To OP everyone is that busy with there own little vendettas about BG they have forgot the most important thing here namely the customer ,YOU.
wHY do you want to change one of the most reliable boilers ever made ok its 15 years old but all the working parts are readily avialable.
It is 78 percent efficient a new boiler will be up to 91% but this is not a constant and will drop down to about 85% at times or less ,so the savings are not going to be that impressive
If your set on changing it why not change it for a new classicHE it will fit straight back onto existing pipework and the flue hole will be the same ,thus cutting down on installation time . It could be off the wall and new one fitted in a matter of hours. With just the condensate and trvs if required to sort out.
As has been said BG do use a lot of outside contractors so why pay top dollar to BG when you could save thousands by cutting them out
BF . BG would charge you approx 1200 just to supply the boiler. so you would be talking around 3k to have them do it.
As mickeyg has said stick with what you have ,you are not going to get pay back on it and as i have said all parts are readily available and will be for a number of years as all the main components where still be fitted in boilers up to 3 years ago and some of them are still in the latest classics.
They will tell you to change it every year as parts are scarce this is basically a lie
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