Suburban DynaLine Owner's Manual 04/2021 Rev.4
26
FAULT CODES AND DESCRIPTIONS (
ALL DL3 UNITS)
Fault # Fault Type
Description
Details
2
THERMOSTAT
SENSOR CODE
(read in STANDBY
mode)
Room sensor fault
The display will show “Lo” for an open circuit in sensor or wire and will
show “Hi” for a shorted circuit in sensor or wire. If code 2 occurs, the
Service System Indicator will stay ON until power is cycled.
NOTE:
“Lo” will also display if the room temperature falls below 45°.
“Hi” will also display if the room temperature is above 99°. The unit will
function in HEAT or COOL if there is a thermostat demand.
11
LIMIT SWITCH CODES
(read in Service/HEAT
mode)
Limit open fault
High limit fault code is caused by dirty filter, restricted air flow, low room
blower rpm. Blocked flue fault code is caused by low exhaust blower rpm,
intake or exhaust restriction. The Service System Indicator will be on as
long as the limit switch is open (in all modes).
NOTE:
Ignition will restart as soon as the limit closes.
12
Limit switch lockout
After 15 limit trips (during one thermostat controlled heat cycle), there is
a 60 minute lockout. All unit functions stop during lockout and the Service
System Indicator is activated. The heating cycle resumes after the lockout
period expires and the limit trip counter is reset to zero. The limit trip
count is set to zero each time the thermostat set point is satisfied.
13
PRESSURE SWITCH
CODES
(read in Service/HEAT
mode)
Pressure switch
fault - stuck closed:
(switch contacts
close without
combustion blower
operation)
After the room air blower runs for 15 seconds, a 20 minute lockout period
begins. The code is registered and the Service System Indicator is
activated. Ignition trial recurs after the lockout expires.
14
Pressure switch
contacts “Open”
lockout - failed to
close
The pressure switch contact remain open on start-up of a HEAT cycle.
The exhaust blower cycles 15 seconds ON and 15 seconds OFF. After 5
unsuccessful tries, a 20 minute lockout begins and code 14 is registered.
The room air blower stops and the Service System Indicator is activated.
Ignition trial recurs after the lockout expires.
15
Loss of pressure
switch lockout
Pressure switch contact open during heating operation. After 5 trips of
the pressure switch a 20 minute lockout begins, code 15 is registered
and the Service System Indicator is activated. During the lockout period
the exhaust and room air blowers shut OFF. Ignition trial recurs after the
lockout expires.
16
FLAME SENSOR
CODES
(read in Service/HEAT
mode)
Failed to ignite
lockout
Absence of flame sense during trial for ignition, due to no gas flow, open
circuit CO detector, glow bar failure, or flame probe failure or position.
There is a 20 second post purge between tries for ignition. After three
trials for ignition, fault code 16 is registered and the Service System
Indicator is activated. A 60 minute lockout period starts. The exhaust and
room air blowers shut off. Ignition trial recurs after the lockout expires.
17
Loss of flame
lockout
During heating operation, loss of flame sense, due to gas flow interruption
or flame probe failure. Five trips (during one thermostat controlled heat
cycle) are required to initiate the code and lockout. A 60 minute lockout
period starts. During the lockout period, the exhaust and room air blowers
shut off. Ignition trial recurs after the lockout expires.
18
False flame fault
Flame probe senses flame in the absence of heating operation
(monitored in all unit modes). The exhaust blower is activated and
the room air blower will run on HIGH speed as long as false flame is
indicated. The cooling function is suppressed.
19
GAS VALVE CODE
(read code in Service/
HEAT mode)
False gas valve fault
Indicates a presence of 24 volt power on the gas valve circuit when the
unit is not in the heating mode (monitored in all unit modes). The exhaust
blower is activated and the room air blower will run on HIGH speed as
long a false gas valve is indicated. The cooling function is suppressed.
28
POWER DOWN CODE
(read in Service/COOL
mode)
Power down
Indicated that the power down terminals are energized with 24 VAC due
to an emergency generator signal. Prevents (or stops) the compressor
and condenser fan operation during emergency generator operation. The
Service System Indicator is on during power down when cooling demand
is present. The room air blower will run with cooling demand in the power
down condition.
