What is a damper fireplace? A fireplace damper is usually located just above the firebox in the masonry chimney. The purpose of it is to seal your fireplace shut when it’s not in use – preventing heated air from escaping up the chimney that can add pounds to your heating costs. How does a fireplace damper work? Read on…

Fireplace Damper Data

A fireplace flue damper lets you control the quantity of air flowing up the chimney when the fireplace is in use. You can adjust the damper to ensure the fire burns in the most efficient and safest way.

One of the key functions of the damper is to help ignite the fire – by opening the damper the air can get into the chimney so that the fire can start. There are ways to tell if the damper is open before you light the fire:

  • Feel for a draft – place your hand into the fireplace and if you can feel a draft coming down the chimney, this indicates the damper is open
  • Do a visual check – shine a torch up the chimney and if you can see the sky the damper is open – for a top-mounted damper you’ll see little pieces of metal sticking up at the chimney top if you go outside
  • Check the controls – a traditional throat damper will have a metal rod or knob – for a top-mounted damper a metal chain

Opening the Damper

How to open a fireplace damper is quite straightforward. If there’s a knob or metal rod near the fireplace or in the firebox, you’ll need to turn the knob clockwise as far as it will go, or push the rod all the way up.

If there’s a metal chain near to your fireplace this indicates the chimney has a top-mounted damper. To open it take the chain off the hook and let it go – the chain will spring up as the damper opens.

Closing the Damper

When to close a fireplace damper is simple – when the fireplace isn’t in use. Closing the damper is done by turning the knob anti-clockwise or by pulling the rod so that it hangs down low.

Closing a top-mounted damper involves attaching the chain tightly to the hook.

Fireplace with a chimney- outside

Frequently Asked Questions

Fireplace damper open or closed?

Bear in mind that operating the damper partially closed may block the passage through the flue and result in smoke coming into the room. The damper should be kept open until all the embers have died, and then the damper should be closed.

Compare an open damper to an open window – this lets large amounts of heat escape from your home. Keeping your damper closed when the fire isn’t burning will save you money in the long term.

Fireplace throat damper repair?

How to fix damper in fireplace is done by…

Initially cleaning the damper. For this job you’ll need:

  • Safety glasses and helmet
  • Protective gloves
  • Old clothes
  • Steel brush
  • Penetrating oil

After you’ve cleaned the throat damper by lying on your back inside the fireplace you can free any rusted plates by applying lubricating oil and letting is settle for a few minutes. Open the damper and get rid of any debris and deposits. It may be necessary to remove the damper if it’s bent or cracked by undoing the bolts and taking out the plate.

For older dampers you may have to remove the entire damper assembly and bracket – these might be bolted, welded, or cemented into the chimney. You’ll need additional tools such as a metal cutting blade or a small grinder to safely carry out this job.

You can then replace any damaged fireplace damper parts with exact fitting new ones.

Top sealing damper repair?

Top sealing chimney dampers tend to be more efficient as they seal off the chimney at the top. Sometimes they will become damaged or stick and this will need you to get on top of the roof to make any repairs.

You’ll have to open and close the damper by hand several times to loosen it – and it’s helpful to have somebody inside test that the chain is working properly. During winter months external dampers may freeze, but you can get a special device to help break any ice and dislodge it from a frozen damper.

For more serious damper repairs you just need to call in the professionals.