17
Externa 30 O
Cod. 3540T540 - 04/2009 (Rev. 00)
3.4 Troubleshooting
Troubleshooting
Flow Diagram 1
Checking Power Supply-System Pressure and Anti-freeze Protection
Is LED5 on?
Put main switch to on
CH Selector to
Summer position
Is 240V present across
terminals X1-1 X1-2?
Check and if necessary
replace 2A fuse
YES
Is LED5 ON now?
Repair external
wiring fault
NO
NO
Replace
main board
NO
YES
Is LED5 flashing?
YES
Water pressure
is not set
between
1 - 1,5 bar?
YES
Set pressure to
1 - 1,5 bar
Check water
pressure
switch wiring
connection
NO
Does fan run at full speed?
NO
Go to CHART 2
NO
YES
Does CH Pump run?
If the boiler temperature
is less than 5°C
frost protection is activated
Disconnect
CH flowtemp sensor
Has fan speed stopped?
Check and if necessary
replace main board
NO
YES
Check and if
necessary
replace water
pressure switch
Chek the following carefully before starting
Gas supply is turned on, is adequate and purged
Electricity supply is turned on
Polarity is correct
CH pressure is set between 1 - 1,5 bar
CH pump spins freely
YES
NO
Is Relay RY101 switch on?
Check and if
necessary
replace pump
YES
NO
Check pump
wiring
connection
YES
Go to CHART 2
