Hi all, I want to change the condensing boilers because it's about 20 years-old now. I also want to power flush the whole heating system and have 6 new thermostatic radiator valves installed. There will be a new double radiator in the hallway which the size is about 600 x 600. As the old cylinder needs a new pump and valve(?), also with the immersion heater. A Magneclean will be also included. Someone recommended the Boxi Solo 15 HE to me. Is this a good boiler? How much will cost me for the installation? Thanks for any suggestions.