Ariston Micro Genus Type C Boiler. Ignition Fail Lock Out .

[abced650]

Ariston Micro Genus Type C Comination Boiler .Type G.C.N 47 116 14/15
Fault: Boiler lights and burns normally for 7 seconds and then shuts down and displays "Ignition Failure Lockout " red led.Using natural gas.
Press the reset button and the boiler fires up and each time cuts out after 7 seconds aprox ,whether on ch and or domestic.
New pump ,diaphagm (main flow switch),overheat detection electrode,boiler combustion chamber lining, gauge ,main flow switch,reed system.Fuses both ok.Pump set on maximum speed.Hot water circulates in ch system,pipes get warm.
System bled several times at pump and reserve tank .Bleed caps on Reservoir and pump undone two turns.No central heating connected ,just 5 meters of 22mm pipe loop .Water pressure at 2 bar and steady.
Followed start up procedure.Clean water in system.Only using for domestic.The boiler was working perfectly for a couple of weeks after fitting the new parts .
I would appreciate advice on this please .

 

[mysteryman]

You need to check the ionisation. This is only in microamps. Check that the ionisation lead is sound, clean, and dry, and that it is not touching bare metalwork. Check the ionisation electrode ceramic for cracks and/or damp.

 

[Agile]

You have a gas/combustion related fault which we dont give advice about on the open forum.

The only good advice is to get a competent gas registered boiler engineer.

Tony Glazier

 

[abced650]

I have fitted a new ionization sensor /detection electrode and checked the continuity and resistance of the new and old sensors and they are both .4 ohms. The wiring lead from the sensor to the pcb is also about .4 ohms. The flame is heating the sensor. Could it be anything other than the pcb?

 

[Agile]

Replacing electrodes involves opening the combustion chamber which we dont advise as a DIY job.

The PCB detects the flame but if thats faulty its not a DIY job either to change it as it needs some gas adjustments when fitting a replacement.

Tony