Buderus Logamax plus GB142-24 Servicing Instructions page 58

7 Diagnosis
Locking boiler-fault code 3Y (flashing)
3 Y 2 1 5 The blower is running too fast.
Check the plug-and socket connection of the
tacho wire to the blower. This is the thin plug.
See page 88, fig 12.
Is the plug-and-socket
connection okay?
Check the tacho wire by measuring the
resistance (is the wire broken?).
See page 88.
Tacho wire okay?
Check that the mains voltage is
120V AC.
Sufficient mains voltage?
Check that there is no blockage in the blower
or the heat exchanger and that the flue-gas
system is connected.
Did you find a
blockage?
Check to see if there is a second blower in the
flue gas outlet conduit or air inlet system.
Is a second
blower fitted?
Check to see if the blower wheel has come
loose at the motor spindle.
Blower wheel loose?
Attempt to rectify the fault by temporarily
fitting another blower. See page 88.
Has the malfunction been repaired?
44
58 Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!
No
Yes
No
Yes
No
Yes
Yes
No
Yes
No
Yes
No
Yes
No
page 83
Locking boiler-fault code.
Restore the plug-and-socket connection.
Replace the tacho wire.
Have the electrical system tested.
Deal with blockage.
Take the second blower out of service.
Replace the blower.
See page 88, par. 8.1.6.
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