8 Tips on How to Correctly Apply Boiler Antifreeze

Various methods exist to correctly apply boiler anti-freeze. Before you begin this process, be sure it is absolutely necessary to apply the anti-freeze and that no alternate methods will work better to accomplish your objective of protecting the system from freezing.

Removing Existing Water from the System

Before adding the anti-freeze, prepare your system by removing all water from the boiler and lines. 

  • Drain the boiler using the drain valve located near the bottom of the boiler
  • Open all bleeders on heating lines and continue to drain at the boiler
  • If some of your heating lines are located below the boiler, you may have to force out some water with air pressure

Adding Anti-freeze

Once the lines and boiler are drained, add only mobile home anti-freeze to the system. 

  • Close the water valve near the boiler that feeds house water into your boiler system
  • Find a location for the anti-freeze to be forced into system, possibly the boiler drain valve
  • Begin to pump anti-freeze into the boiler. It will take approximately 10 gallons for a 2800 square foot home depending on heating system configuration
  • Add enough anti-freeze to pressurize the system to 12-15 psi
  • Bleed the system until anti-freeze squirts out from each bleeder location

Your system is now protected from freezing down to the freezing point temperature of the anti-freeze mixture you used.