How To Avoid Smoke Indoors from Freestanding Wood Heaters

When a freestanding wood heater, fireplace or inbuilt is not operating correctly, it can push smoke into the home instead of venting safely outside. Several reasons include wood moisture, improper combustion, negative pressure, and kindling/wood placement during startup that can lead to smoke entering the home. The following article explains why smoke is entering your home and some ways to stop it, ensuring your wood fireplace works safely and efficiently moving forward.  


Why Is Smoke Entering My Home From My Wood Fireplace?

When a wood heater is burning correctly, little to no smoke will enter your home when you open the door. However, if the unit is filled with cold air or if the unit is not working correctly, it may push smoke back into the home. 

Note: North American models shown

In addition, here are some more of the most common causes of smoke entering the home:

  1. Combustion Air/Negative Pressure

    • If the house itself has negative pressure, it will want to pull air down the very same chimney system which is trying to remove the smoke from the firebox which will result in smoke entering the room.

  2. Incorrectly Burning the Unit/ Poor Combustion

    • If the wood stove is too cold, overloaded early, or the wood is not burning, you may get smoke in your home.

  3. Using Wet Wood

    • Wet wood cools your fire, and more energy is needed to get it to combust. Too much wet wood and the fire may start to smoke.

  4. Improper Kindling/Wood Placement

    • Not allowing airflow between pieces can prevent the kindling/wood from catching correctly and result in smoke buildup in the unit

  5. Adding Too Much Wood Too Quickly

    • Allow the existing wood to fully engulf in flames before adding more wood. Adding more wood is like adding water to the fire and requires more energy to dry the wood and begin burning. Too much wood too quickly can stifle the fire and result in smoke buildup in the stove

  6. Restricting Airflow Too Early

    • Fires require lots of air to get going and should only be restricted once a strong bed of coals has been established. Restricting airflow too soon can cause smoke to build up and spill into the room when the door is opened.

  7. Engaging the Catalyst Too Early

    • If you have a catalytic unit engaging the catalyst too soon may cause the fire to be stifled and begin cooling down, resulting in smoke buildup in the unit that can spill into your home

  8. Cold Vent Pipe or Stove

    • A cold stove has a pocket of air within the vent pipe and stove itself. This cold air pocket causes cold air to descend into the firebox and into homeonce the door is open creating a negative pressure that pushes smoke into your home. Once the stove and venting are sufficiently warm, the stove will begin to draft properly, reversing the air flow and push the smoke up and out the venting.


How To Fix Smoke Entering My Home From My Wood Heater?

When a wood fireplace is burning correctly, little to no smoke will enter your home when you open the door. However, if the fireplace is not working correctly, it may push smoke back into the home. Here are some of the most common fixes to the typical causes of smoke entering the home
 

  1. Combustion Air/Negative Pressure

    • Generally, heater performance problems caused by negative pressure can be corrected by introducing make-up air into the room where the unit is installed.  A greater supply of combustion air will balance out negative pressure and allow the fires flue to draw. Before investing in a permanent solution, try opening slightly an outside door or window near where the unit is installed.  If the house is airtight or negative pressure is a problem, the fire will burn better with a door or window slightly ajar than it will with the outside doors and windows closed. Opening a door or window is not a long-term solution, but it can help diagnose the problem.  A good long-term solution will bring air into the house without creating cold drafts or wasting energy.  The best option is an outside air duct to supply fresh combustion air to the fireplace.

  2. Incorrectly Burning the Unit/ Poor Combustion

    • Always ensure there is a hotbed of coals in the fireplace, and any existing wood is fully engulfed in flames before adding additional wood. New pieces of wood will cool down the fire as the water content in the wood must evaporate before the wood can start to burn. The process of evaporating water into steam requires energy from the surrounding fire and therefore cools the overall temperature of the stove. Adding too much wood too soon or not allowing proper airflow around pieces can stop the fire from fully engulfing the wood and lead to smoke entering the home

  3. Using Wet Wood

    • Only use seasoned wood with a moisture content of less than 20%. Wet wood or wood with too high a moisture content requires tremendous amounts of energy to dry and begin combustion. Without that energy present (especially during startup), this wood is likely to cool down the fire significantly, leading to smoke. 

  4. Improper Kindling/Wood Placement

    • Always stack kindling and wood in such a way that it allows significant airflow around the exterior of the entire piece of wood. This airflow gives space for flames to come into contact with the wood and air to circulate and warm up the piece to the point of combustion.

  5. Adding Too Much Wood Too Quickly

    • Modern wood heaters are highly efficient and burn for a long time. In order to get to this stage, they require a more extended startup period than old wood fires. Like how you need to warm up a diesel engine before using it, you need to warm up modern wood fireplaces, freestanding heaters & inbuilts. Slowly adding wood and building a strong bed of coals is essential too much wood too fast, and you will stifle the fire and cause smoking. 

  6. Restricting Airflow Too Early

    • Like adding too much wood too quickly, reducing the airflow too quickly restricts the fireplaces' ability to create a strong bed of coals and, therefore, its ability to run efficiently. Airflow restriction should only take place once the unit is warm and all wood inside is fully engulfed. 

  7. Engaging the Catalyst Too Early

    • Similar to the points above, engaging the catalyst decreases the temperature and airflow within the fireplace, so it should only happen once the stove has been running for a while and is fully up to temperature 

  8. Cold Flue Pipe or Freestanding Heater

    • To stop a cold freestanding heater or cold pipe from pushing smoke into your home, you can try priming your flue by burning a piece of newspaper. Rolling a newspaper up into a cone, lighting, and placing close to the damper will provide enough warmth to prime the flue and stop cold air from smothering your fire. All you need to do is locate the damper on the inside of the unit, open it, and place the burning newspaper as close to the hole as possible. Estimated burn time should be between 2-3 minutes to effectively prime the flue.


Still Getting Smoke in Your House? 

If you have tried all the above steps, are letting your fireplace heat up, there could be an installation issue, and you will need to book a service call from your local Regency fireplace dealer. 

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