Maritime Geothermal TF-45, Installation And Service Manual

Page: 48 / 89

Page 48 001223MAN-05 1-Jul-2017
FAULT CODE TROUBLESHOOTING
Fault Possible Cause Verification Recommended Action
Fault Code 1
(High Pressure
Control)
High operating refrigerant
pressure
Using a refrigeration gauge set, verify
that high pressure approaches or ex-
ceeds 565psi with compressor on.
See “High Discharge Pressure” in
Heating Mode / Cooling Mode Trou-
bleshooting section.
Faulty High Pressure Control
(open).
* For this test there must be a
signal present on Y1, but
compressor should not be
running (disconnect com-
pressor power plug).
Verify that there is 24VAC across HPS
(right terminal) on the control board and
C of the terminal strip, as well as HPS
(left terminal) and C.
Replace high pressure control if volt-
age is present on one terminal but
not the other.
Faulty control board. 24VAC is present across HPS (right ter-
minal) and C of the terminal strip, as well
as HPS (left terminal) and C, but is not
present across CC on the control board
and C after 10 minutes.
Replace control board.
Fault Code 2
(Low Pressure
Control)
Low operating refrigerant
pressure
Using a refrigeration gauge set, verify
that low pressure approaches or dips
below 55psi (ground loop) or 75 psi
(open loop) with compressor on.
See “Low Discharge Pressure” in
Heating Mode / Cooling Mode Trou-
bleshooting section.
Faulty Low pressure control
(open).
* For this test there must be a
signal present on Y1, but
compressor should not be
running (disconnect com-
pressor power plug).
Verify if there is 24VAC across LPS on
the control board and C of the terminal
strip, as well as HPS (left terminal) and
C.
Replace high pressure control if volt-
age is present on one terminal but
not the other.
Faulty control board. 24VAC is present across LPS and C of
the terminal strip, as well as HPS (left
terminal) and C, but is not present
across CC on the control board and C
after 10 minutes.
Replace control board.
Little or no refrigerant in unit. With compressor off, use a refrigeration
gauge set to check refrigeration pres-
sure of the unit for a very low value (less
than 100 psi).
Locate the leak and repair it. Spray
9, a sniffer, and dye are common
methods of locating a leak.
Fault Code 4
(Condensate
overflow)
Condensate overflow. Drip tray under air coil is full of water up
to the terminals of the condensate sen-
sor.
Locate blockage or other cause of
drain problem and rectify.
Fault Code 5
(Brownout)
Low voltage from the electri-
cal grid.
Verify that the electrical supply has
dropped below ~165VAC, causing trans-
former voltage to drop below 18VAC.
Contact electrical utility or wait for
regular service to be restored.
THERMOSTAT TROUBLESHOOTING
Fault Possible Cause Verification Recommended Action
No Y1 signal to
heat pump
(after 6 minutes)
Incorrect thermostat setup. Thermostat does not indicate a call for
heat. No 24VAC signal present across
Y1 & C of the thermostat
Correct the setup.
Faulty thermostat to heat
pump wiring.
24VAC signal present across Y1 & C of
the thermostat but not present across Y1
& C of the terminal strip.
Correct or replace wiring
Faulty thermostat. No 24VAC between Y1 & C of the ther-
mostat when a call is indicated.
Replace thermostat.