Advanced Boiler Control ('Abc®'-Control); Regulating The Water Temperature; Low Flow / Water Protection; High Limit Temperature Protection - REMEHA Avanta 12v Installation & Service Manual

8.3.2 Advanced boiler control ('abc®'-control)
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 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 is fitted with an electronic temperature
regulator with flow and return temperature sensors. The flow
temperature can be set to between 20 and 75°C, see 2.10.8
(factory setting 75°C). The boiler modulates it's output up and
down to match the flow set point from internal or external con-
trol. 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).
8.3.4

Low flow / water protection

The Remeha Avanta has a low-water protection based on
temperature readings. By modulating down as soon as there
is a risk of an insufficient water flow, the boiler will keep work-
ing for as long as possible. An insufficient water flow, however
caused, - indicated by a flow/return dt ] 22°C or a rate of
rise in the flow temperature > 1°C/sec – will be sensed by
the 'abc control which will shut the boiler down in a blocking
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mode with the display showing (code 9) for 10 minutes and
before re starting.
If there is no water in the boiler or if the pump is not running, it
will go to lock out (code é7) and require manual re-set.
8.3.5

High Limit temperature protection

If the flow temperature exceeds 98°C the high limit tempera-
ture protection device switches off the boiler in a lock out
mode with the display showing (code é1). This mode will
require a manual re-set.
When the fault is corrected, the boiler can be restarted by
pressing the reset-key on the control panel and holding for 3
seconds.
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Remeha Avanta
') continuously
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