Regulating; Advanced Boiler Control ('Abc ® '-Control); Regulating The Water Temperature - REMEHA Avanta 24c Installation And Service Manual

8. Technical specifications and working principle
64
stops the motorised valve automatically returns to the DHW
position. This three-way valve is electrically controlled by the
'abc
' control and only consumes power when it is changing to
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a different position.
The plate heat exchanger is protected from debris by two fil-
ters one in the cold water supply and one in the primary flow
to the diverting valve – Note: the primary flow filter self cleans
when the flow reverts back to heating mode.
System boiler operation
The Remeha Avanta Plus 18s, 24s and 30s have the same
design and layout as the combi range without the DHW com-
ponents (three way valve and plate heat exchanger).
8.3.1

Regulating

The Remeha Avanta Plus is a fully modulating boiler and can
be regulated using one or more of the following methods;
1. O pen Therm – 2 wire interface compatible with the Remeha
qSense room compensator and the Remeha iSense outside
weather compensator or with any other proprietor's Open-
Therm controls.
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2. O pen Therm thermostat in combination with an external
time clock.
3. On/Off room thermostat – volt free (on the X9 terminal
block).
4. O n/Off room thermostat – 230 V (on the X2 terminal block).
5. 2 30 V Switching time clock - compatible with the Remeha
two channel time clock or with any other proprietor's time
clock. For further details see par. 2.8.
8.3.2 Advanced boiler control ('abc
An intelligent advanced boiler control ('abc
monitors the boiler conditions and ensures a very reliable
supply of heat. This control system is adept at dealing with
negative influences from the system such as flow reduction,
airflow problems and alike. In the event of such influences, the
boiler will not go to "lock-out" failure mode, but will in the first
instance modulate back, and if necessary, depending on the
nature of the circumstances, will temporarily switch off (shut-
down or control stop), and then after a short while simply try
again.
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Provided that the situation is not actually hazardous, the
Remeha Avanta Plus will always try to supply heat.
The 'abc '- control prevents unnecessary additional call outs.
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8.3.3

Regulating the water temperature

The Remeha Avanta Plus is fitted with an electronic tempera-
ture regulator with flow and return temperature sensors. The
flow temperature can be set to between 20 and 85°C, see
2.9.8 (factory setting 75°C) The boiler modulates it's output up
and down to match the flow set point from internal or external
control. When the boiler is at it's at minimum output and the
flow temperature still continues to rise, once the flow set point
is exceeded by 5°C the boiler will shut down on a controlled
stop (code 8).
Remeha Avanta Plus
'-control)
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') continuously
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