13
5) TROUBLESHOOTING
CAUTION: Make certain power to unit is “OFF” before removing protective cover FOR ANY REASON.
For status resolution, please consult the table below.
LED Pattern
Status/Problem
Possible causes
Heater response
Possible solutions
Solid light
Heating
N/A
N/A
N/A
One flash every
four seconds
Idle
N/A
- unit waits for
flow
N/A
Two flashes
once, three
second pause
Low heat
- outlet temperature below
90°F/32°C for 5 seconds of
flow
- element failure
- ECO tripped/malfunctioning
- relay/contactor
malfunctioning
- control board failure
- inlet water supply out of
spec
- unit keeps
running, LED
flashes a warning
pattern
- reduce flow
through unit
Two flashes
twice, three
second pause
Outlet thermistor
failure
- outlet thermistor
interrupted or disconnected
- unit keeps
running, LED
flashes a warning
pattern
- inspect
connections/wiring
of outlet
thermistor
Two flashes
three times,
three second
pause
Over-temperature
Warning
- outlet temperature exceeds
110°F/38°C
- unit keeps
running, LED
flashes a warning
pattern
-increase flow
through unit. If this
temperature is
desired no action is
required
Three flashes
once, three
second pause
Over-temperature
Protection
- outlet temperature exceeds
130°F/54
°
C
- unit stops
heating until
outlet
temperature falls
below preset
minimum
- increase flow
through unit to
decrease the
overall
temperature rise
Three flashes
twice, three
second pause
Freeze warning
- inlet temperature is too low
(below 35°F/2°C)
- unit shuts
down*
- increase
temperature of
inlet water to meet
product
specifications
Notes:
* “shut down” means the control board stops applying heat to the heating element, but the control board and
diagnostic functions remain active
Still having trouble? Please call our Technical Service Department.
