ClimateMaster Tranquility Digital DXM2 User manual

DIGITAL Geothermal
Heat Pumps
TE/TZ/TES/TEP
97B0601N01
Rev.: 3/10/15
Tranquility®Digital (DXM2)
Troubleshooting Guide
Table of Contents
Introduction 2
Troubleshooting Flow Chart 3-9
Flow Chart Reference Symbols and Diagrams 10
Contactor Chart 12
Verifying Pump Feedback Signal 12
Removing Powerhead on Modulating Valve 13-14
Checking Compressors 15-16
Reversing Valve Touch Test Chart 17
Performance Troubleshooting 17-18
Functional Troubleshooting 20-22
Typical Split Water-to-Air Troubleshooting Form 23
Typical Water Source Refrigeration Circuit 24
(Heating Cycle)
Unit Operating Conditions 25
Basic Refrigeration Summary 26
Refrigeration Troubleshooting 27-28
Auxiliary Heat Check 29
Checking Pump Output 29
Compressor Contactor Voltage Check 30
Check CCH for 24 Volts 30
Verifying Contactor 30
Verifying Capacitor 31
Checking Pump Power Cord 31
Replacing Variable-Speed Pump Power Head 32
Verifying Power at Molded Plug 32
for Compressor
Verifying Antifreeze 33
Second Stage Verication 34
Verifying 24V at Reversing Valve 35
Checking Reversing Valve at DXM2 35
A0-2 Jumper 36
Checking for Power at DXM2 36
Verifying DC Voltage on DXM2 Board 37
for Modulating Valve Check
TXV Bulb Test 38
Verifying Dipswitch Position 39
Replacing High Pressure Water Switch 39
Verifying a Thermistor 40-41
Turning Breaker on in Panel or Aux Heat Control 42
Static Pressure Check 42
Locating Tstat Version and DXM2 Version 43
UltraCheck EZ™Motor Diagnostic Tool 43
Checking Dipswitches on DXM2 44
Magnet Test to Shift Reversing Valve 44
Checking Blower Line Voltage 45
Modulating Valve Loses Conguration 45
Hard Reset of Thermostat 46
Units Having LT1 Lockouts In Heating 47
Electrical—Power Wiring 48
LT2 Sensor Location for Non-TAH Air Handlers 49
Air Coil Connection 49
Lineset Diameters and Charge Information 49
Connection to Non-Communicating thermostat and
AXM communicating control in TAH Air Handler 50
Connection to Non-Communicating thermostat
and non-communicating Air Handler/Furnace 50
Denitions of Conditions 51-52
DXM2 Board Layout and Dipswitches 53
AXM Board Layout and Dipswitches 54
DXM2 Controls 55-58
Typical Wiring Diagrams 59-61
ATC32U02 Thermostat Screens and Set Up 62-68
Revision History 72

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
2Geothermal Heating and Cooling
Troubleshooting ClimateMaster Tranquility®Digital Packaged Heat Pumps is quite straightforward.
Most problems relate to water ow. Either there isn’t enough water ow or the entering water temperature is improperly
supplied. Most service problems can be addressed without refrigerant gauges. In fact, installing gauges on packaged heat
pumps can do more harm than good because packaged heat pumps contain less refrigerant compared to split systems.
The rst thing to do is always perform a water side check (Heat of Extraction for Heating or Heat of Rejection for Cooling) to
determine if the unit is operating properly.
Set up and diagnostics are made easier using the communicating thermostat (ATC32) or the communicating service tool
(ACDU02). You must have ATC32 or ACDU02 to properly work on ClimateMaster Tranquility® Digital units that use the DXM2
control board.
Follow the ow chart on the following pages to help diagnose and solve your issue.
Introduction

3
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Troubleshooting Flow Chart
Did unit
start?
Check that unit
voltage reads:
197-254V
Does thermostat say
‘No Communication’?
The unit did
start but it
locked out
Establish power
Check that the
compressor is not in a
thermal overload
Check Fault Code
from thermostat
or service tool
No Yes
Verify that
Dipswitch 1
on S3
is in ‘On’
position
Is there power
to DXM2 24V?
(18-31.5V)
A-W
A-Z
No
Fault
See Fault Codes
and Possible
Causes
A-F
Check that there
are 24 volts at CC on
DXM2 board and a call
for heating or cooling
A-K
Check for 24V at
contactor
18-31.5 volts
A-M
No
Replace the
DXM2 Board
Check and possibly
replace wiring
No
No
Yes Yes
Next Page
Yes
Yes
No A-A
If it is still not
communicating,
check the
thermostat wire
(Be sure it is not
running parallel
along power
wire). Ensure all
wiring is landed
properly on
both DXM2 and
thermostat.
Replace board if
current board still
does not function
Disconnect and
reconnect the
wires from the
DXM2. This
will reset the
thermostat.
Verify that
the DXM2’s
dipswitches
are set
properly.
Is the unit
properly
congured?
See Section
3.0 on page
56.
B-G
Hard
reset the
thermostat
B-K
Hook Service Tool up to
board. Does Service Tool
communicate with board?
Also ensure there
are no wire nuts;
solder wires if
they need to be
extended.
No

