Lennox International Inc Lennox Heat Pump Error Codes and Ambient Sensor Problems Explained

System Status, Fault and Lockout LED Codes

LED codes are displayed using various LEDs located on the heat pump control (A175). See figure 16 for locations of heat pump control LEDs.

DS11 AND DS14 ATUS, FAULT AND

LOCKOUT LED CODES

DS11 (Green) and DS14 (Red) LEDs indicate non−communicating mode diagnostics conditions that are listed in table 14.

These LEDs display the most common fault conditions in the system. When an abnormal condition is detected, this function communicates the specific condition through system LED alert codes The function is capable of detecting both mechanical and electrical system problems.

DS15 AND DS13 AULT AND

LOCKOUT LED CODES

DS15 (Yellow) and DS13 (Red) LEDs indicate non−communicating mode diagnostics conditions that are listed in table 15.

These LEDs display the most common fault conditions in the system. When an abnormal condition is detected, this function communicates the specific condition through system LED alert codes The function is capable of detecting both mechanical and electrical system problems.

IMPORTANT

DS15 and DS13 compressor LED fault and lockout codes do not provide safety protection. The is a monitoring function only and cannot control or shut down other devices.

RESETTING FAULT AND LOCKOUT LED CODES

All LED fault and lockout codes can be reset manually or automatically:

1.Manual Reset

Manual reset can be achieve by one of the following methods:

S Disconnecting R wire from the heat pump control’s R terminal.

S Turning the indoor unit off an on again

After power up, existing code will display for 60 seconds and then clear.

2.Automatic Reset

After a fault or lockout is detected, the heat pump control continues to monitor the unit’s system and compressor operations. When/if conditions return to normal, the alert code is turned off automatically.

Table 14. System Status, Fault and Lockout LED Codes and Related icomfort Touch® Thermostat Alert Codes

System fault and lockout LED (DS11 / DS14) alarm codes takes precedence over system status LED codes (cooling, heating stages or defrost/dehumidification).Only the latest active LED fault or lockout alarm code if present will be displayed. If no fault or lockout codes are active, then system status LEDs are routinely displayed. See notes 1 and 2 in table below for duration of fast / slow flashes and pause.

Heat Pump Control			icomfort
	LEDs		Touch®	Condition	Possible Cause(s)	Solution
			Thermostat
DS11		DS14 Red
			Display
Green
					SYSTEM STATUS
					1. No power (24V) to heat
					pump control terminal’s	1 Check control transformer power (24V).
			Not		R and C or heat pump
Off		Off		Power problem		2 If power is available to control and LED(s) do not
					control failure.
			applicable
						light, replace the heat pump control.
					2. Heat pump control
					failure.
Simultaneous slow flash			Not	Normal operation	Unit operating normally or in standby mode.
			applicable

Alternating slow flash

Not

applicable

5−minute anti−short cycle delay

Initial power up, safety trip, end of room thermostat de- mand.

None required (Jumper FIELD TEST (E33) pins to override)

Simultaneous fast

flashes

Moderate /

Critical Alert

Code 180

Ambient sensor problem

If sensor detects an open, shorted or out−of−temperature range. heat pump control will revert to time/temperature defrost operation. System will still heat or cool.

		Moderate /	Coil sensor	If the outdoor coil temperature sensor is detected as being open or shorted, the heat
Alternating fast flash		Critical Alert
			problem	pump control will not perform defrost operations.
		Code 417
On	On	Not	Heat pump	Indicates that heat pump control has an internal component failure. Cycle 24 volt
		applicable	control failure	power to heat pump control. If code does not clear, replace the heat pump control.

Page 40

506586−01 10/10