4.3 Flow from Boiler.

4.4 Return to Boiler

4.5 Flow to Heating Circuit

4.6 Overflow, 22mm Copper  IMPORTANT:  PLASTIC PIPE SHOULD NOT BE USED.

4.7 Primary Pressure Relief, should be fitted to provide a visible warning of discharge.

5 WIRING

5.1 All cable should be Heat Resistant, and suitable for 230V 50Hz supply.