
Troubleshooting Guide -
Tranquility®
Digital (DXM2) Packaged Units
Rev.: 01/15/14
16 Geothermal Heat Pump Systems
Reversing Valve Touch Test Chart
4
2
3
1
65
Line to
Air Coil
Discharge from
Compressor
Line to
Coax
Suction Line
to Compressor
A-E
VALVE
OPERATING
CONDITION
NOTES: * Temperature of Valve Body
** Warmer than Valve Body
1234 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 flow 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 sufficient 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.