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
4Geothermal Heating and Cooling
See Section 3.2
on page 56.
Troubleshooting Flow Chart
My unit has
a Modulating
Valve. Is valve
opening?
Is the valve having
trouble shutting
completely and/or
is the unit
locking out?
No
Continued
Yes
Check
What are the ∆T set points?
Control defaults are 7°
heating and 10° cooling.
Open loop units with EWT
less than 50° will need
to lower ∆T to 4-5° in the
heating mode.
Valve opens or
closes correctly
Yes
Verify A0-2
jumper is in
10V position.
A-V
Be sure unit
is congured
for Modulating
Valve.
Verify Valve and
powerhead
alignment
Manually open the valve
100%. Remove powerhead
from valve with powerhead
still energized. Then verify that
the notches on valve body are
in the correct position.
Third notch aimed down in
unit position.
Then reattach powerhead.
A-C
Next Page
Replace pump
power head
No
Is there voltage
to the pump?
(197-254V)
A-O
The unit starts
but the pump
does not
Check that the
A0-2 jumper on
DXM2 board is in
PWM position
Yes
A-V
Yes
Replace
wire harness
Yes
Yes
No
No
A-P
Check DC Voltage
at DXM2 Board
A0-2-Ground = .5-10 VDC
Is voltage in this range?
Does the low
voltage wiring
have a broken
wire?
Check DC Voltage
at DXM2 Board
T1-Ground = 3-4 VDC
(Pump off)
0-2 VDC
(Pump on)
Is voltage in this range?
No
Replace
DXM2 board
A-J
Yes
No
Yes
Verify how the units are
congured in the thermostat
(refer to ‘Section 3.3 - Unit
Conguration’ on page 53).
Be sure unit is congured for
‘Variable Speed Pump Single’
if unit is on it’s own loop. If unit
shares a loop with other units,
then ensure that the unit is
congured for ‘Variable Speed
Pump Parallel.’
B-L
Pump may be
locked. Pull
pump motor.
Can you free
impeller?
Replace pump
motor

5
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
No
Yes
Replace wire
harness
No
Continued
Troubleshooting Flow Chart
Verify in
conguration
that the unit
is congured
correctly for ECM
Yes
Check continuity on
communicating harness
from DXM2 to Module.
Is there a broken wire?
No
Is 197-254V at the
blower motor?
Check the wire
harness and
replace if needed
Replace
defective part
Next Page
Does blower
turn on?
Verify that
the wiring on
the valve and
DXM2 Board
are correct.
See wiring
diagrams on
pages 53-54.
Valve does
function but
when the unit
shuts off, the
valve remains
open.
Verify that the DC voltage on DXM2
between A0-2 and GND. Voltage should
be between 3.3-10VDC. This is the output
from the board to the valve.
Verify 3/4” Valve Dipswitch
or 1” Valve Dial
A-X
A-C
Yes
B-I
The unit uses
a modulating
valve but the
thermostat
continues
to show a
variable-
speed pump.
Connect a piece of thermostat wire
between T1 and GND on DXM2 so the
DXM2 board sees no feedback.
B-J
No
No
Check DC voltage on
DXM2 on packaged
or AXM on split with
communicating harness
to blower connected 12V–
GND should read 9–15V
Does the motor try to spin
when giving a ‘G’ call?
Use Emerson EZ Tool to
troubleshoot motor and
verify motor or module
B-F
B-M

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
6Geothermal Heating and Cooling
Replace
defective
wiring
No
Verify that
Dipswitch 1:4
is on
No
Call for
cooling
Unit starts but
does not shift
to cooling
Continued
Verify that
you have
cooling
call at
thermostat
No
Yes
Check
reversing valve
connection at
DXM2. Do you
have 24 VAC?
Yes
A-U
Verify
24V at
reversing
valve
Yes Replace
solenoid on
reversing valve
Yes
In order to increase pressure
and move a reversing valve
that is sticking, place unit
in heating mode and then
remove blower door. Just after
removing door, energize the
valve. If it still doesn’t shift, try
a strong magnet to pull over
internal slide while energizing.
A-T
B-H Verify RV
operation
Replace the reversing valve if
it still does not shift
Next Page
If Dipswitch 1:4
is on, replace
board
A-E
Troubleshooting Flow Chart
There are
no faults,
but does the
compressor
start?
Verify comp contactor.
Verify capacitor. Turn off
power and allow 5 minutes
for discharge. Then verify
with volt meter the UF
reading compare to UF
reading on capacitor. Is
capacitor good?
No
A-N
Replace capacitor.
No
Yes Verify voltage to
compressor at
molded plug
Replace molded
plug and wire
harness
A-Q
Turn power off and
remove molded plug on
compressor. Measure
resistance between C-S
and C-R.
Replace compressor
A-D
Yes
A-A
Yes
No
Yes
Yes
Is the
blower loud?
Check your
model’s airow
conguration.
See Section 3.1
on page 56.
Check static
pressure
B-D
No
Verify that
all grilles
and registers
are open.

