Main Heating Main Heat 12 Installation & Service Manual page 50

3. The Main 30 Heat is factory set to give a maximum output of 22.0 kW. The Control PCB jumper positions are as follows:
CN11 (Blue) CN12 (Red)
If the installation requires a greater output to achieve the desired room temperature, this can be increased to 30.18 kW and the boiler can be adjusted as
follows (Fig. 32):
a) Remove the top right hand securing screw and hinge down the PCB housing.
b) Remove the Red jumper labelled CN12 from the bottom left hand side of the PCB.
c) Hinge back up the PCB housing and secure with screw.
4. Route the incoming electrical cable/s through the grommet in the support bracket. This will prevent damage to the cable.
5. Lay the cable through the cable clamp to gauge the length of cable required when it is connected to the 4-way terminal block.
6. Connect the (S/L), (N) and
7. Check the electrical installation for; earth continuity, short circuits, resistance to earth, correct polarity and fuse failure.
wires to the 4-way terminal block (Fig. 33) and refit the cable clamp (Fig. 31).