IDEAL LOGIC HIU Direct HT, Installation And Servicing

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13 LOGIC HIU -
Installation & Servicing / Users
22 OPTIONAL LOW CH Temperature
operation ONLY.
Where the low temperature (Underfloor heating) mode is active.
Central heating low temperature sensor fault
If the safety compensation temperature sensor fails the
heating will cease immediately.
Rectify this fault – Replace the fault sensor ensuring good
contact, apply a CH heat demand. If the fault does not
automatically reset, activate the reset button on the control
box. The system should now function as normal.
Safety thermostat lockout – Error 69
The HIU is configured to support low temperature heating
(low temperature models only), which constantly monitors the
heating flow temperature and includes a safety thermostat. If
the thermostat is activated during a general cycle, the circulation
pump will immediately stop, the mixing valve and safety lock valve
(SATK20103) will close. Safety thermostat activation is indicated by
a steady, red fault LED on the electronic controller. This fault locks
all functions as found in a power failure. The thermal safety valve
prevents hot water for heating purposes from entering the system.
After the user has reset the isolation imposed by the safety
thermostat, the shut-off valve can only be re-
enabled when the mixing/modulating valves
are completely closed again. This means that
if a domestic water cycle is in progress, the
activation of the shut-off valve will be postponed
until the end of that domestic water cycle.
Once the fault has been removed. The reset button on the
main control will have to be pressed.
The unit should now be operational.
INDIRECT OPERATION
22 CONTINUED
Safety valve fault - Error code: 76 LOW temperature
Should the operating temperature drop below the required 25°C
as a result of a faulty safety valve; the flashing fault LED on the
electronic controller will appear and Error code 76 will be displayed.
Rectify this faults – rectify the faulty safety valve, if the fault
does not automatically reset. Activate the reset button on the
control box. The system should now function as normal.
Safety setting incorrect - Error code: 76
Removing a fault - Restore correct dip switch setting
according to Table 1, if the fault does not automatically reset.
Activate the reset button on the control box. The system
should now function as normal.
Safety setting incorrect - Error code: 79
Removing a fault - Restore correct switch setting according
to Table 1.
Automatic controller function
Reset mixing/modulating valve to zero
Immediately after the power supply has been switched on, the
position of the mixing/modulating valves is reset to zero.
Pump anti-clog - When the pump is not in use, it is powered
on for a period of 5 seconds every 24 hours.
Mixing valve/modulating valve anti-clog - The anti-clogging
cycle for the mixing/modulating valve is run every 24 hours.
Domestic water generation:
DHW preheating function (MT & HT)
The domestic water preheating function is signaled by the
flashing yellow DHW LED. The function is enabled by setting
dip switch 5 to the ON position.
During periods when the domestic water cycle is not used, if the
DHW probe detects a temperature 10°C below the SET value, the
controller partially opens the domestic water modulating valve for
the time required (max. 5 mins) to bring the temperature detected
up to a value 5°C below the set point value.
The domestic water preheating function is signalled by the
flashing yellow DHW LED. This function is less of a priority
than any domestic water or heating cycles.
5
ON