Best answer by Bumblebee
Hi there @Guardian
There are online suppliers, one I can think of is travisperkins.co.uk who deliver, surprisingly they can be cheap to buy from a lot of places
What I would recommend is getting a Gas Safe engineer on a electrician if an electric meter to fit it, checkatrade.com can find you the best reviewed at the best price locally, as it's far safer than doing than doing it yourself
Hope that helps!