Page 26
Installer’s Guide
ECM Fan Motor Adjustments
If the airflow needs to be increased or decreased, see the
Airflow Table in the SERVICE FACTS. Information on chang
-
ing the speed of the blower motor is in the Blower Performance
Table. Blower speed changes are made on the ECM Fan Control
mounted in the control box. The ECM Fan Control controls the
variable speed motor. There is a bank of 8 dip switches, (See
Figure 23 below), located on the board. The dip switches work in
pairs to match the cooling/heat airflow (CFM/TON), Fan off-delay
options and electric heat airflow adjustment. The switches ap
-
pear as shown in the Figure below.
Figure 23. ECM Fan Control
6. Remove the manifold retaining screws and pull the burner-
manifold assembly from the heat exchanger.
7. Remove the inlet turbulators being careful not to break or
damage them.
8. Wipe the flue box and flue baffles clean with a clean, dry
cloth.
9. Replace all gaskets with new ones.
10. Replace all damaged or broken turbulators with new ones.
11. Reassemble the unit by reversing Steps 2 through 7 above.
Take care that all gaskets seat properly.
12. Check all wires for correct installation by referring to the
unit’s electrical wiring diagram in the SERVICE FACTS.
13. Leak test all gas line connections with a soap and water
solution or the equivalent.
14. Re-install the CONTROL/HEAT access panels and the flue
hood.
15. Visually inspect the unit to ensure that the airflow opening
for combustion is not obstructed.
16. Follow the start-up procedure on page 22 to place the unit
back in service.
CFM
SELECTION
LIGHT
DIP
SWITCHES
Never use combustible cleaning fluids on any part of the
furnace.
CAUTION
!
Flue Hood and Combustion Blower Cleaning
Before each heating season, the flue should be inspected for
signs of flaking rust and soot deposits.
Dirty flues should
be cleaned by qualified service personnel ONLY
using the
following procedure:
1. Turn the comfort control to
OFF
. Turn the main power
disconnect
OFF
. Turn the manual gas valve
OFF
.
2. Remove the flue hood and the CONTROL/HEAT access
panel.
3. Remove the combustion blower assembly from the flue box.
Remove the flue box and the flue restrictors.
4. Remove all wires from the gas valve while carefully noting
their locations.
5. Disconnect the gas supply line from the valve.
Summary of Contents for 4YCY4024
Page 5: ...Page 5 Installer s Guide Figure 2 4YCY4024 through 4YCY4036 2 of 3...
Page 6: ...Page 6 Installer s Guide Figure 3 4YCY4024 through 4YCY4036 3 of 3...
Page 8: ...Page 8 Installer s Guide Figure 5 4YCY4042 through 4YCY4060 2 of 3...
Page 9: ...Page 9 Installer s Guide Figure 6 4YCY4042 through 4YCY4060 3 of 3...
