Dmc plumbing & heating today and let’s get started on your project! No survey ever comes back saying all is well! it certainly won't with an inaccessible manhole. Your most important choice is who installs and services your plumbing system! There are two other main types of boilers besides the combi version; system and standard boilers. We can’t fault the quality of the job your guy left, and he was very tidy also, tell him well done! You can report a problem.