I have a very old and very big coal to oil to gas converted steam boiler. Last winter I had to manually regulate water feed because, as I was told, the return water was not coming back fast enough and if an automatic water feed was on the level of water in the glass tube was much higher then it had to be. That resulted in flooding radiators on the first floor .
I was told that the entire system -boiler and pipes - has to be cleaned.
How do I go about it?
Boiler replacement is out of the question.
Isabelle