Product Manual

13
BASIC TROUBLESHOOTING
Fault
Code
Fault name
Possible causes
Possible Outcome
Reset method
F23
No heat
- element burned out
- ECO tripped/malfunctioning
- interrupted triac
- relay/contactor
malfunctioning
- board failure
- inlet thermistor interrupted
- heater stops until the
fault is cleared
- causing condition
disappears
F24
Low heat
- severe undervoltage
- triac failure
- partial board failure
- partial inlet/outlet
thermistors failure
- heater keeps running
while displaying the fault
code
- manual fault clear or
causing condition
disappears
F33
Shorted triac
- both triacs (triac) failed to
full conduction mode
- heater stops
functioning
- fault cleared only by
power cycling
F34
Overvoltage
- voltage too high compared to
the specified value
- unit will cease to
function
- manual fault clear
F36
Undervoltage
- voltage too low compared to
the specified value
- unit keeps functioning
while displaying the
warning message
- causing condition
disappears
F38
High flow
- flow is too high for the unit
to be able to keep up with
heating water to setpoint
temperature
- Fault code displayed,
unit continues to
operate
- reduce flow below
maximum limit for the
current heater parameters
F47
Inlet
thermistor
failure
- inlet thermistor interrupted
or disconnected
- heater will run based
on outlet detected
temperature
- causing condition
disappears
F48
Outlet
thermistor
failure
- outlet thermistor interrupted
or disconnected
- heater will run based
on inlet temperature
and flow
- causing condition
disappears
F64
Freeze
protect
- inlet temperature too low
- partial inlet thermistor failure
- heater will not run
- causing condition
disappears
F83
Inverted flow
- water flows through the
heater in the wrong direction
- unit will cease to
function
- causing condition
disappears