112
Display message
F7
F l u e
t e m p
t o o
h i g h
p u m p
o n
9 9 9 , 5
h r s
Reason
Flue gas temperature exceeded three times the limitation value
within a certain period.
Cause:
Heat exchanger polluted and not able to transfer enough heat to system water.
Corrective action:
Check and clean heat exchanger.
Cause:
Bad flue gas sensor or sensor connection (partly shorted).
Corrective action:
The sensor is of the type NTC. This means if the temperature rises the resistance lowers.
A partly shorted sensor will drop its resistance and therefore 'measure' a raise in temper-
ature when actually there is none.
Check for moist in the sensor connections or replace sensor.
Cause:
There is no water in the unit while firing.
Corrective action:
This is an unlikely situation while all the safeties for checking the water presence didn't
detect anything. Only a lot of air in the system/unit (under pressure) can cause the water
pressure switch to switch while no water is present. Also the water leak detection
did not react. Bleed all air from the unit so the heat from combustion can be transferred to
the water and won't leave through the flue system.
Cause:
Heat exchanger failure.
Corrective action:
This is an unlikely situation but when there is severe damage to the heat exchanger, the
combustion product will not be able to transfer all heat to the system water. The heat that
is not transferred will convert to an increased flue gas temperature.
Display message
F5
N o n
R e t u r n
V a l v e
p u m p
o n
9 9 9 , 5
h r s
Reason
NR valve contact (signal) lost for fixed amount of time.
(If
P2MT = 2 or 3
)
Cause:
It is not proven that the non-return of the burner that is not burning is closed.
Corrective action:
Check the state of the Non-Return Valve:
> Is the valve moving freely to the open and closed position.
> Is there debris/fouling or corrosion in the valve to prevent the valve to move freely.
Check for loose wiring/connections in the circuit to the proximity switch of the NRV
Check the parameter settings of the burner controller
Cause:
It is not proven that the non-return valve of the unit is closed.
Corrective action:
Check and repair or replace NRV
Display message
F13
P a r a m / H a r d w
f a u l t
p u m p
o n
9 9 9 , 5
h r s
Reason
Failure during programming of the parameters.
Cause:
Programming of the parameters NOT successfully completed.
Corrective action:
Unit is not in stand-by mode (fan must not run during programming).
Check programming wire and connections and try again.
Check if the software complies with the PCB.
Replace the programming wire.
Replace the display PCB.
