How to Correctly Apply Boiler Antifreeze

a water heater

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

Step 1 - Remove Existing Water from the System

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

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

Step 2 - Add Antifreeze

Large jugs of chemicals

Once the lines and boiler are drained, add only mobile home antifreeze to the system.

  1. Close the water valve near the boiler that feeds house water into your boiler system.
  2. Find a location for the antifreeze to be forced into system, possibly the boiler drain valve.
  3. Begin to pump antifreeze into the boiler. It will take approximately 10 gallons for a 2800 square foot home depending on heating system configuration.
  4. Add enough antifreeze to pressurize the system to 12-15 psi
  5. Bleed the system until antifreeze 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.