7
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Verify whether
the thermostat
is congured
for multi-stage
operation
No
Unit does
not seem to
be in second
stage. This is
indicated by the
performance
check being
about 30%
(low).
Verify that
you have
second
stage call
Does
DXM2
CCH have
24V?
Verify that
Dipswitch
1:4 is on
No
A-L
Yes Yes Yes Does the rectier
plug on the side
of the compressor
have 15-27 VDC?
Replace the
rectier plug
No
With unit running in second
stage, check amp draw
of comp. Next, remove
rectier plug. Amps should
be lower after removing
plug. Reattach plug and
verify that amps return to
previous higher reading.
Yes
A-S
Replace
compressor
No
Continued
The unit started
but runs and
loop temp
continue to drop
in the heating
mode
Yes
Verify the antifreeze
level where applicable.
Remember that EWT
below 45° needs 15° or
lower freeze protection.
Verify with appropriate
hydrometer.
A-R
Yes
Antifreeze has
been veried
as having 15°
or lower freeze
protection.
Then cut the
JW3 jumper
Yes
Is there enough loop in
the ground? Is the loop
making good contact?
(Example: Is your
vertical loop grouted
from top to bottom?)
Is the loop turbulent?
Min 2500 Reynolds
Number.
Yes
Next Page
Use Pressure Drop
Software to verify
If Dipswitch 1:4
is on, replace
board
Troubleshooting Flow Chart
No
No

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
8Geothermal Heating and Cooling
Continued
Congure
No
See Lockout
Faults on page
51 under ‘Fault
Codes’
Is there more
than one unit
sharing a
common loop?
No
Properly congure
unit. See Section 3.3
and Section 3.4 on
page 57.
Does this unit
have a Variable
Speed Pump and
is it congured for
parallel pumping?
No
Yes Yes Yes
Is the thermostat
congured for the proper
model of the unit?
(Example: TZ036) This is
found on thermostat’s unit
conguration menu.
Yes Yes
Does the unit have the
correct ECM Motor? Check
the ECM table, which is in
the unit’s IOM.Compare to
the motor in the unit.
Verify pump is
supplying enough ow
using Pressure Drop
Software. Closed loop
2.25 - 3.0 gpm per ton.
Replace with
correct motor
No
The unit
periodically
locks out on LT1
in heating or
high pressure in
cooling
ATC Thermostat
says ‘ECM
Conguration
Error’
The unit does
run but ATC
Thermostat
says ‘Service
Needed’
Yes
Troubleshooting Flow Chart
This is the Unit
Performance Sentinel. In
cooling mode if LT2 is 40°
or lower or LT1 is 125° or
greater. In heating mode if
LT2 is 125° or greater.
Go to Faults
Code 8.
A-F
Next Page
No
No
No

9
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Replace
DXM2 or AXM
No
Unit runs but
does not satisfy
Yes Yes
The unit is running.
However, there is
a load issue. The
home is losing or
gaining more than
the capacity of the
heat pump.
If water ow and airow are good,
then verify refrigerant charge.
Calculate superheat and subcooling.
A-H
Troubleshooting Flow Chart
Continued
The unit runs
but auxiliary
heat is not
working
Yes Is the thermostat
calling for
auxiliary heat or
emergency heat?
Verify that
conguration is set
to auxiliary heat in
thermostat. See
section 2.2.2 on
page 55.
No
Does unit have
197-254V at
auxiliary heat
strip?
Turn breaker
on in panel or
in auxiliary heat
control
B-C
No
Yes Yes
Replace
wire harness
No
Does the heat
strip control
board have the
same 24 VDC as
the DXM2?
Yes
Replace heat
strap board
Yes
Verify the Water Side
Performance
HE = Heat Extraction in
BTUs (Heating)
HR = Heat Rejection in
BTUs (Cooling)
Calculate using the formula
found on A-G.
Check with performance
data. Is unit within 10%?
A-G
Verify load using a
manual J program.
You may also need to
perform a blower door
test for true inltration
and thermal imaging
for locating heat loss.
Also consider a duct
blast to verify that
air is being delivered
properly.
Yes
Adjust charge if needed to proper
superheat and subcooling ranges.
No
No
Then check for proper TXV operation
before adding or removing charge.
A-Y
Does DXM2 or
AXM (splits) have
24 VDC at EH1
and/or EH2?
A-I

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
10 Geothermal Heating and Cooling
Notes: Specific to Splits
1. When using TES/TEP with communicating Air Handlers
(and not using ATC32U02 Thermostat using a 24 volt
stat) you must mount stat at Air Handler or unit. For
proper communicating between TES/
TEP, an Air Handler, ATC32U02 should be
placed in the OFF position when not using
it as a service tool.
2. When conguring TES or TEP after a board change
be sure of correct blower type. Select NONE on tool or
thermostat because there is no blower directly connected
to the DXM2.
3. TAH Air Handlers can be changed to operate blower on
115 volts instead of 230 volts. Be sure NOT
to connect the supplied jumper to other
opp. molex plug unless you truly want 115
volts.
4. When installing LT2 Sensor on cased coil or other manu-
facturer Air Handler, be sure it is installed between TXV
and distributor tubes. If you can not install
the sensor in that location then do not in-
stall the sensor any where else on the coil
and leave jumper on DXM2 board.
5. Ensure that TXV bulb is strapped outside of
the Air Handler or Cased Coil on the suction
line and that the TXV bulb is insulated.
6. All TES/TEP units come factory charged for an additional
25 feet of lineset. Be sure to add or subtract from this
based on your lineset length. Final verica-
tion is looking at superheat and subcooling
numbers against operating parameters in
IOM.
7. On AXM in TAH Air Handler, the only dipswitch used is
#2, which can be used for dehumidication. On the AXM,
“ON” is Normal and “OFF” is Dehumidication.
8. When brazing a lineset, use Nitrogen ow to prevent
oxidation and carbon build up, because these things can
restrict the TXVs. Also, protect service valves with a wet
rag or heat block to prevent overheating and causing
damage. Always install a biow lter drier in lineset.
9. For reference connecting low voltage wiring
when using other Air Handlers or gas
furnace in duel fuel applications, see B-S.
B-R
B-N
B-O
B-P
B-Q
B-S

