to be conducted throughthe blower door interlock switch ILK to the furnace control CPU,transformer TRAN, inducer motor IDM, blower motor BLWM, hot-surface igniter HSI, and gas valve GV.COMMUNICATING CONTROL AND MODULATINGHEATINGBest comfort will be attained when a Communicating Wall Control isused with this product. Wiring and set-up instructions are providedwith the communicating control. See the furnace data sheet accessorysection for help in selecting the appropriate communicating controlfor this furnace.When a communicating control is used, the furnace will modulatethrough its full operation range, or can be limited via the minimumand maximum cfm configurations.Operation of the furnace at the beginning and end of each heatingcycle, will be the same as detailed below in the Single-Stage!440 08 4001 00