11
Troubleshooting
FAULT DESCRIPTION
INDICATIONS
POSSIBLE CAUSE OF FAULT
OPERATIONS TO BE PERFORMED
Water is not
heated
DHW LED on
primary circuit shut-off valves closed
open the valves
modulating valve actuator connector disconnected
reconnect actuator connector
modulating valve actuator disconnected from valve body
reconnect actuator
modulating valve actuator faulty
call qualified personnel to have it replaced
pump not working
call qualified personnel to have it replaced
pump cable not connected
restore connection
presence of air in the system
vent the system
electronic controller not working
call qualified personnel to have it replaced
diverter valve obturator seized
call qualified personnel to have it replaced
centralised system not working
contact person in charge of system
FAULT LED on + error
code 4 active
FAULT LED on + error
code 69 active
FAULT LED on + error
code 79/80 active
heating circuit pressure too low
safety thermostat cut-out
incorrect switch setting
restore system pressure
call qualified personnel to have it serviced
restore correct switch setting
DHW LED off
DHW storage thermostat disconnected
reconnect thermostat
DHW storage thermostat faulty
call qualified personnel to have it replaced
all LEDs are off
electric supply cut off
restore HIU electric supply
protection fuse burnt out
call qualified personnel to have it replaced
The water is hot
but does not
reach the
desired
temperature
DHW LED on
DHW temperature too low
increase set point
HIU strainer clogged
call qualified personnel to have it serviced
pump not working
call qualified personnel to have it replaced
excessive demand for DHW
decrease demand
electronic controller not working
call qualified personnel to have it replaced
centralised system temperature insufficient
contact person in charge of system
primary circuit flow rate insufficient
contact person in charge of system
Hot water
temperature is
too high
DHW LED on
domestic water cycle temperature set point too high
decrease set point
thermostat faulty
restore correct connection
modulating valve actuator faulty
call qualified personnel to have it replaced
valve obturator blocked in intermediate or open position
call qualified personnel to have it replaced
electronic controller not working
call qualified personnel to have it replaced
Hot water flow
rate is
insufficient
DHW LED on
possible clogged strainers
call qualified personnel to have it serviced
possible domestic water system shut-off valves
partially closed
open the valves
centralised domestic circuit cold water flow rate insufficient
call qualified personnel to have it serviced
Hot water flow rate
is zero
DHW LED off
possible domestic water system shut-off valves closed
open the valves
no cold water in centralised domestic circuit
call qualified personnel to have it serviced
The room does
not reach the
desired
temperature
CH LED on
heating cycle temperature set point too low
increase set point
chrono-thermostat temperature setting incorrect
check programming of chrono-thermostat
HIU strainer clogged
call qualified personnel to have it serviced
heating valve actuator faulty
call qualified personnel to have it replaced
heating valve obturator blocked
call qualified personnel to have it replaced
modulating valve actuator connector disconnected
reconnect actuator connector
presence of air in the system
vent the system
pump not working
call qualified personnel to have it replaced
pump cable not connected
restore connection
possible system shut-off valves/terminals closed
open the valves
centralised system temperature insufficient
contact person in charge of system
electronic controller not working
call qualified personnel to have it replaced
primary circuit flow rate insufficient
contact person in charge of system
centralised system not working
contact person in charge of system
CH LED off
chrono-thermostat time setting incorrect
check programming of chrono-thermostat
chrono-thermostat not working
check chrono-thermostat
all LEDs are off
Electric supply cut off
restore HIU electric supply
Protection fuse burnt out
call qualified personnel to have it replaced
FAULT LED on + error
code 4 active
heating circuit pressure too low
restore system pressure
FAULT LED on + error
code 5 active
heating temperature probe faulty
call qualified personnel to have it replaced
FAULT LED on + error
code 15 active
compensation temperature probe faulty
call qualified personnel to have it replaced
FAULT LED on + error
code 69 active
safety thermostat cut-out
call qualified personnel to have it serviced
FAULT LED on + error
code 79/80 active
incorrect switch setting
restore correct switch setting
Start-up of the
heat interface
unit heating
function causes
the safety circuit
breaker to trip
All LEDs are off
pump cable connector inserted the wrong way round
Check that the pump cable connector is inserted
the right way round
