Biasi boiler's , I don't know about the band A models , but we have fitted 363 of the cheap one's (2" were recently fitted for 2 oap's i got them to self purchase at B&Q discount on a wed') .
Can't fault the product have proved to be very reliable , some have been subject to some pretty heavy useage (abuse) , on 24/7 in commercial , install's never switch off , the old prisma s.r system's boiler's are the most reliable boiler's of there type we have ever put in , only 1 fault pcb 7 year's after install , spare's only spare's we buy with biasi name on it are pcb's , even went international with them 6 fitted in Spain , & we service them !!! the newer Band B biasi's I believe , (do) come with alloy recouperator's , bad idea in my view , B&Q still have old stock stainless steel boiler's if u are quick . My view's on biasi the company are somewhat different , I won't go there !! but I can't fault the product that we have used