Cleaning of new wet return piping

Brad White_158

on the recent install at my Susan's house (HW not steam granted but old iron gravity lines) was to hook up a small electric HW heater with a circulator and small expansion tank with hoses to each circuit.

I pumped in a solution of hot TSP and water to each circuit, fitted hoses to the drain valves on the isolated circuit and fired her up. Let it run overnight. then flushed with a hose and clear water. Loosened up a lot of old stuff but had to get the gross stuff out before hooking up the new boiler.

If you were to just push in hot TSP it would take out a good bit of grease and oil but otherwise just sit there. I think you need to circulate it to get penetration. Maybe just a circulator and hoses to each end? Can you get a good circuit going, end to end?

Randy_25

Have just finished replacing the wet returns on a system, I did install valves at the ends of the return lines, unions thru out the piping for cleaning, and also valves at the boiler for isolating the returns for cleaning and flushing. I would like some input on how you would clean this system. I was thinking of isolating the boiler from the piping, mixing TSP and clean the piping then flush the lines. My thought was that this would help remove alot of the oil and pipe dope from getting into the boiler. I know that I'm going to have to skim and clean the boiler as well. The returns did last over sixty years. How would you clean this system?