Wiring 230V thermostat contacts
In a minority of cases, the thermostat connection to the boiler may require a
230V rather than a low voltage connection. This should be specified in your
boiler manual. Note that damage may occur to the boiler if mains voltage is
incorrectly introduced to a low voltage circuit, so take great care. 230V can be
introduced to the circuit by jumping from the live terminal as shown below.
Room thermostat
terminals requiring
230V
Live mains jumped
from the second ‘L’
terminal across to
the ‘common’
terminal .
Install 1: combi boiler