Central Heating Overheat Thermostat; Dom. H/Water Limit & Frost Thermostat; Sensor And Ignition Electrode; Sensor And Ignition Leads - Potterton Combi 80 Installation & Service Instructions Manual

Replacement of Parts - Page 27
5.1

Central Heating Overheat Thermostat

Fig. 17
1. Remove the white front case and three air box covers.
See 4.1 & 4.3 in 'Routine Maintenance'.
2. The thermostat is located on the outlet tail on the right
hand side of the heat exchanger. Disconnect the two
electrical leads.
3. Undo the two long fixing nuts and remove the thermostat
from the heat exchanger.
4. Fit the new overheat thermostat taking care not to touch
the exposed disc on the thermostat face. Do Not use
heat sink compound. Re-assemble in reverse order.
5.2 Domestic Hot Water Limit & Frost
Thermostats
1. Remove the white front case and base panel.
See 4.1 & 4.2 in 'Routine Maintenance'.
Lower the control panel, (one screw).
2. Disconnect the electrical leads from the thermostat.
3. Remove the two securing screws and pull the
thermostat clear of the pipe.
4. Fit the new thermostat and re-assemble in reverse
order.
5.3

Sensor and Ignition Electrode

1. Remove the white front case, base panel, air box covers
and combustion chamber front panel. See 4.1 to 4.3 &
4.6 in 'Routine Maintenance'.
2. Disconnect the lead from the base of the electrode to be
changed.
Remove the electrode retaining screw and remove the
electrode from the burner.
3. Fit new electrode and re-assemble in reverse order,
checking the gap measures 4mm ± 0.5mm (Fig. 14).
5.4

Sensor and Ignition Leads

1. Remove the white front case, base panel and main air
box cover. See 4.1 to 4.3 in 'Routine Maintenance'.
2. Lower control panel (one screw)
3. Note run of lead.
Remove lead ends from electrode and Full Sequence
Control Board. Pass lead through the silicone grommet.
4. Fit new lead in correct position.
5. Re-assemble in reverse order. Ensure the silicone
grommet is correctly fitted and not damaged. Replace if
necessary.
5.5

Burner

- Fig. 15
1. Remove the white front case, air box covers,
combustion chamber, front panel and burner assembly.
See 4.1, 4.3, 4.6 & 4.8 in 'Routine Maintenance'.
2. Remove the electrodes from the main burner and re-
assemble onto the new main burner, check electrode
gap is 4mm ± 0.5 Fig. 14).
3. Re-assemble in reverse order.
5.6

Injectors

- Fig. 15
1. Remove the white front case and main air box cover.
See 4.1 and 4.3 in 'Routine Maintenance'.
2. Replace the relevant injector/s.
3. Re-assemble in reverse order.