Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 39

Connecting the secondary circuit
Aligning the indoor unit
Fig. 30
Temperature limiter
With underfloor heating circuits, install a temperature
limiter to restrict the maximum temperature in the flow
of underfloor heating systems.
This temperature limiter is triggered as soon as the
flow temperature exceeds the set value.
(cont.)
1.
SW17
2.
Once the temperature limiter has been triggered, the
room heating ceases in the particular heating/cooling
circuit.
Installation sequence
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