Integrated Control - Lennox MERIT Series Installation Instructions Manual

Integrated Control

TERMINAL DESIGNATIONS
HUM -Humidifier (120VAC)
Line - Input (120VAC)
XFMR - Transformer (120VAC)
EAC - Indoor Air Accessory (120VAC)
Park 1 - Dead terminal for alternate speed tap
Park 2 - Dead terminal for alternate speed tap
FIGURE 55
TABLE 13
Diagnostic Codes Red LED
LED Off No power to control or control hard-
ware fault detected.
LED On
Normal operation.
1 Flash Flame present with gas valve de-en-
ergized.
2 Flashes
Pressure switch closed with combus-
tion air inducer de-energized.
3 Flashes Low-fire pressure, rollout or limit
switch open.
4 Flashes
Primary limit switch open.
5 Flashes Not used
6 Flashes Pressure switch cycle lockout.
7 Flashes
Lockout, burners fail to light.
8 Flashes
Lockout, burners lost flame too many
times.
9 Flashes Line voltage polarity incorrect.
Troubleshooting
Make the following visual checks before troubleshooting:
1 - Check to see that the power to the furnace and the
integrated ignition/blower control is ON.
2 - The manual shutoff valves in the gas line to the
furnace must be open.
3 - Make sure all wiring connections are secure.
4 - Review the Sequence of Operation.
Start the system by setting thermostat above room tem-
perature. Observe system response. Then use the infor-
mation provided in this section to check the system oper-
ation.
The furnace has a built-in, self-diagnostic capability. If a
system problem occurs, a fault code is shown by a red
LED on the control. The control continuously monitors its
own operation and the operation of the system. If a failure
occurs, the LED will indicate the failure code. The flash
codes are presented in TABLE 13.
Fault Code History Button
The control stores the last five fault codes in memory. A
pushbutton switch is located on the control. When the
pushbutton switch is pressed and released, the control
flashes the stored fault codes. The most recent fault code
is flashed first; the oldest fault code is flashed last. To
clear the fault code history, press and hold the pushbutton
switch in for more than 5 seconds before releasing.
High Heat State LED
A green LED is provided on the control board to indicate
high heat state (see TABLE 14).
CFM LED
An amber LED is provided on the control board to display
CFM. To determine what CFM the motor is delivering at
any time, count the number of times the amber LED flash-
es. Each flash signifies 100 CFM; count the flashes and
multiply by 100 to determine the actual CFM delivered (for
example: 5 flashes x 100 = 500 CFM).
High Heat State Green LED
LED Status
LED Off
LED On
LED Flashing
Page 41
TABLE 14
DESCRIPTION
No demand for high heat
High heat demand, operating normally
High heat demand, high pressure switch
not closed