What is a cold plug?

Lately I have been receiving calls from worried customers that there is smoke blowing back into their room from their open fire or stove. Here I explain what a cold plug is and how it can be fixed.

A cold plug in a chimney or flue happens when a mass of cold air sits inside the chimney and blocks airflow.

This block of cool, dense air stops warm air from rising up and out of the chimney, which in turn prevents smoke from escaping.

When a cold plug is present, lighting a fire can be challenging because the smoke, instead of going up and out, might back up into the room until the cold air blockage is cleared.

How can I stop it from happening?

To fix a cold plug in your chimney or flue, try these steps to warm up the air and get it moving:

1. Open the air controls: Ensure the air controls are fully open to allow airflow.
2. Light a Small Fire First: Place some kindling in the fireplace in a Jenga style with a gap in the middle, place a couple of firelighters in the middle, light it, and let it burn briefly before adding small logs. This small, controlled fire helps warm the flue gradually and establish a good draft.
3. Monitor the Draft: Once you see smoke pulling up through the flue smoothly, you’ll know the plug is cleared, and you can proceed to build your fire normally.

These steps should help clear out the cold plug, allowing your fire to burn cleanly without smoke backing up into your home.

Need further advice?

Please call me on 07568056121 or click here.

Female Chimney Sweep in Minehead, Taunton and Surrounding areas.