Domestic Hot Water Settings
RELAY 2 EXPLANATION
EXPLANATION:
N - Neutral
AUX_L - aux call for the boiler (Relay 1). If you supply this terminal with a 230Vac Switch Live, it will trigger Relay
1 (boiler relay). This terminal has the same function as 6a,b,c,d and 7a,b,c,d except 6/7 terminals are volt free
inputs. This input we use with 3-port valves for Y-plan systems, or in any other scenario where you need to
externally fire the boiler with a live input.
NC - Live NORMALLY CLOSED. When Relay 2 is not energized these 2 terminals have power. You can use these
terminals for Y-Plan wiring.
T_L - Live NORMALLY OPEN. When Relay 2 is disengaged this terminal is open and there is no voltage here.
When Relay 2 is engaged this terminal will become Live.
T_SL, SL, SL - become live outlets when there is a call for DHW and T_L and T_SL are bridged (and the high limit
thermostat is not satisfied, if present).
T_SL - L_T - Bridge with T_L directly or through a high limit thermostat. Bridged with T_L if unused.
SL - Live supply, usually to the orange wire on a motorised valve
SL can be connected to AUX_L if you need externally trigger Bolier Relay 1 (i.e. when wiring for Y plan heating).
N
T- L
Aux- L
NC
T-SL
SL
SL
NC
