Lwco Fault - A.O. Smith DSE-5 Service Handbook

Fault & Alert Messages
DISPLAYED MESSAGE
CONDITION/INDICATES

"LWCO Fault"

(Fault Condition)
The control system has detected a low water
condition in the water heater's storage tank - see
page 47.
Possible Causes:
No water or low water in tank
Water heater/CCB not properly grounded
Plug/socket/wiring connection problems
LWCO probe wiring shorted to ground
Heavy calcium/lime accumulation on LWCO probe
Defective LWCO probe
Servicing should only be performed by a Qualified Service Agent
TROUBLESHOOTING
• Ensure the water heater is full of water. Follow
the filling instructions in the maintenance sec-
tion of Instruction Manual that came with the
water heater.
• Ensure the water heater is properly grounded -
see grounding instructions in the Instruction
Manual that came with the water heater and
Grounding instructions on page 5 in this man-
ual.
• Ensure the CCB is properly grounded - see the
Checking Power And Ground To The CCB tests
on page 54. Ensure the ground wire leading
from pin 2 of the J2 plug on the CCB (page 50)
is securely connected to ground and the wire
was properly stripped and crimped in it's con-
nector.
• Check the J10 plug/socket connection at the
CCB ensure they are mating properly and pro-
viding good contact. See CCB illustration and
socket identification on pages 50 - 52.
• Check for pinched/broken/shorted wiring
between the LWCO probe and the J10 plug/
socket connection on the CCB - repair or
replace damaged wiring as necessary. See
CCB illustration and socket identification on
pages 50 - 52.
• Remove the LWCO probe and inspect for dam-
age and/or heavy calcium/lime accumulation
clean and/or replace the LWCO probe as neces-
sary - see page 47.
• Call the toll free technical support phone num-
ber on the back cover of this manual for further
assistance if the problem has not been cor-
rected after performing the procedures outlined
here.
79
CHECK/REPAIR