New Boiler Acting as Scouring Pad?

if there is dirt in the return piping and it hasn't been flushed out, it can migrate in to the new boiler. beyond that it should behave the same as the old boiler if it is installed properly and the system is leak free.

the oils from the new boiler and piping will have to be removed by skimming the boiler a couple times. the surging the oil will cause will cauyse the boiler to throw liquid water out in to the system.

but you should be flushing wet returns when you install a new boiler anyhow…

Why aren't new boilers cleaned by supplier?

Break open a steam radiator; pretty clean inside? Somehow decades of rust are cleaned by steam and end up in boiler? Perhaps new radiators should be anodized?

Gotta get the Splunck expunged. ..Mad Dog

My opinion is the comment isn't literal.

You disturb all kinds of piping etc when you remove the old boiler and install the new one. That can stir stuff up / knock stuff loose.

That's my interpretation.

Disagree. Much of the oil is from the machining products of the new boiler sections and drilling and tapping the various tapings. Cast iron is somewhat porus especially the rough interior of the boiler sections and holds the oil and in addition the boiler sections are full of sand from the cast iron poured into a mold that contains sand. How do you think the hollow sections are made?

The amount of cutting oil from the piping that is field installed is quite small.

I installed a Smith 28 series boiler once and when rigging the sections into position a lump of sand the size of your fist fell out of one of the push nipple ports that was oily.

Best way to clean it up is to boil it out and skim the boiler with TSP or washing soda.

The piping gets disturbed during the install. Some including @Gordo recommend a ball valve on the return line connection near the Hartford loop and drains installed on the return lines so the boiler can be run and the condensate wasted to a drain otherwise known as a "no return flush" Some boiler mfg. recommend (or used to) this method.

A ball valve is OK, and I will use in a pinch, but a Gate is my valve of choice just before the last 90 degree elbow in to the Hartford Loop Tee for Power-Flushing of the Wet Returns. Every installation gets one, period. The Teflon rings that surrounds and seals the chrome ball, don't last long in the steam condensate bath.

What I do like to do and it helps alot, is to plunge my cut pipe and nipples like a musket or Shotgun with a clean rag & rod to push out any remaining oil & shavings. This 30 second trick can save hours on Flushing and skimming.

Of course. Old boilers, piping and systems settle in to a status quo over the years. Cutting the pipes connected in to the boiler & demo'ing the boiler may break a little crust & scale off inside the pipe walls, but that is a minor contributor to what's flowing back to the boiler.

The brand spanking new boiler cranking out Dry Steam, fresh, oxygen-Rich make up water WILL scour the crap outta the old mains, risers, radiators and especially the Wet Returns.

As a plumber, when you cut out a large section of old, sewer or drain pipe, you'll see the disruption & removal of the slimy, greasy flow path with new, smooth & clean pipe will cause the detrius upstream to break loose as nothing is holding it in place any longer and a self scouring effect occurs. Mad Dog

I just repiped this boiler that was not installed correctly or maintained. Once we got to repiped and actually were producing dry steam the wet returns were wasted to drain and to help get sediment out. There were other issues on the wet returns because of water collection from unsupported pipes causing pooling of water and sediment. Needless to say we also ended up replacing condensate lines. The system was able to run for a week and get flushed out a few times. Skimming the boiler is a must for install. This job still has more issues with radiators, but we were able to shut off the problem ones until they can be addressed after the holidays

You have mud ,you have steam leaks … Solids . The minerals behind in the system when the water is boiled and lost out of the system …The solids in the water is left behind …

The minerals in the water stays behind when the water is boiled off …The system in design should prevent water loss .Air vents should close when steam enters . If you loose steam, you will need to add more water which will add more minerals (solids , mud) . Mud tells me , there are steam leaks in the system…