11
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Reference Symbols and Diagrams
for Flow Chart

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
12 Geothermal Heating and Cooling
Verifying Pump Feedback Signal
A-B
Contactor Chart
A-A
Contactor Chart
Contactor
closed
Motor does
not hum
Burned
contacts
Open in low
voltage circuit
Incorrect
wiring
Open motor
wiring
Open overload
switch
Motor hums, cuts off
on overload circuit
breaker or blows
fuses
Compressor tight or
stuck
High discharge
pressure not
equalized
Low line
voltage
Burnt out or
open winding
Non-condensibles in
refrigerant circuit
Contactor open
Buzzing
Check
contactor
Normal voltage
to coil
Contactor defective,
jammed or hung up
Low voltage
to coil
Wrong gauge of
thermostat wire
Low voltage from
transformer
Not buzzing
Loose
wire
No voltage
to coil
No power
to control circuit
Voltage
to coil
Coil open
circuited
P1
Alarm
Relay
Comp
Relay
O
Y1 Y2
W
G
C R
AL1
24Vdc
EH1
EH2
P6
R C
Off On
JW3
A
OVR
ESD
C R
NSB
AL2
JW1
Acc1
Relay
Acc2
Relay
H
COM
NC1
NO1
COM
NC2
NO2
P3
CO
RV RV
LT1 LT1 LT2 LT2
LP LP
HP HP
P7
Status
Fault
R R
CC
CCG
CO
S1
S2
1
12
1 4
Factory Use
(240Vac)
Com
N.O.
Fan Enable
5 1/2"
7" 6 1/2"
5"
Use 4 mounting screws
#6 sheet metal screw 1” long
1.5
3/8” standoff
Factory low
voltage molex
connection for
unit harness
Factory low
voltage molex
connection for
electric heat
harness
Micro
U1
Off On
P2
COH
COM
AO2
P11
Gnd T1
P10
T2 T2 T3 T3 T4 T4 T5
P9
T5
T6 T6
A0-1 A0-2
Off On
S3
RV
Relay
CCH
Relay
Test
P5
B-
Gnd
P4
A+ 24V
(240Vac)
Fan Speed
N.O.
N.C.
12V
OUT
Gnd
P8
IN
NC
P12
Note: There is only
one T1 connection
1 2 3 4
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
AO1
Gnd
0-2 VDC with pump on
3-4 VDC with pump off
Ensure correct wiring on T1=Yellow,
A0-2=White. If not, voltage may look
good but pump may not operate.

13
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
On 3/4” valve, be sure that dip switch
is moved up or toward center of
valve and valve closes.
For Proper Valve-to-Head Alignment
Before removing power head, go
to manual mode and open valve to
100%. Stay on that screen and with
the valve powered open, remove
power head. Verify or rotate physical
valve to the position.
Open
Closed
Removing Powerhead on ¾-Inch Modulating Valve
A-C

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
14 Geothermal Heating and Cooling
Removing Powerhead on 1-Inch Modulating Valve
A-C
2) The 1-inch valve includes
a tool to remove the
power head.
See previous page for
proper valve-to-head
alignment.
Open
Closed
1) Rotate dial to ‘1’ on the
1-Inch valve.

15
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Checking Compressors
A-D
Compressor C-S
Ohms
C-R
Ohms Unit
ZPS20 1.64 1.30 TZ024, TE026 TEP/TES026
ZPS30 1.52 0.88 TZ036, TE038 TEP/TES038
ZPS40 1.86 0.52 TZ048, TE049 TEP/TES049
ZPS51 1.68 0.41 TZ060, TE064 TEP/TES064
ZPS60 1.85 0.34 TE072
ZPS26 1.90 1.02 TZ030
ZPS35 1.55 0.62 TZ042
Note: Readings are good ± 7%
Note: Reading S-R = C-S + C-R Readings
Example: ZPS20 S-R = 2.94 Ohms
Compressor Ohms Table
Overload opens
R
S
C
Suction
Line
R
S
C
R
S
C
R
S
C
Compressor with Open Internal Overload
If both R and S are open to
common, Internal overload
is open.
Overload opens
R
S
C
Suction
Line
R
S
C
R
S
C
R
S
C
Open run winding (innite)
resistance. Start winding shows
measurable resistance.
Overload opens
R
S
C
Suction
Line
R
S
C
R
S
C
R
S
C
Note: If not, O resistance will
be close to it.
C-S and C-R will have high
resistance above 3 ohms.
Overload opens
R
S
C
Suction
Line
R
S
C
R
S
C
R
S
C
Check for ground by placing
one lead on suction line.
Compressor with Open Run Winding
Compressor with Shorted Windings Compressor Winding Shorted to Ground

