10
IMPROPER COOLING AIR FLOW -- Generally, this indicates the Y/Y2 thermostat lead is
not properly connected.
STEP ACTION YES NO GO TO
1. Remove blower access panel and depress door switch. Use a piece of tape to hold switch
closed.
2
2. Set thermostat to call for cooling. If thermostat does not have G connection jumper across
thermostat terminals R and G.
3
3. Make sure thermostat fan control is in the AUTO position if equipped. 4
4. Do you have 24--vac across Y/Y2 and COM--24V on the variable speed furnace control? 8 5
5. You have a defective thermostat, or a break in the wiring between the thermostat and the
furnace, or the Y/Y2 thermostat terminal is not wired to the thermostat.
6
6. Fix the problem. 7
7. Go to page number indicated in Index for CLEANUP AND START--UP INSTRUC-
TIONS.
INDEX
8. Are the air conditioning airflow select switches A/C set to the proper airflow as required by
the condensing unit? Typical airflow is based on 350 CFM/TON (See Table 2.)
10 9
9. Set the air conditioning airflow select switches A/C to the proper airflow as required by the
condensing unit. (See Table 2.)
7
10. Disconnect the G thermostat lead or jumper if used. 11
11. Does the blower motor turn off in 5 seconds when the G thermostat lead is disconnected?
Note: When using a dehumidify--enabled thermostat the blower may change airflow when
the G thermostat lead is disconnected and a call to dehumidify is active.
12 13
12. Replace the variable speed furnace control. 7
13. Reconnect the G thermostat lead or jumper and observe operation of furnace in cooling
mode for 10 minutes.
14
14. Does the furnace operate properly in cooling mode? 15 16
15. -- Check outdoor unit for correct suction pressure and verify charge.
-- Check filter(s) and ductwork for restrictions.
-- Check furnace coil.
INDEX
16. Does the AMBER LED abruptly shut off as the blower comes up to speed? 17 24
17. Do you have less than 17 vac between R and COM--24V on the variable speed furnace con-
trol?
18 24
18. Do you have less than 90 vac between L1 and NEUTRAL--L2 on the variable speed fur-
nace control?
19 20
19. Make sure the wire gage between main fuse box and furnace complies with wire size spe-
cification in Installation, Start--Up, and Operating Instructions.
6
20. Disconnect the R thermostat lead. 21
21. Do you have less than 17 vac between R and COM--24V on the variable speed furnace con-
trol?
22 23
22. Replace transformer. 7
23. Check the thermostat wire gage between furnace and thermostat, and furnace and outdoor
unit. It is recommended that AWG No. 18 color--coded copper thermostat wire be used for
lengths up to 100 ft. For wire lengths over 100 ft, use AWG No. 16 wire.
6
24. Is Status Code 41 flashing? 25 26
25. Go to the page number indicated in the Index for Status Code 41. INDEX
26. -- Check outdoor unit for correct suction pressure and verify charge.
-- Check furnace coil.
7
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