MAINTENANCE INSTRUCTIONS
38
Cleaning the main exchanger module and
combustion unit
(see fig. 1)
•
Disconnect the electrical connections of the
electric fan.
•
Disconnect the joint and remove the pipe linking
the gas valve to the injector unit (venturi).
•
Disconnect the joint and remove the gas feed
pipe from the gas valve.
•
Un-plug the ignition electrode and flame
detection wires from the ignition control unit.
•
Unscrew the ring-nut at the bottom of the room-
sealed chamber and remove the gas valve.
•
Unscrew the nuts securing the burner unit
(consisting of a fan, manifold and burner) to the
primary heat exchanger.
•
Remove the burner unit, paying particular
attention not to remove the ceramic fibre
protection from the bottom of the heat
exchanger.
•
Check that the burner is not affected by deposits,
scaling or excessive oxidation. Check that all the
holes in the burner are free;
•
Clean the electrodes carefully without altering
their positions with respect to the burner;
•
Clean the burner cylinder using a non-metal
brush and without damaging the ceramic fibre;
•
Check the integrity of the washer on the cover of
the burner;
•
Clean the heat exchanger (see fig. 2) using a
household
detergent
for
stainless
steel,
distributing the product on the spirals of the
exchanger using a brush. Do not wet the ceramic
fibre coating. Wait a few minutes then remove
the deposits using a non-metal brush. Then
remove the residues under running water;
•
Remove the pipe clip, remove the condensate
drainpipe and clean under running water.
•
Unscrew the joint to the condensate trap, remove
the trap and wash under running water.
•
With the cleaning completed, re-assemble the
components following the above procedure in
reverse order.
•
Finally, check the boiler to make sure that all gas
and exhaust joints are tight.
Fig. 1
premix burner unit
burner
ionisation
electrode
ignition
electrode
primary heat
exchanger
B
A
primary heat
exchanger
flue connection
chamber
stainless steel
pipe coil
ceramic fibre
washer
Fig. 2
