7.4 Set the Primary Pump to Speed 3.

7.5 Set the Heat Bank Thermal Store Pump to speed 2.

7.6 Follow any specific commissioning instructions given in the Boiler Installation Instructions. IMPORTANT: ONLY SUITABLY QUALIFIED INSTALLERS CAN COMMISSION A GAS BOILER.

7.7 Turn on the electrical supply.

7.8 Bleed all pumps as described.

7.9 Run through the operation of the system as follows:

7.9.1 Set the programmer to Hot Water ON.

7.9.2 The boiler should fire, and the primary pump turn on. Within a short time (3 minutes) the flow from the boiler should feel hot to the touch. Check that the pipework to the primary coil is also hot. The flow to the central heating should not be hot at this stage.

7.9.3 Set the Programmer to Heating ON. The flow to the heating circuit should now get hot.

7.9.4 Turn off both the Hot Water and Heating on the Programmer. The Boiler should stop firing, and the primary pump stop - on systems where the boiler uses a pump over-run, the pump may not turn off for a few minutes.

7.9.5 Bleed the entire system to remove air.

7.9.6 Turn the Hot Water ON to allow the cylinder to fully recover. As it does, adjust the Balancing Valve on the Flow (or return) to the Primary Coil to obtain a temperature difference of approximately 10°C (or as specified in the Boiler Installation Instructions) between the Boiler Flow & Return.

7.9.7 Once the cylinder has recovered, check that hot water is available at all outlets.

7.10 Set the Room Thermostat as required.

7.11 Should the incoming mains flow rate exceed the maximum transfer rate for the domestic heat exchanger, the hot outlet temperature will drop. This can be corrected by adjustment of the stop cock on the incoming mains to achieve a flow rate off approximately 26 litres/minute.

7.12 Check that a copy of both the Installation / Users Instructions is left with the Heat Bank Thermal Store, or occupier, as required.