10
Troubleshooting
Logano plus GB312 – 6 720 806 273 (2013/01)
52
10.2
Operating and fault indications
10.2.1 Status indicator
Type
1)
Display code Event code Cause
Description
Test procedure/cause
Measure
2P
564
Temperature rises too
quickly at the boiler
temperature sensor
( >126°F/min; >70°K/
min).
Heat exchanger cut-out due to
excessive rate of temperature
rise.
Little or no heat draw (e.g.
thermostatic valves and
mixer closed).
Boiler loop flow rate too
low.
Pump does not work.
Pump installed opposite to
intended direction of flow.
Deposits in water carrying
parts of boiler (dirt from
heating system, limescale).
Ensure adequate heat
transfer.
Install adequately
dimensioned pumps.
Check whether the pump
is being activated. Replace
pump if necessary.
Install pump in the correct
orientation.
Flush/clean water side of
boiler heat exchanger with
agents suitable and
approved for aluminum
BC
OA
-
Appliance is in
optimized switching
mode.
A new burner demand occurs
within the set switching
optimization time. Appliance
is in anti-cycle phase. The
standard switching
optimization time is 10 min.
Check output setting on
BC10 basic control unit.
Check control setting on
RC35 controller.
Adjust boiler output to
required heat demand for
building.
Adjust control setting to
system conditions.
BC
OH
-
The appliance is in
standby mode; no
heat demand present.
The boiler is on standby and
there is no call for heat from
the heating zone.
-
-
BC
OY
-
The current boiler
temperature is higher
than the set boiler
water temperature.
The current boiler
temperature is higher than the
set boiler water temperature.
The boiler shuts down.
-
-
BC
OP
-
Waiting for fan to start
up.
Start-up of the fan has to be
detected before the sequence
can be continued.
-
-
BC
OE
-
The appliance is in
standby mode, heat
demand is present
but too much heat is
being delivered.
The current heat demand from
the heating system is lower
than that supplied by the
minimum burner modulation
setting.
-
-
BC
OU
-
Beginning of burner
start-up sequence.
-
-
-
BC
OC
-
Beginning of burner
start-up.
-
-
-
BC
OL
-
Gas valve opening.
-
-
-
BC
OF
-
Lack of flow through
boiler.
Temperature difference
between supply and return
> 27 °F, > 15 K.
Temperature differential
between boiler supply and
high limit temp. sensor
> 27 °F, 15 K.
Check supply temp. with
BC10,
Check return temp. with
RC35 or service keys,
Check resistance of high
limit temp. sensor.
Adjust the heating pump
setting.
Use a temperature
measuring instrument to
check the surface
temperature of cast
section in which the high
limit temp. sensor is
mounted.
Check if cast section is
blocked with dirt.
Table 22 Operating codes1) V = interlocking; B = inhibiting; BC = operating code
