Ferroli modena 80e HELP !!!!?

hi all,
i have a ferroli modena 80e in the house i have just brought, within the past 3 months i am sick of reseting the boiler as every now and then i will look at the boiler and see the red warning light, (it seems to annoy the missus more tho lol) a quick reset seems to do the trick and will work for maybe half an hour when the ch is being used or half way through running a bath !
i have also found that the pressure drops right to nothing but when i run the hot water the pressure goes up to around 2.5, Can anyone advise all comments greatly appreciated