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.