Tranquility
®
D i g i t a l ( D X M 2 ) — Tr o u b l e s h o o t i n g G u i d e
R e v. : 1 0 M a r c h , 2 0 1 5
20
G e o t h e r m a l H e a t i n g a n d C o o l i n g
Fault
Htg Clg Possible Cause
Solution
Main Power Problems
X
X
Green status LED off
Check Line Voltage circuit breaker and disconnect
between 197-254 volts
Check for line voltage between L1 and L2 on the contactor
Check for 24VAC between R and C on DXM 18-31.5
Check primary/secondary voltage on transformer
HP Fault Code 2
X
Reduced or no water flow
Check pump operation or valve operation/setting
in cooling
Check water flow adjust to proper flow rate
X
Water t emperature out of range in
cooling
Bring water temp within design parameters.
Water is too warm.
X
Reduced or no air flow
Check for dirty air filter and clean or replace
in heating
Check fan motor operation and airflow restrictions
Dirty air coil- construction dust etc.
Too high of external static. Check static vs blower table
X
Air t emperature out of range in
heating
Bring return air temp within design parameters
X
X
Overcharged with refrigerant
Check superheat/subcooling vs typical operating condition
table
X
X
Bad HP switch
Check switch continuity and operation - Replace
LP/LOC Fault-Code 3
X
X
Insufficient charge
Check for refrigerant leaks
Low Pressure/
Loss of Charge
X
Compressor pump down at start-
up
Check charge and start-up water flow
LT1 Fault - Code 4
X
Reduced or no water flow
Check pump operation or water valve operation/setting
Water Low Temperature
in heating
Plugged strainer or filter - clean or replace
Check water flow adjust to proper flow rate
X
Inadequate anti-freeze level
Check antifreeze specific gravity with hydrometer. See A-R.
X
Improper low temperature setting
(30°F vs 10°F)
Clip JW3 (LT1) jumper for antifreeze use. Be sure loop
has 15º freeze protection
X
Water t emperature out of range
Bring water temp within design parameters
X
X
Bad thermistor
Check temp and impedance correlation per chart
LT2 Fault - Code 5
Low Air Temperature
X
Reduced or no air flow
Check for dirty air filter and clean or replace
in cooling
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
X
Air temperature out of range
Too much cold vent air. Bring entering air temp within
design parameters that IOM specifies.
X
Improper low temperature setting
(30°F vs 10°F)
Normal airside applications will require. Only setting for
packaged units is 30º.
X
X
Bad thermistor
Check temp and impedance correlation per chart
Condensate Fault -
Code 6 High
Condensate Level
X
X
Blocked drain
Check for blockage and clean drain
X
X
Improper trap
Check trap dimensions and location ahead of vent
X
Poor drainage
Check for piping slope away from unit
Check slope of unit toward outlet
Poor venting - check vent location
X
Moisture on sensor
Check for moisture shorting to air coil
Over/Under Voltage -
Code 7
X
X
Under voltage
Check power supply and 24VAC voltage before and during
operation
(Auto Resetting)
Check power supply wire size
Check compressor starting. Need hard start kit?
Check 24VAC and unit transformer tap for correct power
supply voltage. See A-W.
X
X
Over voltage
Check power supply voltage and 24VAC before and during
operation.
Check 24VAC and unit transformer tap for correct power
supply voltage
Unit Performance
Sentinel-Code 8
X
Heating Mode LT2>125°F
Check for poor air flow or overcharged unit
X
Cooling Mode LT1>125°F OR
LT2< 40°F
Check for poor water flow, or air flow
No Fault Code Shown
X
X
No compressor operation
See 'Only Fan Operates'
X
X
Compressor overload
Check and replace if necessary
X
X
Control board
Reset power and check operation
Unit Short Cycles
Check Thermostat
Location and
Anticipation Setting
X
X
Dirty air filter
Check and clean air filte r
X
X
Unit in 'Test Mode'
Reset power or wait 20 minutes for auto exit
X
X
Unit selection
Unit may be oversized for space - check sizing for actual
load of space
X
X
Compressor overload
Check and replace if necessary
Only Fan Runs
X
X
Thermostat position
Insure thermostat set for heating or cooling operation
X
X
Unit locked out
Check for lockout codes - reset power
X
X
Compressor overload
Check compressor overload - replace if necessary
X
X
Thermostat wiring
Check thermostat wiring at DXM2 - put in Test Mode and
Swapped Thermistor
Code 9
X
X
LT1 and LT2 swapped
Reverse position of thermistors
ESD - ERV Fault
(DXM Only)
Green Status
LED Code 3
X
X
ERV unit has fault
(Rooftop units only)
Troubleshoot ERV unit fault
jumper Y1 and R to give call for compressor
X
X
Plugged air filter
X
X
Restricted return air flow
Replace air filter
Find and eliminate rectriction - increase return duct and/or
grille size. Check static pressure. See the diagram on B-D.
ECM Fault -
Code 10
X
X
Blower does not operate
Check blower line voltage. See B-I.
Check blower low voltage wiring
Blower operating with incorrect
airflow
Wrong unit size selection
Wrong unit family selection
Wrong motor size
Incorrect blower selection
Low Air Coil
Pressure Fault
(ClimaDry) Code 11
X
Reduced or no air flow in cooling
or ClimaDry
Low Air Coil
Temperature Fault -
(ClimaDry) Code 12
X
Reduced airflow in cooling,
ClimaDry, or constant fan
Air temperature out of range
Check switch continuity and operation - replace
Bad pressure switch
Air temperature out of range
Bad thermistor
Check temp and impedance correlation per chart
IFC Fault Code 13
Internal Flow
Controller Fault
X
X
No pump output signal
Check DC voltage between A02 and GND - should be
between 0.5 and 10 VDC with pump active. See A-J.
Low pump voltage
Check line voltage to the pump. See picture A-O.
No pump feedback signal
Check DC voltage between T1 and GND. Voltage should
be between 3 and 4 VDC with pump OFF, and between
0 and 2 VDC with the pump ON. See A-B.
Bad pump RPM sensor
Replace pump if the line voltage and control signals are
present at the pump, and the pump does not operate
Fault
Htg Clg Possible Cause
Solution
Check for dirty air filter and clean or replace
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
Too much cold vent air - bring entering air temp within
design parameters
Check for dirty air filter and clean or replace
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
Too much cold vent air - bring entering air temp within
design parameters
High Pressure
X
Frozen water heat exchanger
Thaw heat exchanger (water pressure switches).
X
X
Bad HPWS Switch
Replace HPWS Switch. See B-A.
Commercial
Only
Functional Troubleshooting
A-F
