Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Hinge down the PCB housing

Observation:

The jumpers are located at the bottom of the PCB housing
which is located on the right hand side of the appliance.
Ensure the jumpers are correct for this installation.
Blue Jumper - CN11 - Minimum Rate Ignition
If the blue jumper (CN11) is removed then the boiler will ignite at minimum fan speed. The fan speed will be reduced from 2800 rpm to 1900 rpm which will in turn reduce the ignition gas rate. Removing this jumper may help appliances with hard ignition.
Red Jumper CN12 - Change in CH rate
If the red jumper (CN12) is removed then the maximum fan speed is changed to allow 30kW output. Removing this jumper on appliances with an output of less than 30kW will have no effect on the appliance operation.
Blue & Red Jumpers - Thermal Store
If both the blue and red jumpers are removed then appliance will assume a thermal store is connected. The heating rate is maximum and the ignition rate is normal (not minimum). The set-point is set at 78°C and is not adjustable. The boiler will not run at low rate however long it is running for.