Carrier 58TMA Service And Maintenance Instructions

Also see for 58TMA: Install and operation instructions User's information manual User's information manual Installation, start-up, and operating instructions

Contents

troubleshooting

Carrier 58TMA Service And Maintenance Instructions Manual pdf 10 page image

A93386If inducer and burners continue to operate, check for 24v at thegas valve. If 24v are present, verify that the thermostat is openacross R and W. If no voltage is present, turn the gas valvecontrol knob to the OFF position. Replace gas valve.Is indoor blower on ?24v should be present across C and W. If not, check for:1. Open thermostat.2. Open 24-v fuse (FU1) – Code 24.3. Failed transformer.If Code 23 is displayed, the pressure switch(es) is stuck closed.Replace switch and/or check pressure tube for blockage.System malfunction – Code 21.115v should be present at the inducer motor. If so, replace inducermotor. If not, check 115-v wiring.Is Code 31 (high-gas-heat only), 32, 33, or 34 displayed? Checkcode information label to diagnose.Check polarity of 115-v power at J-box and control. Twinnedfurnace polarities must match – rapid flashing LED.Check ground continutity from J-box to control.Check flame sensor microamps (4.0 nominal; 0.5 minimum forcontrol to recognize flame).24v should be present across R and C. If not, check for:1. Open limit switch (LS) – Code 13 or 33.2. Open flame rollout switch (FRS) – Code 13 or 33.24v should not be present across R and G. If so, turn thermostatFAN switch to AUTO.If not, check for:1. Satisfied thermostat.2. Open inlet gas pressure switch (when used).3. Open pressure switch (LPS) – Code 32.4. Open draft safeguard switch (DSS) – Code 32.5. Open auxilliary limit (ALS)(downflow/horizontal only) – Code 32.6. Open 24-v fuse (FU1) – Code 24.7. Open limit switch (LS) – Code 13 or 33.8. Open flame rollout switch (FRS) – Code 13 or 33.9. Check 115-v line voltage – LED off.Check for sources of electrical noise interference (electronic aircleaners, nearby TV, or radio antennas).If Code 32 is displayed check for:1. Open gas inlet pressure switch (when used).2. Open pressure switch (LPS) and/or tube – Code 32.3. Open draft safeguard switch (DSS) – Code 32.4. Open auxiliary switch (ALS)(downflow/horizontal only) – Code 32.5. Check all low-voltage wiring connections.115v should be present at the ignitor. If so, replace the ignitor; if not,check 115-vac wiring to ignitor.LPS, DSS, or ALS open while HPS if closed (high-gas-heat only) –Code 43.Is the gas valve control knob in the OPEN or ON position?24v should be present across the gas valve terminals C and M/P(and C and HI for high-fire test) during the 7 sec ignition trial. Ifnot, check all low-voltage wiring connections to valve.If 24v are present, and main gas does not flow:1. Supply pressure > 13.6-in. wc.2. Replace gas valve.Check ignitor position.Check burner carryover gap.Check gas supply pressure (4.5-in. wc minimum).Check manifold pressure (1.3- to 1.7-in. wc for low-fire; 3.2- to3.8-in. wc for high fire).Check for proper orifice size.Control will attempt to light burners 4 times (approximately 1 minutebetween attempts – Code 34). Voltage is present at the gas valve for 7sec during each ignition trial. System will lockout after 4 attempts.115v should be present at the blower motor. If so, check capacitor.If capacitor is OK, replace blower motor. If 115v are not present atthe blower motor, check all 115-v wiring to motor.Cycle 115-v poweroff for 3 sec, then on.Continuous LED?Draft inducer motor starts.Is Code 22 displayed?15-sec inducer pre-purge.Set thermostat to call for heat.Set FAN switch to AUTO.Turn thermostat OFF.On furnace control, note currentsettings for setup switches 1 (SW-1)and 2 (SW-2) then set SW-1 to OFFand SW-2 to ON.If LED is flashing rapidly, check line voltage polarity.If Code 24 is displayed, check for blown fuse.If LED is OFF, check line voltage and 24-v transformer.If Code 45 is displayed, replace control.TROUBLESHOOTINGGUIDENOTES:WARNINGELECTRICAL SHOCK HAZARDONLY QUALIFIED AND TRAINEDSERVICE PERSONNEL SHOULDPERFORM THIS PROCEDURE!Flame present when not normal.Replace gas valve.Ignitor warms up and glowsorange/yellow; 17-sec warm-up.STARTYesNoYesMain burners ignite.YesNoYesMain burners stay on.Turn thermostat to OFF; gas valveshuts off burners; 5-sec inducerpost purge.Indoor blower motor stops after90, 135, 180, or 225 sec.YesYesFurnace runs until call forheat ends.YesNoNoNoNoNoNoNoIndoor blower motor starts onheating speed after 45-secwarm-up period.NoYesYesYesYesYesNoReplace control only if all checksare OK.NoReplace control only if Code 45 isdisplayed, or if all checks are OK.NoNoReplace control if Code 45 is dis-played, or if all checks are OK.Clean flame sensor if microampsare below nominal.NoReplace control only if Code 45 isdisplayed, or if all checks are OK.NoReplace control only if Code 45 isdisplayed, or if all checks are OK.NoReplace control only if Code 45 isdisplayed, or if all checks are OK.NoReplace control only if Code 45 isdisplayed, or if all checks are OK.NoRefer to information label on blower compartment doorfor procedure for use of LED status codes and problemsolving suggestions.LED indicator is viewed through window on blowercompartment door.If 115-vac power is energized or interrupted during acall for heat, the indoor blower will run for 90 sec beforea gas heating cycle begins – Code 12.After replacing any component, verify correct operatingsequence.1.2.3.4.Heating sequence of operationcomplete. Remove blower door,move setup switch 1 (SW-1) to ONposition and repeat process to checkhigh-fire operation. (When finishedreturn SW-1 and SW-2 to originaldesired settings.)No24v should be present across Rand C. If not, check for:Open flame rollout switch(FRS) – Code 33.Open limit switch (LS) –Code 33.Check all low-voltage wiringconnections.1.2.3.Replace control only if Code 45 isdisplayed, or if all checks are OK.Copyright 1995 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231 58t3smManufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.Book 1 4Tab 6a 8a PC 101 Catalog No. 565-845 Printed in U.S.A. Form 58T-3SM Pg 10 1-95 Replaces: 58T-2SM

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