A chimney can smoke for a number of reasons ranging from problems with the chimney to operator error.
Here are some reasons that can cause a chimney to smoke:
1. A plugged chimney cap. If your chimney cap is plugged up with soot then there is no way for the smoke to exit outside and the only other way is into your home.
2.A dirty chimney can also cause your chimney to smoke. Soot build up is like cholesterol build up in a person. The more and more build up the harder and harder it is for the smoke to exit your chimney.
Since the soot is inside your chimney beyond your vision most people live with the motto "out of sight, out of mind."
3. Make sure the damper blade inside your fire box is opened. This is one of the most common things people forget to do when building a fire so don't feel embarrassed. Opening and closing the damper is very easy: Pull open, push closed.
4. Make sure the white ash underneath your fire grate is cleared aside. If the white ash piles up under the grate there is no chance for the red coals to radiate heat. It is the same as dousing a cigarette out in ash or pouring sand on a camp fire. Oxygen has no way of getting under the fire to help it breathe if white ash is under it and will cause it to smoke.
5. More on the fire grate, if your fireplace has a sunken fire box you need to raise your grate to be above the hearth floor to allow air to easily get under the grate.
6. Check to see the condition of your wood. If your wood is wet, not seasoned or has moss then your wood will smolder during your fire. Seasoned wood will have a moister content between 15-25%. Freshly cut wood has a moisture content of 50%.
Whenever you see smoke coming into your house throw in loosely balled up newspaper! Newspaper is the quickest way to create the proper BTU's to push the smoke up your flue. Make sure that any central heating, appliances etc that may be causing negative pressure in the house is off as it will suck smoke back into the house.
7. Make sure you prime the flue. Your chimney is like your car in the winter: you need to warm it up before you drive or else it will stall. Use wood kindling and lots and lots of newspaper to heat up your flue before you put on a log. REMEMBER smoke is very lazy and will look for its easiest way out. Always keep newspaper on hand and throw it on your fire the moment you see smoke entering your living room.
8. Make sure there is nothing blocking the entrance to your flue. If you do not have a cap on your chimney things from outside can come in through the opening of your chimney and potentially block the passageway that smoke needs to get out.
The reason there is water dripping in your chimney is because there is no rain cap arrestor on your chimney. If you had a hole in your roof and ceiling would you cover it up? Why not your chimney? Remember this is an opening where water can come in a cause a lot of damage to your chimney and your pocketbook.
There could be a few things wrong to make your damper not open or close.
1) The damper could be rusted because of water dripping in from not having a flue cap. This is a very common problem. Squirting DW-40 in any joint area may help loosen up your damper. If that doesn't work get a hammer and hit the damper blade. This may free it up. If none of these work then removing the damper and putting in a top damper is your next option.
2) When the chimney was built there may be excess mortar interfering with the damper blade. Getting a hammer and chisel and freeing up the area being affected may help out.
3) The smoke chamber behind the damper blade may have an extreme amount of soot and ash that may be blocking the path of the damper blade. Cleaning out behind the damper to free up that area may help you out.
4) If you have a prefab chimney your damper may be dislodged, chain may be disconnected, etc. Realigning, putting back in place or whatever may be required may solve the problem.
When your fire back wall flakes in places is called spalling. Spalling occurs when water soaks into a brick and much like shale and slate a brick flakes off in sheets. Once a brick begins to spall there's is not much you can do about it but fix the problem where water may be entering. Any attempts to cover up any spalling only acts as a band aid and will only be temporary.
Any strange odors that are coming from your chimney may be the result of a several things:
1) Creosote may be building up in your chimney. If it smells like bad barbecue and you are experiencing headaches, nausea etc then you may have creosote.
2) Leaves may have fallen into your chimney and settled behind your damper blade in the smoke chamber and is beginning to mulch. This combined with damp ash and soot may produce a bad odor.
3) Water may be collecting behind the smoke chamber and give your chimney a damp smell.
4) If any animals entered your chimney they may have left "presents" for you in your smoke chamber.
5) If any animals have entered your chimney and were unable to get out may have passed away. The smell may be from this.
Cold air is coming into your chimney because your damper may be open. Closing your damper will keep a good portion of cold air from entering your chimney. If your damper is warped, frozen or missing then installing a top damper is the perfect solution. Top dampers are 100% air tight and are lifetime guaranteed.
There are many factors that can prevent your chimney from drawing correctly.
1. The chimney can be dirty and needs to be cleaned.
2. The flue cap on top could be clogged and not allowing the smoke to escape.
3. If there is no chimney cap/arrestor leaves and branches could have fallen in the flue creating a blockage.
4. Heavy winds can prevent smoke from exiting your chimney.
5. Extremely cold weather combined with a fire that is not producing enough BTU's to push the smoke out.
6. If the flue hasn't been properly primed making it difficult to push smoke out. Think of your chimney as an old car that needs to warm up before you drive it.
7. If the fireplace has a sunken firebox that can prevent proper airflow to the fire itself and not producing the heat it needs to push any smoke up the flue.
8. If there is excess ash under the grate will douse out the red coals that develop and affect the amount of heat the fire is producing.
9. The chimney is below the pressure zone
10. Stack house effect where the pressure inside of the house is off.
11. An appliance causing negative pressure
12. The most common reason is because the damper is not opened.