Trianco TRISTAR OPTIMA JUNIOR K CB, Installation Instructions Manual, Page: 18 / 44

18
Combi (CB) Model
The boiler should be connected to a double-channel
programmer with volts-free switching to allow the
control of the central heating and hot water. A room
thermostat should also be fitted.
Alternatively, a digistat can be fitted in place of these,
controlling the central heating and leaving the hot
water facility on permanently. See
fig 21 for digistat
wiring.
In both circumstances, it may also be necessary to fit
a frost thermostat, should there be a possibility of the
water in the pipes freezing.
When using standard controls, the boiler flow
temperature can be set using the heating knob on the
control panel. The hot water control becomes inactive
when the temperature is set via the cylinder
thermostat.
System (SB) Model
The boiler should be connected to a double-channel
programmer with volts-free switching to give the
option of controlling both the central heating and hot
water separately. A room thermostat and cylinder
thermostat should also be fitted.
It may also be necessary to fit a frost thermostat,
should there be a possibility of the water in the pipes
freezing.
The System (SB) model can be wired to both Y-plan
and S-plan control systems (see
figs 22 & 23 ).
When using standard controls, the boiler flow
temperature can be set using the heating knob on the
control panel. The hot water control becomes inactive
when the temperature is set via the cylinder
thermostat.
5.3 CONTROLS & WIRING
FIG. 21
IMPORTANT:
All external controls must be volts-free switching type.