Smoking fireplaces part 1: smoky fireplace startups

It is one of the most valued features in our homes. And all too often, the fireplace is labeled "non-working" and sits unused, because the homeowner doesn't know what to do about a smoking problem. Here I will show how most smoking problems can be handled relatively easily, with little or no expense. We'll cover:

 Here's a trick for monitoring smoky fireplaces: If you can't see the smoke spilling from the fireplace, shine a flashlight across the fireplace opening. The light reflecting off the smoke particles will make it easy to see. 

Smoky fireplace startups

The most common smoking troubles occur when the fire is first lit. If your fireplace smokes only during startup, but is okay after that, here are some possibilities:

Fireplace dampers

The purpose of the fireplace damper is to prevent heat loss when the fireplace is not being used. Don't forget to open it before you start a fire. But when the fire is completely out (usually sometime the following day), don't forget to close it. An open damper is like an open window, allowing huge amounts of heated air to escape.  When you are ready to light a fire, open the damper completely. Some people try to operate the fireplace with the damper closed partially, in an effort to get more heat into the room. But you won't gain much, if anything, by closing it partially, and you might gain a house full of smoke! No matter how you operate it, a standard open fireplace is not an efficient heater. Its purpose is atmosphere and entertainment. So forget about efficiency. Open that damper, and leave it open until the fire is out.

Cold fireplace flue

The flue will be cold when you first open the damper. This is especially true in fireplace chimneys built on the outside of the house, rather than up the middle of the house. A tall column of cold air in the flue will tend to sink, causing air to move down the chimney and into the house. So if you open the damper and feel cold air coming down the chimney, don't light the fire! If you do, smoke might be forced back into the house.  What you need is a tall column of warm air in the chimney. So first, prime the flue.

How to prime the fireplace flue

Roll up a piece of newspaper, light one end, and hold it way up in the damper opening. You might need to burn two rolls of paper. In a minute or so, you will feel the draft reverse, as the warm flue gasses start to move up the flue.  Once you have primed the flue, you can light the fire.  If you have a severe cold-chimney problem, and the newspaper trick doesn't seem to be working, try leaving the damper open for half an hour or so, allowing heated room air to gradually reverse the flow. Yeah, that's a lot of cold air coming down. But remember, this thing is for entertainment, not heat. Right? You can use the half hour to chill a nice bottle of champagne...

Blockages in the fireplace

Sometimes a smoking problem is caused by a partial or complete blockage of the flue. Animal nests, leaves and debris, or internal collapse of chimney brickwork can cause blockages. If you think your chimney may be blocked, or if you haven't had it checked by a chimney professional within the past year, make an appointment for a chimney check. Your chimney professional is qualified to identify and correct chimney blockages, and to check your chimney for other hazards as well. replace without it, before you start changing things. But a cap's important, so make necessary corrections and re-install it promptly.

Smoke Signals: Have a question about your chimney?