PENSOTTI PCI 18, Instruction Manual

Page: 56 / 70

MAINTENANCE INSTRUCTIONS
52
6.7 Maintenance operations
Before carrying out any cleaning or part replacement
operations, ALWAYS turn off the ELECTRICITY,
WATER and GAS supplies to the combination water
heater.
Pensotti LLC will not be held responsible for damage to
any of the wate
r heater’s components caused by non-
compliance with this instruction.
For all maintenance operations requiring removal of the
water heater casing, refer to the procedures described in
paragraph
6.4 “Accessing the water heater”.
Cleaning the main exchanger module and combustion unit (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 gasket on the cover of the burner.
Clean the heat exchanger 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.
primary
heat
exchanger
flue
connection
chamber
stainless
steel
pipe
coil
ceramic fibre
washer
Fig.
2
B
A
Fig.
1
premix burner unit
burner
ionisation
electrode
ignition
electrode
primary heat
exchanger