Main burner does not start either to draw
off D.H.W. or for heating.
– Check flowmeter; if necessary, replace it.
– The smoke stat has tripped; reset it (“25
BF” vers.).
– Check whether electric power is rea-
ching the gas valve actuator; check its
operation and, if necessary, replace it.
– Check operation of the smoke pressure
switch (“25 BF” vers.).
– The fan is operating but at low rpm, so
failing to activate the smoke pressure
switch (“25 BF” vers.); replace the fan.
– Replace the electronic card.
Boiler turns on, but after 10 seconds
“locks out”.
– Check that during electric wiring the
position of line and neutral have not been
inverted.
– The ignition/sensing electrode is faulty;
replace it.
– The control box is faulty; replace it.
Gas valve fails to modulate in D.H.W. and
C.H. modes.
– The sensor is interrupted; replace it.
– The modulator has a break in winding;
replace it.
– Check that the current to the modulator
complies with the specifications
– The control box is faulty; replace it.
Boiler is noisy or heat exchanger makes a
sizzling sound.
– Check whether circulation pump P is
obstructed; if necessary clear it out.
– Unclog impeller of circulation pump, clea-
ring away any impurities or sediments.
– Circulation pump is burnt out or has a
lower rpm than required; replace it.
– Check boiler output is adequate for
actual needs of heating system.
Boiler safety valve keeps tripping.
– Check charge cock is closed. If it doesn’t
close properly, replace it.
– Check system cold charge pressure is
not too high; keep to recommended
values.
– Check whether safety valve is out of cali-
bration; if necessary, replace it.
– Check whether the vessel is sufficiently
capacious to contain the water for the
system.
– Check preloading pressure of expansion
vessel.
– Replace expansion vessel if faulty.
Radiators fail to heat up in winter.
– The rotary switch is on “Summer”; swit-
ch to “Winter”.
– The room stat is set too low or needs
replacing because faulty.
– The electrical connections of the room
stat are wrong.
Main burner burns badly: flames too high,
deep yellow.
– Check that pressure of burner gas is
regular.
– Check burners are clean.
– Check coaxial assembly has been instal-
led correctly (“25 BF” vers.).
Smell of unburnt gases.
– Check boiler is properly clean.
– Check draught is sufficient.
– Check gas consumption is not too high.
Boiler operates but does not increase
temperature.
– Check gas consumption is not lower
than it should be.
– Check boiler is clean.
– Check boiler is sized in proportion to
system.
In the “25 BF” boilers, upon demand for
D.H.W. or heating, fan fails to turn at
max speed.
– Make sure that the smoke pressure
switch is working and that the relative
contact is in the rest position.
– Check whether connection tubes of
smoke pressure switch are obstructed
and, if necessary, clean away impurities
or condensate.
– The smoke pressure switch needs repla-
cing.
– Replace electronic board.
87
To Next Page
Loading...
