Instruction manual

Central Heating Mode

To be able to supply central heating, the selector switch

(19 Fig. 1) must be in ‘~~~~ 3 position. This will be

confirmed by the green indicator light 0 (22 Fig. 1).

When there is a demand for heating (either from the

room thermostat or the external programmer) and the

boiler temperature control is calling for heat.

The pump starts and at a flow rate of 4ltr/min the central

heating flow switch operates allowing the ignition

sequence to begin.

The first stage solenoid (12a Fig. 3) and safety solenoid

(12~ Fig. 3) open together to allow gas to the burner.

The ignition sequence begins and a continuous high

speed spark ignites the gas. As soon as a flame is

detected the orange indicator bulb 0 (23 Fig. 1) will

light. After 45 seconds the second stage solenoid (12b

Fig. 3) opens to allow the full gas rate.

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If a flame is not detected, after eight seconds, the

security solenoid closes and shuts off the gas. The red

lockout indicator bulb f (24 Fig. 1) will light. Press the

RESET button to attempt to relight.

The central heating flow temperature is controlled by

the central heating control thermistor (16 Fig. 3).

The boiler has been designed to minimise cycling and

will not attempt to relight for at least 3 minutes after the

boiler thermostat has been satisfied (this can be set to

30 seconds if required, see maintenance and service

guide).

When the room thermostat is satisfied the burner will

switch off and the pump will remain running for a further

3 minutes.

Fig. 3

Note:

It is possible to override the 3 minute delay by

pressing the RESET button (25 Fig. 1).

C&M

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