Boiler guide is operated by holmes media (uk) limited registered in england & wales number 6873930 e&oe. Install a multi-fit gas saver when you fit your new boiler. We know that getting a new boiler installed is not a small decision, so in order to make the whole process as easy, stress-free and simple as possible, we created the basi way, a dedication to both excellent customer service and unbeatable services. We are worcester accredited installers (wai's) which means we are accredited to install.