Clean/skim GSA-125

The skim tapping is over here. You would need to remove the 1.5" plug. Might not be that easy to remove. Fairy eazy with an impact wrench and proper socket. You can try the following before skimming. Dump a bunch of 8-way boiler cleaner in boiler. Maybe 15-20 ounces. Run boiler unil it's starts to steam. Shut off, wait few minutes then turn boiler back on. Idea is to keep boiler hot but not steaming. Do this for an hour. Drain boiler. Refill and drain, refill and drain.... Until water is clean. This is not a replacement for skimming but it goes a long long way.

Here is the page from the instruction manual that you want. Forget the piping to floor drain, just use a bucket if you do get the skim tapping installed (it can be as little as a 6" or 8" nipple threaded into the skim port.)

Many of us have different opinions about this stuff, several of those opinions will work pretty well for you including Steam Doctor's above.

I would only add that if you are sure there is oil in the boiler that you can't get rid out without skimming, dump some of the "Squick" product in there which will bind with the oils and let them precipitate out where they can be drained. Otherwise the oil always wants to float in the water and can be very difficult to remove (without skimming).

I have tested the Squick product and it the only product I have seen that can actually let you remove oils without skimming.