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

Page: 39 / 60

25 MAY 2009 Page 39 000744MAN-02
HYDRONIC TROUBLE SHOOTING - AQUASTAT
Fault Possible Cause Verification Recommended Action
No display on
aquastat.
Call for heating or cooling
from thermostat Verify thermostat. None, this is normal operation.
Blown Primary or Secon-
dary fuse on transformer. Visually inspect. Remove fuse and
check for continuity if in doubt. Replace fuse.
Blown fuse on control
board. Visually inspect. Remove fuse and
check for continuity if in doubt. Replace fuse.
Faulty transformer 230VAC is present across L1 and L3
of the compressor contactor but
24VAC is not present across R and
C. Replace transformer.
Faulty wiring between
heat pump and aquastats. 24VAC is not present across 24V and
COM at the top of the aquastat. Correct the wiring.
Faulty aquastat. 24VAC is present across 24Vand
COM of the aquastat but there is no
display. Replace aquastat.
Incorrect aquastat setup. Aquastat does not indicate S1 on the
display. Correct the setup.
No YA signal to
DXTF Control
Box
Faulty aquastat to DXTF
Control Box wiring. 24VAC not present across Stage 1 C
and COM of the aquastat. Correct or replace wiring.
Faulty aquastat to DXTF
Control Box wiring. 24VAC signal present across Stage 1
NO and COM of the aquastat but not
present across YA and CA of the
DXTF Control Box terminal strip. Correct or replace wiring.
Faulty aquastat.
No 24VAC between Stage 1 NO and
COM of the aquastat when S1 is indi-
cated on the aquastat display. Replace aquastat.
No BA signal to
DXTF Control
Box Incorrect aquastat setup. Aquastat does not indicate S2 on the
display. Correct the setup.
Faulty aquastat to DXTF
Control Box wiring. 24VAC not present across Stage 2 C
and COM of the aquastat. Correct or replace wiring.
Faulty aquastat to DXTF
Control Box wiring. 24VAC signal present across Stage 2
NO and COM of the aquastat but not
present across BA and CA of the
DXTF Control box terminal strip. Correct or replace wiring.
Faulty aquastat.
No 24VAC between Stage 2 NO and
COM of the aquastat when S2 is indi-
cated on the aquastat display. Replace aquastat.
Setting(s) not
retained Faulty aquastat E2 error message. Can cause the
unit to trip a safety control if the set-
ting is too high or low. Replace aquastat.