Great group here , fast and reliable ! The vertical flue adaptor is used with the vertical flue terminal and suitable for condensing boilers. Wondering about how energy efficient your new boiler will really be? It's worth having a quick look at who looks after what inside and outside the boundary of your home on our. Kurt is an absolutely excellent plumber and a wonderful human being besides! Designed for the initial stage of a building project, be it new build or refurbishment, this.