Why Is My Chimney Smoking?

A smoking chimney can take all of the pleasure out of a warm fire. Unfortunately, finding the cause of the smoke can be difficult, especially when it shows up inconsistently. But, we are a patient team, and will work with you to locate and address the source of the problem, no matter what it takes.

Is Your Flue Obstructed?

Anytime there is an excessive buildup of creosote due to an improperly maintained chimney system, air flow within the flue is restricted. When a chimney’s air flow is restricted, it is unable to function properly,and will have a difficult time pulling smoke up and out of the home. As a result, smoke often leaks or even billows back into the home.

What other types of flue obstructions are common?

If your chimney lacks a chimney cap or a chimney crown (or if either of these is damaged or deteriorating), the possibility of your chimney having obstructions of some kind is incredibly high. When these parts are installed and working properly, they act as a barrier, keeping animals, insects, water, foliage, and other debris out of your chimney. However, when they are missing or dysfunctional, debris can build up in your chimney, restricting air flow, and blocking smoke from properly exiting your home.

What do we do about chimney blockages?

If we do find that a flue obstruction is the cause of your smoke problems, we will remove the debris or creosote from your chimney using our specialized products, tools, and powerful vacuum system. We will also determine how the debris is getting into the chimney, and whether or not your crown or cap is in need of repair or replacement.

Having your chimney regularly swept and inspected for damage can protect you from the dangers and issues associated with flue obstructions, and should be a made a priority in your home. Read more about the importance of annual inspections and sweepings.

Is Your Air Supply Inadequate?

In addition to flue obstructions, there are other causes for inadequate air supply that can lead to a smoke problem in the home. One of the most common reasons for inadequate air supply is that houses are now designed to be incredibly airtight. In these airtight homes, the chimney often can’t get enough air from within the home to provide proper draft and remove excess smoke.

If inadequate air supply is the source of your smoke problems, there are a handful of things that could be occurring:

  • Closed Damper: Sometimes the source of your smoke problem is easily identifiable. It could be that your damper is not working properly – or just that you accidentally left it closed. Always make sure your damper is working properly and that it is opened before lighting a fire in your firebox. If it turns out that you need your damper repaired or replaced, give us a call. We’re happy to help.
  • Wrong Sized Fireplace Opening: When your fireplace opening is too big for the flue, you will most likely experience smoke problems – the reason being that an opening that is too large will allow more air into the fireplace than the chimney flue is designed to handle. When we find that the fireplace opening is overwhelming the flue and causing smoke problems, we typically install a fireproof shield in the firebox, decreasing its size without permanently altering it. We can also install doors that can narrow the opening.
  • Missing Chimney Cap: Many different outside factors can cause serious gusts of wind to blow into your chimney, pushing smoke down into your home. If your chimney lacks a cap, this could be the source of your smoke problem. However, it can be easily resolved simply by having a chimney cap installed by a Pristine Sweeps technician. We can help you find the best cap for your chimney and will make sure that it is fitted properly to prevent these gusts in the future.
  • Low-Quality Wood Fuel: If you have a wood-burning fireplace, your smoke problem could simply mean that you are burning wood that is not properly devoid of moisture. When a damp wood log is burned, the moisture burns off as excess smoke. Be sure to check your fuel source – only well-seasoned and non-treated wood should be fueling your fire.
  • Improper Overall Design: If your fireplace and chimney system were improperly designed, you are bound to have problems with efficiency and air conductivity. These flaws can include any number of things, such as improper chimney height, problems in the masonry, or just plain poor design. We can’t stress enough the importance of having your chimney and fireplace designed and constructed by a professional with experience and expertise. Trusting the safety and efficiency of your heating system to anyone else can leave you with an expensive but useless hearth.

What If My Chimney Has Major Design Flaws?

If we determine that your smoke problems are a result of design flaws, we will discuss your options with you at length so that you can make the right decision for your family and budget. Our chimney sweeps have years of experience building chimneys and fireplaces, and can help you design a system that will meet your needs and enhance your home.

Questions? Reach Out Now

If you have any questions or would like to schedule an appointment with the Seattle area’s best chimney technicians, call 206-574-8414 or get in touch with us online now. Thanks for choosing us!


A smelly chimney may be alerting you to a more serious problem. Let us do some troubleshooting so we can fix the right problem and fix it right!