Energy Cut Out (Eco) - A.O. Smith DSE-5 Service Handbook

Fault & Alert Messages
DISPLAYED MESSAGE
CONDITION/INDICATES

"Energy Cut Out (ECO)"

(Fault Condition)
The control system has detected excessive water
temperature inside the water heater. The ECO high
temperature limit switch activates at 202°F/94°C.
See ECO High Temperature Limit Switch description
on page 43.
Possible Causes:
Plug/socket connection problems
Wiring connection problems
Contactor(s) stuck closed
Contactor coils being energized in standby mode
Defective Immersion Temperature Probe
Water piping problems
Servicing should only be performed by a Qualified Service Agent
TROUBLESHOOTING
• Check the J5 plug/socket connection at the
CCB ensure they are mating properly and pro-
viding good contact. Check the pins inside the
J5 plug/socket for wear or damage. See CCB
illustration and socket identification on pages 50
- 52. Replace damaged plug connectors/wiring
harness as necessary.
• Check for pinched or broken wiring between the
Immersion Temperature Probe and the J5 plug/
socket connection on the CCB - repair or
replace damaged wiring as necessary. See
CCB illustration and socket identification on
pages 50 - 52.
• Check ECO continuity and for 120 VAC to and
from the ECO - see pages 45 & 46. Replace
Immersion Temperature Probe if ECO switch
contacts remain open at normal operating tem-
peratures.
• Ensure the contactors are not stuck closed - see
page 36.
• Ensure the contactor coils are not being ener-
gized during standby mode - see pages 37 &
38.
• Check water system piping; ensure heat is not
being added to the water heater being serviced
by any other heating appliances or heat
sources.
• 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.
78
CHECK/REPAIR