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IMPROPER COOLING AIR FLOW - - Generally, this indicates the Y/Y2 thermostat lead is
not properly connected.
STEP
1.
Remove blower access panel and depress door switch. Use a piece of tape to hold switch
closed.
2.
Set thermostat to call for cooling. If thermostat does not have G connection jumper across
thermostat terminals R and G.
3.
Make sure thermostat fan control is in the AUTO position if equipped.
4.
Do you have 24- -vac across Y/Y2 and C
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.
Fix the problem.
7.
Go to page number indicated in Index for CLEANUP AND START- -UP INSTRUC-
TIONS.
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.)
9.
Set the air conditioning airflow select switches A/C to the proper airflow as required by the
condensing unit. (See Table 2.)
10.
Disconnect the G thermostat lead or jumper if used.
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.
Replace the variable speed furnace control.
13.
Reconnect the G thermostat lead or jumper and observe operation of furnace in cooling
mode for 10 minutes.
14.
Does the furnace operate properly in cooling mode?
15.
- - Check outdoor unit for correct suction pressure and verify charge.
- - Check filter(s) and ductwork for restrictions.
- - Check furnace coil.
16.
Does the AMBER LED abruptly shut off as the blower comes up to speed?
17.
Do you have less than 17 vac between R and C
trol?
18.
Do you have less than 90 vac between L1 and NEUTRAL- -L2 on the variable speed fur-
nace control?
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.
20.
Disconnect the R thermostat lead.
21.
Do you have less than 17 vac between R and C
trol?
22.
Replace transformer.
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.
24.
Is Status Code 41 flashing?
25.
Go to the page number indicated in the Index for Status Code 41.
26.
- - Check outdoor unit for correct suction pressure and verify charge.
- - Check furnace coil.
ACTION
V on the variable speed furnace control?
OM- - 24
V on the variable speed furnace con-
OM- - 24
V on the variable speed furnace con-
OM- - 24
10
YES
NO
GO TO
2
3
4
8
5
6
7
INDEX
10
9
7
11
12
13
7
14
15
16
INDEX
17
24
18
24
19
20
6
21
22
23
7
6
25
26
INDEX
7
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