Technical data

13.0 Changing Components

13.6 Flue Sensor (Fig. 49)

1. For ease of access on 12 - 28 models remove the

Expansion Vessel as described in Section 13.17.

2. Ease the retaining tab on the sensor away and disconnect

the electrical plug.

3. Turn the sensor 90° anticlockwise to remove - it is a

bayonet connection.

4. Reassemble in reverse order.

13.7 Heating Flow & Return Sensors (Fig. 50)

1. There is one sensor on the flow (red wires) and one

sensor on the return (blue wires). Note: For access to the

return sensor on 12 - 28 models first remove the fan and

air/gas collector (see 13.2).

2. After noting the position prise the sensor clip off the pipe

and disconnect the plug.

3. Connect the plug to the new sensor and ease the clip onto

the pipe as close to the heat exchanger as possible.

13.8 Safety Thermostat (Fig. 51)

1. Pull the plug off the safety thermostat.

2. Remove the screws securing the thermostat to the

mounting plate on the flow pipe.

3. Reassemble in reverse order, ensuring that the plug is

pushed fully on.

13.9 Hydraulic Pressure Sensor (Fig. 52)

1. Close the flow and return isolation taps and drain the

primary circuit. Remove the fan and heat exchanger flow pipe.

2. Remove the plug from the sensor and pull the retaining clip

forwards. The clip is captive and does not need to be fully

removed.

3. Reassemble in reverse order.

Flue Sensor

Electrical

Plug

Fig. 49

Heating Flow Sensor

Fig. 50

Control Box removed

for clarity

Fig. 51

Safety Thermostat

Securing Clip

(captive)

Fig. 52

Hydraulic Pressure

Sensor

Plug