Ariston MicroGenus 24 HE MFFI A91 Error code

[andypandy72]

So I have an A91 Error Code on the display on my Ariston MicroGenus 24 HE MFFI.

I have just replaced the PCB following problems with the boiler related to the much publicised A01 Error code.

So what happens is you turn the boiler on You get P24 on the display, the fan starts normally display changes to Pup then there is no flame ignition and the boiler cuts out and I get the A91 error code

I have checked all of the connections onto the PCB. I changed the EEPROM key to the correct one that came with the new PCB (although I note that the one I removed said V0.4 on it and the replacement has V0.3 on it (not sure if that makes any difference). To check the EEPROM card wasn't responsible I swapped the old one back in - no difference. New one is currently back on.

I have found that the power dial is not turning the boiler on and off I can see that the knob turns the switch on the PCB. Is the new PCB faulty?

There is no mention of this fault code in the user guide ( http://www.ariston.co.uk/uploads/doc47f9ff961b44b.pdf ) or the installation / maintenance guide ( http://www.ariston.co.uk/uploads/doc493d2c445580a.pdf ) and googling it doesn't help so I'm wondering what it is. )

UPDATE:
Just to check that I wasn't being a complete klutz I re-fitted the original PCB with the original EEPROM key - hey presto the boiler is working again ( albeit temperamentally with the A01 code popping up now and again). The ON-OFF dial is also working normally.

Can anyone suggest anything[/url]

UPDATE 2
Apparently it's the wrong board. Board supplied was 65100871 it should be a 65103422

 

[Steve69the69Gas]

Ring Ariston tech info.

 

[waterworks]

Hi the on off problem when fitting new board is that the potentiameter for the on/off switch needs altering before fitting it's a case of trial and error to find correct position one position will not allow it to turn on and another will not allow it to turn off. a pig to get all pots in correct position 1st time, the MK1 boiler is even worse to replace pcb.

 

[andypandy72]

Thanks. I had kind of suspected it might be something like that, but it's good to get the opinion of someone who has done it before. Also there is a wiring lomb that connects the main PCB to the recuperator PCB on the reverse side of the PCB inspection cover am I correct in saying that the excess cables are left inside the main PCB area or are they supposed to come out of the area on the LHS where the main bulk of cable come in? It felt like that was the way it was but wasn't 100% sure if that was how I found it.

 

[cakehole]

It was solved by using the correct eprom. it's easy to confuse the microgenus 28kw eprom with the microgenus HE28 one...