In article 5828cd64$0$36793$b1db1813$ca8b28d9
@news.astraweb.com, dennis@home says...

On 13/11/2016 19:59, bert wrote:

Well if you have £4500 sitting in the bank you'll be getting about £22
pa interest. So if you invest that money in a new boiler you will be
getting a better return on your money but you have converted a liquid
asset into a depreciating fixed one.

Would there be a better return on spending that £4500 on solar panels?

Nothing wrong with upsetting TNP as long as you don't actually think it
will help save the planet.

What's the insulation like?
If it's mostly the same age as the boiler, you'd invest
much less and get bigger returns by improving that &
leaving the boiler alone.