How to Add Antifreeze to a Boiler

Written by kaydence small
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Boilers use a variety of fuels such as oil, propane, electricity and natural gas to create steam or hot water for radiators in the home. Boilers require the maintenance of adding antifreeze, as needed. When a boiler is properly maintained, the lifespan is often much longer. The majority of boilers are located outside the home, therefore it is necessary especially in winter to add antifreeze to prevent pipes from bursting.

Skill level:
Moderately Easy

Things you need

  • Bucket (1 gallon or larger)
  • Glycol antifreeze
  • Water
  • Sump pump

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  1. 1

    Turn off the boiler. Drain the boiler completely by opening the drain valve at the bottom of the boiler. Locate the area where you can add the antifreeze.

  2. 2

    Open the antifreeze and make a 50 per cent antifreeze and 50 per cent water mix in a bucket. If you have a manual available for your boiler, refer to it to see what amount it specifies to be used.

  3. 3

    Pump the antifreeze into the boiler. Add enough antifreeze to pressurise the system to 15 psi.

  4. 4

    Turn the boiler back on. Allow it to run about 30 minutes and then check to see whether additional water is needed. Your boiling system is now ready for winter.

Tips and warnings

  • Do not use car antifreeze in your boiler as this can cause damage to the boiler system.

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