Carrier 58MVP Troubleshooting Manual

Also see for GAS FURNACE 58MVP: Installation, start-up, and operating instructions User's information manual User manual User's information manual User's information manual

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Carrier 58MVP Troubleshooting Manual Manual pdf 10 page image

NOT ENOUGH COOLING AIRFLOW—Generally, this indicates the Y/Y2 thermostat lead is not properlyconnected.STEP ACTION YES NO GO TO1. Remove blower access panel and depress door switch. Use a piece of tape to hold switch closed.Wait a few sec for self test before proceeding to next step. — — 22. Make sure thermostat is calling for cooling. If thermostat lead G is not connected, jumper acrossthermostat terminals R and G. — — 33. Make sure thermostat fan control is in AUTO position if equipped. — — 44. Do you have 24v across Y/Y2 and Com on furnace control board? 8 5 —5. You have a defective thermostat, or a break in wiring between thermostat and furnace, or the Y/Y2thermostat terminal is not wired to thermostat. — — 66. Fix problem. — — 77. Go to page number indicated in Index for CLEANUP AND START-UP INSTRUCTIONS. — — INDEX8. Are air conditioning select switches A/C set to proper tonnage as required by condensing unit? (SeeTable 1.) 10 9 —9. Set air conditioning select switches A/C for proper tonnage as required by condensing unit. (SeeTable 1.) — — 710. Disconnect the G thermostat lead or jumper if used. — — 1111. Does blower motor turn off in 90 sec when G thermostat lead is disconnected? 12 13 —12. Replace furnace control board. — — 713. Observe operation of furnace in cooling mode for 8 minutes. — — 1414. Does furnace operate properly in cooling mode? 15 16 —15.Make sure outdoor unit is properly charged. If it is, go to page number indicated in Index forCLEANUP AND START-UP INSTRUCTIONS. If problem persists on an intermittent basis, replacefurnace control board. If problem still persists after replacing furnace control board, contact your dis-tributor.— — INDEX16. Does furnace abruptly go through a self-test sequence as blower comes up to speed? 17 24 —17. Do you have less than 17 vac between R and Com on furnace control board? 18 24 —18. Do you have less than 90 vac between P1 and P2 on furnace control board? 19 20 —19. Make sure the wire gage between main fuse box and furnace complies with wire size specificationin Installation, Start-Up, and Operating Instructions. — — 620. Disconnect the R thermostat lead. — — 2121. Do you have less than 17 vac between R and Com on furnace control board? 22 23 —22. Replace transformer. — — 723.Check the thermostat wire gage between furnace and thermostat, and furnace and outdoor unit. It isrecommended that AWG No. 18 color-coded copper thermostat wire be used for lengths up to 100ft. For wire lengths over 100 ft, use AWG No. 16 wire.— — 624. Press down on microprocessor chip and make sure it is properly seated to furnace control board. Ifit is, replace furnace control board. — — 6Table 1—Air Conditioning (A/C) Airflow Setup Switch PositionAIR CONDITIONER(TONS)AIRFLOW(CFM)A/C SWITCH POSITION ALLOWABLE FURNACE MODEL SETUPA/C-1 A/C-2 A/C-3 040 060 080 080 100 120Default 1200 or2000 OFF OFF OFF 3 Tons1200 CFM3 Tons1200 CFM3 Tons1200 CFM5 Tons2000 CFM5 Tons2000 CFM5 Tons2000 CFM1-1/2 600 ON OFF OFF X X X — — —2 800 OFF ON OFF X X X X X X2-1/2 1000 ON ON OFF X X X X X X3 1200 OFF OFF ON X X X X X X3-1/2 1400 ON OFF ON X X X X X X4 1600 OFF ON ON — — — X X X5 2000 ON ON ON — — — X X XX—Indicates allowable selection.10