We can’t fault the quality of the job your guy left, and he was very tidy also, tell him well done! No, as a boiler operates, it produces a small amount of waste gas this gas turns into water, and is taken outside by the condensate pipe. Leak under your kitchen sink? leak through your ceiling? blocked toilet? At mcs we look after our new and existing clients alike, see below some of the special offers we have on offer at the moment. How do i use.