Troubleshooting - York T2GY Installer's Manual

T2GY INSTALLER'S GUIDE

Troubleshooting

Standard Microprocessor Controls
To check the unit control board for proper operation:
1. Disconnect thermostat wires at the control board.
2. Jumper the desired test input (Y1, Y2, W, O or G) to the R terminal to simulate a thermostat signal. To simulate a hot
water call, jumper tan wires 11 and 14 on P5 connector.
3. If control functions properly:
• Check for thermostat and field control wiring (use the diagnostic inputs mode).
4. If control responds improperly:
• Ensure that component being controlled is functioning (compressor, blower, reversing valve, etc.).
• Ensure that wiring from control to the component is functioning (refer to the LED Definition table below and use
the diagnostic outputs mode).
• If steps above check properly, replace unit control.
LED Definitions and Diagnostics
Standard Microprocessor
NORMAL
LED
DISPLAY MODE
Field Selection
DIPS
SW2-
SW2-
SW2-
Drain Pan Overflow
Drain
Lockout
FD Thermistor
(Loop <15º F,
Water Flow
Well<30ºF) Lock-
out
High Pressure
High
>600
Pressure
PSI Lockout
Low Low Pressure <40
Pressure PSI Lockout
ECM RPM <100
Airflow
RPM
Microprocessor
Status
Malfunction
DHW Limit Not Used
DHW Off Hot-Water Disable
Refrigerant Systems
To maintain sealed circuit integrity, do not install service gauges unless unit operation appears abnormal. Compare the
change in temperature on the air side as well as the water side to the information found in the Operation Parameters
tables. If the unit's performance is not within the ranges listed, and the airflow and water flow are known to be correct,
gauges should then be installed and superheat and subcooling numbers calculated. If superheat and subcooling are outside
recommended ranges, an adjustment to the refrigerant charge may be necessary.
NOTE: Refrigerant tests must be made with hot water generator turned "OFF". Verify that air and water flow rates are at
proper levels before servicing the refrigerant circuit.
CURRENT
FAULT STATUS
1 On SW2- 1 Off
6 On SW2- 6 On
7 On SW2- 7 On
Drain Pan Overflow
FD Thermistor
(Loop <15º F,
Well<30ºF)
High Pressure
>600
Low Pressure <40
ECM RPM
<100 RPM
Not Used
Not Used
HW Off
DIAGNOSTIC MODES
INPUTS
SW2- 1 NA SW2-
SW2- 6 Off SW2-
SW2- 7 On SW2-
Compressor
Y1
(On or Low)
Compressor
Y2
(On or High)
O Reversing Valve
G
W
SL1 Loop Pump(s)
HW
HW Off
38
OUTPUTS 1 OUTPUTS 2
1 NA SW2-
6 On SW2-
7 Off SW2-
Blower
Blower
Medium
Blower
Blower Aux Heat 1
HW Pump Aux Heat 2
Aux Heat 3
DV Aux Heat 4
HW Off HW Off
1 NA
6 Off
7 Off
Low
High