7
Heating circuit pressure switch fault
Error code 4
The SATK40 series HIU continuously monitors the status of the
pressure switch controlling the water pressure in the closed-circuit
user heating system.
If the pressure switch trips, the heating circulation pump
immediately comes to a stop and the modulating valve is
completely closed.
N.B.: A low expansion vessel pre-charge value can cause a
pressure switch fault (see page 4 - “Filling the user system”).
Safety thermostat cut-out
(in LOW temperature setting)
Error code 69
The HIUs configured to support low temperature heating
continuously monitor the safety thermostat controlling the flow
temperature.
If the safety thermostat is activated during a general cycle, the
heating circulation pump immediately comes to a stop and the
modulating valve is completely closed.
Removing a fault
To restore the operating mode press the manual
RESET button.
Safety and alarms
Error codes associated with faults signalled by illumination of the
FAULT LED are also shown on the display.
69
6
Removing a fault
Return to the operating mode is possible once the temperature
probe is operating correctly (see page 10 - “Temperature probe
replacement”).
4
Probe fault
If a temperature probe fails, the associated cycle will be stopped
immediately and disabled.
Any requests to run cycles not associated to the previous one will
continue to run normally.
Heating probe fault
Error code: 5
5
Compensation probe fault
Error code: 15
Removing a fault
Restore the correct switch setting as shown on page 8.
79
Incorrect DIP-switch setting
Error code 79
Removing a fault
The heat interface unit is disabled due to incorrect setting of the
dip-switches. Restore the correct setting as shown on page 8.
Incorrect DIP switch setting (heat interface unit disabled)
Error code 80
80
