Sequence Of Operation - York P4UCB30N12206 Installation Instruction

650.64-N4
CAUTION: Label all wires prior to disconnection
when servicing controls. Wiring errors can cause
improper and dangerous operation.
The following visual checks should be made before trou-
bleshooting:
1. Check to see that the power to the furnace and the 50E47
control module 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.
12
Start the system by setting the thermostat above room tem-
perature. Observe the system's response. Then use the Trou-
bleshooting Table on page 16 to check the system's operation.
Use the table by reading the upper left-hand box and then
following the instructions in each box. If the condition described
in the box is true (yes answer), go down to the next box. If the
condition is not true (no answer), go to the box to the right.
C
ntinue checking and answering the questions in the
o
boxes until the problem is explained and corrective ac-
tion is described. After any maintenance or repair, the
troubleshooting sequence can be repeated until normal system
operation is obtained.
WARNING: Do not try to repair controls. Replace
defective controls with UPG Source 1 Parts.
Unitary Products Group