No, your comment have merit and I'm sure you don't exaggerate.
Yes, about the phone lines; there are 15 into the customer care centre and sometimes we even had to use mobiles to get in and out.
Mostly it was condensates frozen when I was there before Christmas and I sat in on a day of calls. Was there last week and there were two additional new people taking calls in a much more relaxed state. Even the sales girls were trying to help people in the freeze up by taking calls. I think it happens to most manufacturers in a freeze. In my personal opinion I look upon that as an installation fault but it simply eats up the lines, I believe Worcester shut their's the year before.
I spoke to the southern service manager about your problem who is aware of the agent issue but he tells me there are 4 or 5 that could be called to cover EN9. I will remind him and also he is now a member of the cc forum so watches the posts, I'll direct him to this one. If you could find any paperwork or the address plot number etc we could trace it. PM me.
I really now only service my old customers who have Neatheats, Baxi FS and WM boilers so it was interesting for me to strip and reassemble the Linea One which is a bigger Unica with bells and whistles.
With a decent toolkit it was fine except for the rim of the plate which is sharp like many (Intergas excepted).
Unpin and move the hot and cold and there's more room to get the plate out.
If you get one with 12mm clearance on the right and have to take the burner out it'll be 'interesting'. I'm going to set that one up for myself.
As for not honouring the warranty - not in my experience. I've been to jobs with the company replacing a boiler that was not needing replacement due to fluctuating gas pressures plus pumps, plate exchangers etc due to dreadful installs and they bite the bullet. I tell you I wouldn't do it.
You know probably better than me all boilers have quirks and idiosyncrasies which once you know about you just work round. If they didn't they wouldn't have the small print 'subject to change at short notice' somewhere in the instructions. I just wish all changes were for the better.
BTW about sealing the flues on the park homes; I don't think there is one manufacturer who states the dress trim is a satisfactory seal is there? I know our guys are instructed to note them but not cap them off.
I'll keep doing this unless I catch a rocket and told otherwise but I wish all manufacturers would admit to representation on a forum, particularly the CC.