Viessmann VITOTRONIC 100 GC1B Installation And Service Instructions Manual page 95

Function Description
Vitotronic 100, GC1B Installation and Service
Boiler Water Temperature Control
(continued)
Switching Hysteresis, Burner
Permanent Switching Hysteresis
Code "04:0"
Heat Demand-dependent Switching Hysteresis
The heat demand-dependent switching hysteresis takes
the boiler load into account.
The switching hysteresis, i.e. the burner runtime varies
subject to actual heat demand.
ERB50 Function
Code "04:1"
Subject to heat demand, values between 6 and 12 K result.
ERB80 Function
Code "04:2"
Subject to heat demand, values between 6 and 20 K result.
Control Sequence
Boiler Goes Cold
(set value −2 K)
The burner start signal is set as the set boiler water
temperature minus 2 K, and the burner starts its own
monitoring program.
The burner start may be delayed by a few minutes subject
to the number of auxiliary circuits and the combustion type.
Boiler Heats Up
The burner stopping point is determined by the shutdown
differential (coding address "13" in category 2 "Boiler").
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