i would have been nice to know the following
boiler make & model
gas council number [if possible]
example
ariston microgenus mffi HE ??
GCN 47-116-??
its very difficult to diagnose fault codes without knowing which make & model of boiler that particular fault code refers to
if fault code A 01 was on an ariston boiler for example
just need to press reset button
if you dont know where the reset button is on boiler
look in user guide
if you dont have a user guide
i would have directed you to an appropriate website you could have downloaded information from for your particular boiler make & model
example
http://www.ariston.co.uk/uploads/doc47f9ff961b44b.pdf
manwithnoname
April 2012