Main Heating Main Heat 12, Installation & Service Manual, Page: 70 / 83

Fig. 59
15.11 Heat Exchanger
1. Drain the boiler (see section 15.1 paragraph 2 & 3).
2. Remove all components in the base of the airbox.
3. Undo the screws on the support bracket. Remove the screws securing the flow switch and return connections and remove the connections (
Fig. 57 ).
4. Remove the screws securing the heat exchanger manifold and remove the manifold ( Fig. 58 ).
5. Lift the heat exchanger assembly ( Fig. 59 ) and rotate the bottom upwards whilst pulling it forwards out of the airbox.
6. Fit the new heat exchanger and reassemble in reverse order.
7. Recommission the boiler and check the inhibitor concentration (see
Section 6.2 and 12.1 ).
page 50
15.12 Heat Exchanger Lower Insulation Pad (Fig. 60 )
1. Remove all components in the base of the airbox.
2. Remove the burner (see
section 15.10 ).
3. Remove the four bolts securing the combustion box base.
4. Remove the combustion box base.
5. Pull the central insulation panel down from the centre of the heat exchanger and remove the lower insulation pad.
6. Fit the new insulation pad and reassemble in reverse order.
15.13 Heat Exchanger Upper Insulation Pad ( Fig. 60 )
1. Remove all components in the base of the airbox.
2. Remove the burner (see
section 15.10 ).
3. Remove the heat exchanger (see section 15.11 ).
4. Remove the four bolts securing the combustion box base.
5. Remove the combustion box base.
6. Pull the central insulation panel down from the centre of the heat exchanger.
7. Fit the new insulation pad and reassemble in reverse order.