American Dream Ultra Performance Geothermal Copper Series, Installation And Service Manual

Page: 37 / 60

25 MAY 2009 Page 37 000744MAN-02
AIR OPERATION TROUBLESHOOTING - COOLING MODE
Fault Possible Cause Verification Recommended Action
Cooling TXV adjusted too
far open. Verify superheat. It should be be-
tween 8-12°F (3-6°C). Superheat
will be low if TXV is open too far. Adjust TXV to obtain 8-12°F
(3-6°C) superheat.
High Suction
Pressure
(may appear to
not be pumping)
Cooling TXV stuck open. Adjusting the TXV does not affect
the superheat or the suction pres-
sure. Low super heat and dis-
charge pressure.
Adjust the TXV all the way in and out a
few times to loosen it. Replace TXV if
this does not work.
Leaking reversing valve. Reversing valve is the same tem-
perature on both ends of body,
common suction line is warm, com-
pressor is running hot. Replace reversing valve.
Leaking reclaim valve. Scavenger line remains hot where
it enters the common suction line. Replace reclaim valve.
Low Suction
Pressure
Air Flow
See Fan Troubleshooting section.
Note: low airflow will cause the air
coil to ice up once the suction
drops below
90PSIG .
Correct the problem.
Cooling TXV stuck almost
closed or partially blocked
by foreign object. Adjusting the TXV does not affect
the superheat or the suction pres-
sure. TXV may be frosting up. Adjust the TXV all the way in and out a
few times to loosen it. Replace TXV if
this does not work.
Low or no refrigerant
charge. Entering air temperature and air-
flow are good but suction is low.
Check static refrigeration pressure
of unit for very low value. Locate the leak and repair it.
Spray nine, a sniffer and dye are
common methods of locating a
leak.
Leaking cooling check
valve Unit operates correctly when loop is
in use. Loop lines get cold when
loop not in use instead of warming
to ambient, compressor frosts up. Identify the check valve. Try
switching modes a few times. Re-
place if problem continues.
Faulty NO solenoid valve
coil. Verify solenoid by removing it from
the shaft while the unit is running.
There should be an audible click
sound if the solenoid is working. Replace solenoid if faulty.
Faulty NO solenoid valve. A click can be heard when the coil
is energized. Unused loops stay
cold instead of gradually warming
to ambient. Compressor frosts up.
Replace NO valve.
Faulty compressor, not
pumping. Pressures change only slightly from
static values when compressor is
started. Replace compressor.
Compressor
frosting up See Low Suction
Pressure in this section.
TXV frosting up TXV stuck almost closed
or partially blocked by for-
eign object. Adjusting the TXV does not affect
the superheat or the suction pres-
sure.
Adjust the TXV all the way in and out a
few times to loosen it. Replace TXV if
this does not work.
Random Low
Pressure trip
(does not occur
while there) Faulty compressor
contactor. Points pitted or burned. Contactor
sometimes sticks causing the com-
pressor to run without the fan, trip-
ping the low pressure control. Replace contactor.
Intermittent fan. See Fan Troubleshooting section. Correct the problem.