I had one of these boilers fitted today, I am also 68 and got it through a government scheme. It is very noisy, it has the sort of sound my old boiler made when I was running water. It is in a GF utility room with door and there is a long kitchen between it and where I am sitting with my laptop. I then went up stairs and I could hear it slightly still in the bathroom but thankfully not in my bedroom. I turned my boiler off an hour ago and the noise continued for at least 15 minutes then suddenly silence. I think that if I had the TV on or some music I wouldn't notice is but I like sitting in peace and quiet. They are coming to install the installation next week so I will have a word them. I feel like you, my old boiler was not efficient but it was quiet unless water was being tun.