Faulty biasi boiler

Kate...

I'm currently having problems with my biasi boiler. I'm getting intermittent hot water.

Earlier on today the water was running hot for a few seconds, then cold, then hot and then back to cold. I checked the boiler and the red and green light was flashing together and the pilot light kept going on and off. 

I didn't touch the boiler for a while but then when tried the hot water again later in the day the water seemed to be running hot again (although not as hot as usual). What could be the issue?

It did the same thing the day before too.

Thanks

macman

You haven't stated the model, but Google says that both green and red lights flashing on a Biasi appear to indicate a faulty fan or air pressure switch.
Last serviced when?