Ariston ACO 27 MFFI

[Mikegriffin99]

I have got a problem with an Ariston ACO 27 MFFI Combi, it won't stay lit, and shows a fault code of SO1 then SO2, then AO1. This I understand means ignition failure, but the book is no help after that apart from telling ou o check that the gas supply is present, which it is. I realise it could be flame sensing, but the electrodes appear Lund, the spark generator is working,the burner lights and goes out after about ten second. Can anyone help, stuck at clients house trying to get then some hot water today!!!

 

[Mikegriffin99]

@mikegriffin99 or [email protected]

 

[jtsplumbing]

May be flame detection electrode or PCB .

 

[Mikegriffin99]

Hi, trying not to diagnose as pcb, cleaned and re-aligned sensor probe, have to try to find a way of checking pcb, anybody have a definitive test for flame sensing on pcb? I'll have to try new probe first!!!
thanks for trying to help.

 

[Mikegriffin99]

Have been trying on #legendsofgas but no result yet !!!

 

[topdog]

Shutdown Due to Ignition Failure
This anomaly is indicated by “A01” on the display. To reset the
boiler, press and then release the reset button .
At this point, the electronic ignition system will attempt to light the
burner again.
Should the boiler fail to ignite a second time, check that the
external gas cock is open. If the problem persists, contact an
Authorised Service Centre. from Manual

Have you check for a signal from the air pressure switch ....As this could cause lock out.....
if it does not return to the normally closed position after the boiler switched off at the the END OF THE LAST CYCLE.
When the boiler is satisfied that the pressure switch returned to the normally closed position, It will energise the flue fan otherwise the boiler will go straight to lockout. The fan will then start and the ignition sequence and send a spark to the ignition electrode and allowing the gas to flow to the burner by opening the solenoid (CHECK SOLENOID IS WORKING). then there could be a problem with the FLAME RECTIFICATION FSD CHECK WITH A MULTIMETER A.C. CURRENT AND THE SIGNAL IS BETWEEN 5 TO 30 MICRO AMPS AND THEN CHECK THE POWER TO THE GAS VALVE....
Hope this helps

 

[breakdown]

does the burner light ? . If so are the spark electrodes still firing when burner lit before lockout ?

 

[Mikegriffin99]

The burner does light, then goes out as the green flame on light comes on. The fan and ignition both work in sequence, can't hear the spark after the burner has
lit, had to leave now, back in the week, so hate not getting it done !!!

 

[Mikegriffin99]

The burner does light, then goes out as the green flame on light comes on. The fan and ignition both work in sequence, can't hear the spark after the burner has
lit, had to leave now, back in the week, so hate not getting it done !!!

 

[John Patrick]

Thats the exact issue i'm having with my 27RFFi. Boiler starts, fan runs, ignition, gas admitted, fires up sparking all the time then fails after 10 seconds. shuts down with red light at reset standing. Is it the flame detection or the pcb?

 

[Dotty]

Moved off open forum.

 

[Billy Bob Bob]

simple answer to this fault ,if the polarity is not revered,the detection lead and electrode pass a continuity test the pcb has failed

 

[southcoastboile]

Have had this 3 times on this boiler. Has been pcb every time although I have made sure I have Fsp just incase. Would there be no resistance on Fsp/electrode gas man? Is that the same on every boiler?