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
16 Geothermal Heating and Cooling
An Alternative Way of Checking Compressors
A-D
Megohm Values of Copeland Compressors
For years servicemen have used megohmeters to evaluate
compressor motor windings. However, most megohmeter
manufacturers publish guidelines that apply to open motors.
For this reason, Emerson Climate Technologies has
investigated the use of megohmeters on hermetic and semi-
hermetic compressors.
When using megohmeters to evaluate the motor insulation
of compressors, it is important to understand that they
should not be used as one would a volt-ohm meter. A single
megohmeter reading gives little insight into the condition of a
motor’s insulation.
Megohmeters are best used as a part of a regular
maintenance program to monitor trends (over several
months). For example, one might record a megohm value
and compare it to a previous reading. If subsequent readings
show a trend of lower and lower values, then corrective
action (such as system clean up) should be taken.
Emerson does not incorporate the megohmeter into any of
its quality checks. All Copeland® compressors must pass
U.L. required tests using hi-potential current leakage testers
(“hi-pot”). Studies performed by Emerson have found that
compressors with megohmeter readings as low as 0.5
megohms still pass the hi-pot.
There are many factors that affect megohm readings
including contaminated refrigerant, oil level, refrigerant in
oil and current leakage through electrical fusites or terminal
plates.
Any external electrical components connected to the
compressor terminals also affect megohm readings. Wires,
contactors and relays all leak current and will decrease
compressor megohmeter readings if not disconnected.
As mentioned earlier a single megohm reading cannot be
used to condemn a compressor since many other factors are
involved. However, limits can be placed on megohm values
that dictate action be taken. Emerson has found that these
limits are related to the rated voltage of the compressor.
Megohm values equal to or greater than 1000 ohms per volt
are probably acceptable. For example, a 460 volt compressor
might show a megohm reading of 460,000 ohms or 0.46
megohm. Compressors with rated voltages of 208 to 230
volts would then be operable at megohm values of 0.208 to
0.230 megohms; for simplicity, Emerson has set the limit at
0.5 megohms before a compressor is condemned. Figure 1
shows the required procedure for checking compressors with
a megohmeter.
New compressors that have never been installed will not
need any system clean-up procedures so long as the
megohm reading is above 0.5. A baseline reading must be
established for comparison purposes and since this is its  rst
reading this will be its baseline value.
Megohmmeter
2
© 2010 Emerson Climate Technologies
Printed in the U.S.A.
AE4-1294
Application Engineering
BULLETIN
Figure 1
Megohmeter Test Procedure
B1A8102012450

17
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Reversing Valve Touch Test Chart
A-E
4
2
3
1
65
Line to
Air Coil
Discharge from
Compressor
Line to
Coax
Suction Line
to Compressor
VALVE
OPERATING
CONDITION
NOTES: * Temperature of Valve Body
** Warmer than Valve Body
12 3 4 5 6
NORMAL OPERATION OF VALVE
Normal
COOLING Hot Cool Cool 23 (2)
Hot
23 (7) TVB *TVB
Normal
HEATING Hot Cool Hot 23 (1)
Cool
23 (2) TVB *TVB
MALFUNCTION OF VALVE Possible causes Corrections
Valve will not
shift from heat
to cool
Check electrical circuit and coil
No Voltage to coil Repair electrical circuit
Defective coil (No resistance) Replace coil
Check refrigeration charge
Low charge Repair leak, recharge system
Pressure differential too high Recheck system
Hot Cool Hot
23 (1)
Cool
23 (2) Hot *TVB
Pilot valve okay. Dirt in one bleeder hose. Deenergize solenoid, raise head pressure and reenergize
solenoid to break dirt loose. If unsuccessful, remove
valve and clean out. Check on air before installing if not
movement, reduce valve, add strainer to decharge tube and
mount valve horizontally
Platon cup leak Stop unit. After pressure equalizes, restart with solenoid
energized. If valve shifts, restart with compressor running. If
still no shift, replace valve.
Hot Cool Hot
23 (1)
Cool
23 (2) Hot *TVB Clogged pipe tubes. Raise head pressure, operate solenoid to free. If still no shift,
replace valve
Hot Cool Hot
23 (1)
Cool
23 (2) Hot Hot Both parts of pilot open. (Back seat port did not
close)
Raise head pressure, operate solenoid to free partially
clogged port. If still no shift, replace valve.
Warm Cool Warm
23 (1)
Cool
23 (2) Warm TVB Defective compressor
Start to shift
but does not
complete
reversal
Hot Warm Warm Hot *TVB Hot
Not enough pressure differential at start of
stroke or not enough ow to maintain pressure
differential.
Check unit for correct operating pressures and charge.
Raise head pressure. If no shift, use valve with smaller ports.
Body damage. Replace valves.
Hot Warm Warm Hot Hot Hot Both parts of pilot open. Raise head pressure, operate solenoid. If no shift, replace
valve.
Hot Hot Hot Hot *TVB Hot
Body damage. Replace valve.
Valve hung up at mid-stroke. Pumping volume of
compressor not sufcient to maintain reversal.
Raise head pressure, operate solenoid. If no shift, use valve
with smaller ports.
Hot Hot Hot Hot Hot Hot Both parts of pilot open. Raise head pressure. Operate solenoid. If no shift, replace
valve.
Apparent lock
in cooling
Hot Cool Cool
23 (2)
Hot
23 (1) **WVB *TVB Pilot needle on end of side leaking. Operate valve several times then recheck. If excessive leak,
replace valve.
Hot Cool Cool
23 (2)
Hot
23 (1) **WVB **WVB Pilot needle and piston needle leaking Operate valve several times then recheck. If excessive leak,
replace valve.
Will not shift
cool to heat
Hot Cool Cool
23 (2)
Hot
23 (1) TVB TVB
Pressure differential too high Stop unit. Will reverse during equalization period. Recheck
system.
Clogged pilot tube Raise head pressure. Operate solenoid to free dirt. If still no
shift, replace valve.
Hot Cool Cool
23 (2)
Hot
23 (1) TVB Hot
Dirt in bleeder hole Raise head pressure. Operate solenoid. Replace valve.
Piston cup leak
Stop unit. After pressures equalize, restart with solenoid
deenergized. If valve shifts, reattempt with compressor
running. If it still will not reverse while running, replace valve.
Hot Cool Cool
23 (2)
Hot
25 (1) Hot Hot Defective pilot. Replace valve.
Warm Cool Cool
23 (2)
Warm
25 (1) *TVB Warm Defective compressor.

