Installing a Woodburning Stove in an Existing Fireplace

December 13, 2022


Installing a Woodburning Stove in an Existing Fireplace

Are you considering converting your old fireplace into a woodburning stove? If so, you’re not alone. This is really common and we deal with a lot of installations into an existing fireplace. There are a few things to consider when doing this and we’ve highlighted some of them below. Of course, you can get in touch to discuss your specific project and we’ll advise on the best approach for you.

Things to keep in mind…

Whether you’re opening up a fireplace for a woodburner, or have any empty recess ready to go, listed below are the main four things that you should keep in mind when installing a woodburning stove in an existing fireplace.

Chimney/flue size

First up is chimney size. Ensuring your flue liner is of the right size is essential as you can only fit a woodburner into a fireplace that has a class one chimney. More often than not this is the case, specifically if you had an open solid fuel fire previously. However, if you’re replacing a gas fire, you’ll need to check it isn’t a class two or a pre-cast flue, as these aren’t suitable for woodburning stoves.

Next, you’ll need to check the diameter of the fireplace flue. It’s essential that your woodburner is connected to the right size flue/flue liner. This is an essential part of ensuring your woodburning stove works and is safe to use. The vast majority of stoves up to 20kW require a minimum of a 6 inch flue diameter. 

If your chimney isn’t suitable for a woodburning stove for whatever reason, there’s always the option of installing a twin wall flue.

Distance to combustibles

The next thing to be aware of is making sure the fireplace chamber is big enough to allow the required distance from any combustibles – such as plasterboard or wallpaper that could catch fire. The specific distance required varies from stove to stove.

If your fireplace is made purely of brick, stone or any other non-combustible material, there is no regulation on how far away the stove needs to be placed. However, if there isn’t enough room in the space for air and heat to circulate it will affect the performance.

Heat output

The next thing to ensure you get right is the output for your stove, this refers to how much heat it produces. There are a few things to think about when choosing the output, from your room size and the age of your home, through to how warm you’d like your room to be. So, even if you have a large fireplace to fill, that doesn’t mean you should be opting for a large stove. Get in touch with our team of experts who will be able to help advise on the size of stove you require.


The final consideration is ventilation. Stoves need air to work and if there’s not enough ventilation in a room all sorts of issues can occur, such as smoke failing to rise out of your chimney and difficulty lighting your fire.

Make sure you check the air permeability of your room to make sure it’s suitable for a stove fireplace. If it’s too low, you may need to fit a ventilation brick.

Closing thoughts

Installing a woodburning stove in an existing fireplace isn’t a straightforward task. If you are considering this home improvement, speak to our team of experts. You can also get a free instant quote on our website.


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