Appliance operation
2
1.5
Operation lights
Three lights (10 in Fig. 1.3) give detailed indication
regarding the operation of the boiler.
The following table gives the relationship between
each of the possible light combinations and their
meaning.
A short pulse every 4
seconds:
stand---by condition
Function selector in
position.
Anti---freeze system active
1 second pulse every 2
seconds: normally
operating boiler. Function
selector in
or
position
C.h. operation
D.h.w. operation *
Frost protect operation
D.h.w. operation
Excessive temperature on
primary circuit *
Faulty c.h. temperature
probe NTC
Faulty d.h.w temperature
probe NTC *
Faulty primary circuit
(no water or absence of
flow)
Lack of burner ignition (no
ignition signal from the full
seqence ignition device)
Ignition gas pressure
adjustment
Minimum gas pressure
adjustment
Lamp OFF
Lamp ON
Flashing lamp, alone or simultaneously
with an other lamp.
Flashing lamp, alternate with another
lamp.
* not on M90D.24SR and M90D.28SR boilers
US
E