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
18 Geothermal Heating and Cooling
Symptom Htg Clg Possible Cause Solution
Insufficient Capacity/
Not Cooling
or Heating Properly
XXDirty filter Replace or clean
Rduced or no air flow Check for dirty air filter and clean or replace
in heating Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
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.
See B-D.
XXLeaky duct work
Check supply and return air temperatures at the unit and at
distant duct registers if significantly different, duct leaks
are present. Have a duct blast test performed.
XXLow refrigerant charge Check superheat and subcooling per chart
XXRestricted metering device Check superheat and subcooling per chart - replace if
restriction. Both SH and SC will be high.
XDefective reversing va lve Perform RV touch test
XXThermostat improperly located Check location and for air drafts behind stat
XXUnit undersized Recheck loads & sizing check sensible clg load and heat
pump capacity
XXScaling in water heat exchanger Perform Scaling check and clean if necessary
XXInlet water too hot or cold Check load, loop sizing, loop backfill, ground moisture.
High Head
Pressure
XReduced or no air flow
Check for dirty air filter and clean or replace
in heating
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table.
See B-D.
XReduced or no water flow Check pump operation or valve operation/setting
in cooling Check water flow adjust to proper flow rate
XInlet w ater too hot Check load, loop sizing, loop backfill, ground moisture
XAir temperature out of range in
heatingBring return air temp within design parameters
XScaling in water heat exchanger Perform Scaling check and clean if necessary
XXUnit over charged Check superheat and subcooling - reweigh in charge
XXNon-condensables insystem Vacuum system and reweigh in charge. Vacuum to min
500 microns.
XXRestricted metering device Check superheat and subcooling per chart - replace
Low Suction
Pressure
XReduced water flow Check pump operation or water valve operation/setting
in heating Plugged strainer or filter - clean or replace
Check water flow adjust to proper flow rate. Pump or
value ∆T.
XWater temperature out of range Bring water temp within design parameters
XReduced 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
XAir temperature out of range Too much cold vent air - bring entering air temp within
design parameters
XXInsufficient charge Check for refrigerant leaks
Low Dischage
Air Temperature
in Heating
XToo high of air flow Check fan motor speed selection and airflow chart
XPoor performance See “Insufficient Capacity”
High Humidity
XToo high of air flow Check fan motor speed selection and airflow chart.
Return air temp may be too low.
XUnit oversized Recheck loads and sizing check sensible clg load and
heat pump capacity
Only Compressor
Runs
XXThermostat wiringCheck G wiring at heat pump. Jumper G and R for fan
operation.
XXFan motor relay
Jumper G and R for fan operation. Check for Line voltage
across blower relay contacts.
Check fan power enable relay operation (if present)
XXFan motor Check for line voltage at motor. Check capacitor
XXThermostat wiringCheck thermostat wiring at or DXM2. Put in Test Mode
and then jumper Y1 and W1 to R to give call for fan,
compressor and electric heat.
Unit Doesn't
Operate in Cooling
XReversing Valve
Set for cooling demand and check 24VAC on RV coil.
If RV is stuck, run high pressure up by reducing water flow
and while operating engage and disengage RV coil voltage
to push valve.
XThermostat setup
XThermostat wiringCheck O wiring at heat pump. DXM2 requires call for
compressor to get RV coil “Click.”
X
X
Modulating Valve
Troubleshooting
X
Improper output setting Verify the AO-2 jumper is in the 0-10V position
No valve operation Check voltage to the valve
XNo valve output signal Check DC voltage between AO2 and GND. Should be 0
when valve is off and between 3.3v and 10v when valve
is on.
Replace valve if voltage and control signals are present at
the valve and it does not operate
For DXM2 check for “O” RV setup not “B” if uses conv stat.
Performance Troubleshooting
A-F

