Although the Vailant ECO Tech Pro 30KW was our most popular new boiler installation last year for many of our Edinburgh customers looking to upgrade their gas boiler, we now see the Glow-worm Ultimate 30c overtaking sales as our best seller before the end of this year. Why? Because it is a powerful 30KW gas boiler for £500 less! It is not the cheapest boiler, mind you. That position is still held by the 24KW Glow-worm Micracom at only £1600 excluding VAT but it is only installed in smaller properties requiring less power. It’s always best to speak to our heating engineer to find out what boiler power output you need for your property.