In order to keep your steam boiler running at maximum efficiency, it is recommended that you flush it at least once a month. Fortunately, flushing a steam boiler is a very simple task and is considerably less complicated than flushing other types of boilers.
Step 1 - Prep Your Boiler
Before you can flush your steam boiler, you'll need to make a few preparations. Begin this step by making sure the boiler is turned off. Next, place a large bucket beneath the boiler's bottommost spigot, then place some expendable rags around the bucket.
Step 2 - Flush Your Boiler
Having taken all the necessary precautions, you're ready to begin the flushing process. Open up your spigot and allow the dirty water to drain into your bucket. If at any point the bucket becomes full, close the spigot, empty the bucket, put the emptied bucket back into place and reopen the spigot. Alternatively, you could try keeping more than one large bucket on hand.
Once all the dirty water has been drained, you will notice clear water flowing into your bucket, at which point you may close your spigot and turn the boiler back on.