19
Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
www.climatemaster.com
Performance Troubleshooting
A-F
Symptom Htg Clg Possible Cause Solution
Insufficient Capacity/
Not Cooling
or Heating Properly
XXDirty filter Replace or clean
Rduced or no air flow Check for dirty air filter and clean or replace
in heating Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
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.
See B-D.
XXLeaky duct work
Check supply and return air temperatures at the unit and at
distant duct registers if significantly different, duct leaks
are present. Have a duct blast test performed.
XXLow refrigerant charge Check superheat and subcooling per chart
XXRestricted metering device Check superheat and subcooling per chart - replace if
restriction. Both SH and SC will be high.
XDefective reversing va lve Perform RV touch test
XXThermostat improperly located Check location and for air drafts behind stat
XXUnit undersized Recheck loads & sizing check sensible clg load and heat
pump capacity
XXScaling in water heat exchanger Perform Scaling check and clean if necessary
XXInlet water too hot or cold Check load, loop sizing, loop backfill, ground moisture.
High Head
Pressure
XReduced or no air flow
Check for dirty air filter and clean or replace
in heating
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table.
See B-D.
XReduced or no water flow Check pump operation or valve operation/setting
in cooling Check water flow adjust to proper flow rate
XInlet w ater too hot Check load, loop sizing, loop backfill, ground moisture
XAir temperature out of range in
heatingBring return air temp within design parameters
XScaling in water heat exchanger Perform Scaling check and clean if necessary
XXUnit over charged Check superheat and subcooling - reweigh in charge
XXNon-condensables insystem Vacuum system and reweigh in charge. Vacuum to min
500 microns.
XXRestricted metering device Check superheat and subcooling per chart - replace
Low Suction
Pressure
XReduced water flow Check pump operation or water valve operation/setting
in heating Plugged strainer or filter - clean or replace
Check water flow adjust to proper flow rate. Pump or
value ∆T.
XWater temperature out of range Bring water temp within design parameters
XReduced 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
XAir temperature out of range Too much cold vent air - bring entering air temp within
design parameters
XXInsufficient charge Check for refrigerant leaks
Low Dischage
Air Temperature
in Heating
XToo high of air flow Check fan motor speed selection and airflow chart
XPoor performance See “Insufficient Capacity”
High Humidity
XToo high of air flow Check fan motor speed selection and airflow chart.
Return air temp may be too low.
XUnit oversized Recheck loads and sizing check sensible clg load and
heat pump capacity
Only Compressor
Runs
XXThermostat wiringCheck G wiring at heat pump. Jumper G and R for fan
operation.
XXFan motor relay
Jumper G and R for fan operation. Check for Line voltage
across blower relay contacts.
Check fan power enable relay operation (if present)
XXFan motor Check for line voltage at motor. Check capacitor
XXThermostat wiringCheck thermostat wiring at or DXM2. Put in Test Mode
and then jumper Y1 and W1 to R to give call for fan,
compressor and electric heat.
Unit Doesn't
Operate in Cooling
XReversing Valve
Set for cooling demand and check 24VAC on RV coil.
If RV is stuck, run high pressure up by reducing water flow
and while operating engage and disengage RV coil voltage
to push valve.
XThermostat setup
XThermostat wiringCheck O wiring at heat pump. DXM2 requires call for
compressor to get RV coil “Click.”
X
X
Modulating Valve
Troubleshooting
X
Improper output setting Verify the AO-2 jumper is in the 0-10V position
No valve operation Check voltage to the valve
XNo valve output signal Check DC voltage between AO2 and GND. Should be 0
when valve is off and between 3.3v and 10v when valve
is on.
Replace valve if voltage and control signals are present at
the valve and it does not operate
For DXM2 check for “O” RV setup not “B” if uses conv stat.
Symptom Htg Clg Possible Cause Solution
Insufficient Capacity/
Not Cooling
or Heating Properly
XXDirty filter Replace or clean
Rduced or no air flow Check for dirty air filter and clean or replace
in heating Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
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.
See B-D.
XXLeaky duct work
Check supply and return air temperatures at the unit and at
distant duct registers if significantly different, duct leaks
are present. Have a duct blast test performed.
XXLow refrigerant charge Check superheat and subcooling per chart
XXRestricted metering device Check superheat and subcooling per chart - replace if
restriction. Both SH and SC will be high.
XDefective reversing va lve Perform RV touch test
XXThermostat improperly located Check location and for air drafts behind stat
XXUnit undersized Recheck loads & sizing check sensible clg load and heat
pump capacity
XXScaling in water heat exchanger Perform Scaling check and clean if necessary
XXInlet water too hot or cold Check load, loop sizing, loop backfill, ground moisture.
High Head
Pressure
XReduced or no air flow
Check for dirty air filter and clean or replace
in heating
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table.
See B-D.
XReduced or no water flow Check pump operation or valve operation/setting
in cooling Check water flow adjust to proper flow rate
XInlet w ater too hot Check load, loop sizing, loop backfill, ground moisture
XAir temperature out of range in
heatingBring return air temp within design parameters
XScaling in water heat exchanger Perform Scaling check and clean if necessary
XXUnit over charged Check superheat and subcooling - reweigh in charge
XXNon-condensables insystem Vacuum system and reweigh in charge. Vacuum to min
500 microns.
XXRestricted metering device Check superheat and subcooling per chart - replace
Low Suction
Pressure
XReduced water flow Check pump operation or water valve operation/setting
in heating Plugged strainer or filter - clean or replace
Check water flow adjust to proper flow rate. Pump or
value ∆T.
XWater temperature out of range Bring water temp within design parameters
XReduced 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
XAir temperature out of range Too much cold vent air - bring entering air temp within
design parameters
XXInsufficient charge Check for refrigerant leaks
Low Dischage
Air Temperature
in Heating
XToo high of air flow Check fan motor speed selection and airflow chart
XPoor performance See “Insufficient Capacity”
High Humidity
XToo high of air flow Check fan motor speed selection and airflow chart.
Return air temp may be too low.
XUnit oversized Recheck loads and sizing check sensible clg load and
heat pump capacity
Only Compressor
Runs
XXThermostat wiringCheck G wiring at heat pump. Jumper G and R for fan
operation.
XXFan motor relay
Jumper G and R for fan operation. Check for Line voltage
across blower relay contacts.
Check fan power enable relay operation (if present)
XXFan motor Check for line voltage at motor. Check capacitor
XXThermostat wiringCheck thermostat wiring at or DXM2. Put in Test Mode
and then jumper Y1 and W1 to R to give call for fan,
compressor and electric heat.
Unit Doesn't
Operate in Cooling
XReversing Valve
Set for cooling demand and check 24VAC on RV coil.
If RV is stuck, run high pressure up by reducing water flow
and while operating engage and disengage RV coil voltage
to push valve.
XThermostat setup
XThermostat wiringCheck O wiring at heat pump. DXM2 requires call for
compressor to get RV coil “Click.”
X
X
Modulating Valve
Troubleshooting
X
Improper output setting Verify the AO-2 jumper is in the 0-10V position
No valve operation Check voltage to the valve
XNo valve output signal Check DC voltage between AO2 and GND. Should be 0
when valve is off and between 3.3v and 10v when valve
is on.
Replace valve if voltage and control signals are present at
the valve and it does not operate
For DXM2 check for “O” RV setup not “B” if uses conv stat.

