To clean a steam boiler, a heating professional can:
- Use one pound of trisodium phosphate for every 50 gallons of water content.
- Heat the boiler to 180°F; hold at 180°F for two hours.
- Do not allow the boiler to make steam.
- After two hours, drain the boiler and fill with fresh makeup water. Water treatment chemicals should be reviewed before they are introduced into the boiler. Foaming agents that will interfere with steam action are of particular concern. Sodium carbonate (up to one pound for every 30 gallons) or sodium hydroxide (lye) (up to one pound for every 50 gallons) may be used.
- Check pH level after cleaning. It should be between 7 and 8.5. A small amount of cleaner may be added to adjust the pH up to the proper range.
- DO NOT use petroleum-based products in the boiler.