User manual

Page 35
When there is no water present in the boiler or the water pressure is too low/high, the boiler will go into lock-out
and will show a corresponding message in the display.
By pressing the [SERVICE] button of the boiler, the boiler can be started without a heating demand. The boiler
will start to fire and also the pump will start to run. Firing of the boiler without a water flow (but filled with water!)
will cause “boiling noises”. Check during this “service function” operation also the flow and return temperatures
of the boiler by pressing the [◄] button once. The temperature difference of the flow and return must be at least
13ºC and maximum 25ºC. This temperature difference indicates that there is a (enough) water flow over the boil-
er; this water flow prevents the heat exchanger of possible damage caused by a thermal overload.
Another safety feature of the boiler, to make sure that there is enough water flow over the boiler, is the monitor-
ing of the flow and return temperatures (T1 and T2). When the temperature difference (delta T) between the flow
and return exceeds a certain (set) value, the following warning messages will be shown in the display.
When this T2-T1 value exceeds the lock-out setting, the boiler will switch off and the following lock out code will
be shown at the display.
When these messages appear and/or the boiler will lock out, it means that there is not enough flow over the boil-
er. In this case check the functioning of the pump.
The boiler has no built in water-flow switch. If there is the possible risk of a water-flow blockage of the (external)
heating system, the following pre-cautions can be taken to ensure a water flow over the boiler:
 Separate the boiler circuit from the (external) heating circuit by using a low loss header or plate heat ex-
changer.
When the boiler is not equipped with an internal (built in) water pressure switch, install a water pressure switch
externally, in series with the room thermostat.
During and after the commissioning of the boiler, the operation of the boiler pump must be checked, before leav-
ing the installation/Boiler room.
REMINDER: Always check the pump is running before firing the boiler!
Display message T 2 - T 1 h i g h
9 9 9 , 5 h r s
Reason The maximum delta temperature T2-T1 has exceeded the blocking temperature,
w hich is set in the parameters.
Display message H e a t e x c h a n g a t r i s k
9 9 9 , 5 h r s
Reason The max delta temperature T1-T2 has exceeded the blocking temperature more
than three times. Set in the parameters P2 CQ-P2 CV (∆T>P2 CV (binnen t=P2 CQ).
Display message F l o w R e t u r n d t f a u l t
F16 p u m p o n 9 9 9 , 5 h r s
Reason The max delta temperature T1-T2 has exceeded the blocking temperature.
Programmed at the parameters P2 CO, P2 CR untill P2CV.