Tranquility® Digital (DXM2)—Troubleshooting Guide
Rev.: 10 March, 2015
20 Geothermal Heating and Cooling
Fault HtgClg Possible Cause Solution
Main Power Problems XXGreen 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
XReduced or no water flow Check pump operation or valve operation/setting
in cooling Check water flow adjust to proper flow rate
XWater t emperature out of range in
cooling
Bring water temp within design parameters.
Water is too warm.
XReduced 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
XAir t emperature out of range in
heating Bring return air temp within design parameters
XX
Overcharged with refrigerant Check superheat/subcooling vs typical operating condition
table
XX
Bad HP switch Check switch continuity and operation - Replace
LP/LOC Fault-Code 3XXInsufficient charge Check for refrigerant leaks
Low Pressure/
Loss of Charge XCompressor pump down at start-
up Check charge and start-up water flow
LT1 Fault - Code 4
XReduced 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.
XImproper low temperature setting
(30°F vs 10°F)
Clip JW3 (LT1) jumper for antifreeze use. Be sure loop
has 15º freeze protection
XWater t emperature out of range Bring water temp within design parameters
XXBad thermistor Check temp and impedance correlation per chart
LT2 Fault - Code 5
Low Air Temperature
XReduced 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
XAir temperature out of range Too much cold vent air. Bring entering air temp within
design parameters that IOM specifies.
XImproper low temperature setting
(30°F vs 10°F)
Normal airside applications will require. Only setting for
packaged units is 30º.
XXBad thermistor Check temp and impedance correlation per chart
Condensate Fault -
Code 6 High
Condensate Level
XXBlocked drain Check for blockage and clean drain
XXImproper trap Check trap dimensions and location ahead of vent
XPoor drainage
Check for piping slope away from unit
Check slope of unit toward outlet
Poor venting - check vent location
XMoisture on sensor Check for moisture shorting to air coil
Over/Under Voltage -
Code 7
XXUnder 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.
XXOver 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
XHeating Mode LT2>125°F Check for poor air flow or overcharged unit
XCooling Mode LT1>125°F OR
LT2< 40°F Check for poor water flow, or air flow
No Fault Code Shown
XXNo compressor operation See 'Only Fan Operates'
XXCompressor overload Check and replace if necessary
XXControl boardReset power and check operation
Unit Short Cycles
Check Thermostat
Location and
Anticipation Setting
XXDirty air filter Check and clean air filte r
XXUnit in 'Test Mode' Reset power or wait 20 minutes for auto exit
XXUnit selection Unit may be oversized for space - check sizing for actual
load of space
XXCompressor overload Check and replace if necessary
Only Fan Runs
XXThermostat position Insure thermostat set for heating or cooling operation
XXUnit locked out Check for lockout codes - reset power
XXCompressor overload Check compressor overload - replace if necessary
XXThermostat wiring Check thermostat wiring at DXM2 - put in Test Mode and
Swapped Thermistor
Code 9 XXLT1 and LT2 swapped Reverse position of thermistors
ESD - ERV Fault
(DXM Only)
Green Status
LED Code 3
XX
ERV unit has fault
(Rooftop units only) Troubleshoot ERV unit fault
jumper Y1 and R to give call for compressor
XX
Plugged air filter
XXRestricted 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
XXBlower 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
XReduced or no air flow in cooling
or ClimaDry
Low Air Coil
Temperature Fault -
(ClimaDry) Code 12
XReduced airflow in cooling,
ClimaDry, or constant fan
Air temperature out of range
Check switch continuity and operation - replaceBad pressure switch
Air temperature out of range
Bad thermistor Check temp and impedance correlation per chart
IFC Fault Code 13
Internal Flow
Controller Fault
XX 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 HtgC
lg 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
XFrozen water heat exchanger Thaw heat exchanger (water pressure switches).
XXBad HPWS Switch Replace HPWS Switch. See B-A.
Commercial
Only
Functional Troubleshooting
A-F