great early start for new boiler, Ruben turned up, got cracking, job done pretty quick. However, after he left, i noticed i could see daylight through flue vent wall, i fixed my self with chaulk. plaster on kitcen side left open, condensate pipe leaking, and now my raditors are noisey with debris sound,,as power flush not done properly!...manged to do a few bit myself, as no answer on phones for 40 minutes plus, & no reply to my emails!...they passed on radiator noise issue to Vaillant, but the rads arent Vaillants responsablity!...shame ive taken out the 10 year service plan with impra gas, i have no confidence. even the sales rep is not answering my calls or tetxts!.....wish i had read reviews earlier! my honest opinion, avoid, if you want a stress free experience.