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Enamel lined storage vessels are protected against corrosion by sacrificial anodes. The rate at which the anodes
are depleted is dependent on the quality of the water, therefore it is important that the anodes are inspected as
follows:
1.
Drain the water system. Refer to Section 14.3: DRAINING WATER SYSTEM.
2.
Remove the plastic covers to expose the anode retaining plugs.
3.
Remove the anodes and check their condition.
NOTE: If the anodes have reduced in size by more than 40% at any point along their length or if they are
severely pitted, new anodes should be fitted. Where the anodes are covered with particles they
should be cleaned. For reference, when new, the anode has a diameter of 21mm.
4.
Reassembly procedure is the reverse of removal, ensuring all water joints are sealed using an
appropriate jointing compound.
NOTE: Where a water softener is used, the conditioned water may reduce the serviceable life of the tank.
The condition of the anodes must therefore be checked more frequently.
14.5
CLEANING THE HEAT EXCHANGER
1.
Remove the gas valve cover panel by lifting it from its resting place and tip forward. This gains access
to gas valve(s) and the upper gas train.
2.
Remove the self-tapping screws from the bottom grille panel and pull forward, taking care not to snag
the pilot tube, and remove.
3.
Remove the self-tapping screws from the front draught diverter baffle and pull forward to remove.
4.
Using a Pozi-Drive screwdriver, remove the wiring harness from the gas valve(s). Undo the pilot tube
from the gas valve using a 11mm spanner and move aside.
5.
Using an 8mm socket, remove the gas train.
6.
Remove the self-tapping screws from the upper front panel, pull forward and down slightly to detach the
panel. This now gains access to the rear of the control box (thermostat and internal wiring).
7.
Cut through the cable ties securing the ionisation and spark cables (coloured white and orange
respectively) taking care not to damage the insulation of any secured wires. Disconnect the ionisation
and spark cables from ignition module pins 13 and 16 and pull cables through to the pilot assembly,
taking care not to strip any insulation on bare metal parts.
8.
Remove the self-tapping screws from the insulation panel (with slight glass aperture) and remove the
panel. Remove the remaining self-tapping screws from the unpainted louvered fascia panel and pull
forward to access the burners and heat exchanger underside. (Note: This panel is backed with fibre
board; care must be taken to avoid damage.)
9.
Having now gained access to the burner rack, lift and pull out the burner bars and clean each bar using
a suitable brush ensuring that the burner ports are clear of any obstructions and that there are no major
cracks in the outer wall. Should any burner bar be in sub-standard condition, a replacement should be
fitted.
10.
Using a Pozi-Drive screwdriver undo retaining screws from the rear of the pilot assembly bracket and
carefully with draw the complete pilot assembly forward and from underneath the burner rack.
11.
With the pilot assembly removed, check that there are no signs of damage to the spark or ionisation
probes and cables. If any damage is evident, the complete pilot assembly must be replaced. Check that
the pilot injector is free from debris.
12.
To access heat exchanger baffles, the front inner draught diverter fascia must be removed. Undo the
self-tapping screws on the lower left and right sides of the flue hood and pull out the front under-fascia.
13.
Unclip the v-baffles and remove each from the heater. Clean using a suitable brush replacing any
baffles that are in a poor condition.
14.
Check the condition of the fibre board lining of the combustion chamber replacing any significant
damaged sections.
15.
Using a suitable brush, clean all traces of soot and debris from the heat exchanger, taking care not to
damage the copper fins.
