Flow Pipe
Fig. 52
Clip
NTC
Control Knobs
Discharge
Float Switch
Safety Thermostat
Fig. 53
PCB
Fig. 54
| Safety Float |
Alignment | Switch |
Bracket | Fig. 55 |
|
10.0Changing Components
10.9PCB (Fig. 54)
1.Pull off the two control knobs and disengage the securing tabs of the cover. Undo the screws securing the PCB.
2.Draw the PCB forwards and disconnect the wiring. Transfer the two potentiometer drive pins to the new PCB and replace in reverse order of dismantling.
3.Ensure that the wiring connectors are pushed fully on to the PCB terminals.
10.10NTC (Fig. 53)
1.Disconnect the 2 pin plug. Remove the clip retaining the NTC in the heat exchanger pocket. Pull the NTC out of the pocket.
2.Apply suitable heat transfer paste to the new NTC. Replace in reverse order of dismantling, using the clip previously removed. Ensure that the plug is fully engaged.
10.11Safety Thermostat (Fig. 52)
1.Disconnect the two leads from the thermostat.
2.Remove the screws securing the thermostat to the mounting plate on the flow pipe.
3.Replace in reverse order. The thermostat is not polarised - either wire can fit either terminal on the thermostat.
10.12Float Switches (Fig. 55)
1.Remove the fan as described in Section 10.5, paragraphs 1 to 5.
2.The two float switches are the same, but oriented differently. The discharge switch is at the left, the safety at the right.
3.To remove either switch disconnect the lead and pull off the alignment bracket.
4.Undo the retaining nut. The sealing grommet will be released from the sump body and allow the switch to be removed.
5.Note the orientation of the alignment rib on the switch. It is positioned uppermost on the safety float switch and to the bottom on the discharge switch.
6.Take the new switch assembly and insert it into the sump. Hand tighten the nut and slide the alignment bracket in place to ensure the switch is in position. Tighten the nut a further 2 turns.
7.Reconnect the lead to the switch, ensuring it is fully engaged.
32© Baxi Heating UK Ltd 2009
