Posted by Christopher Tapia, Luxury Fire on 2nd Dec 2025
How Does a Wood Fireplace Insert Work?
When homeowners visit my showroom or call Luxury Fire, one of the first questions they ask is:
"How exactly does a wood fireplace insert work?"
It’s a great question — and after helping over 3,000 customers choose, install, and use wood inserts in the last 20+ years, I’ve learned that most people misunderstand how these systems truly work.
This guide explains everything in simple language, backed by professional experience, real case studies, and the most common issues homeowners face before switching to a wood insert.
What Is a Wood Fireplace Insert?
A wood fireplace insert is a high-efficiency wood stove built to fit inside your existing masonry fireplace. Unlike an open fireplace, which loses most of its heat up the chimney, a wood insert:
- Seals the fire behind a glass door
- Connects to a stainless steel chimney liner
- Burns wood far more efficiently
- Pushes heat into the home instead of losing it
In simple terms: it turns your old fireplace into a powerful new heating system.
Why a Wood Insert Works Better Than an Open Fireplace
An open fireplace actually
A wood insert fixes this by:
- Containing the fire in a sealed chamber
- Controlling oxygen intake
- Reburning smoke for higher efficiency
- Radiating and blowing heat back into the room
You get more heat, less smoke, and dramatically lower heating bills.
How a Wood Fireplace Insert Works (Step-by-Step)
Step 1: Load Dry, Seasoned Wood
Dry wood burns hotter, cleaner, and with almost zero smoke. Ideally, moisture content should be below 20%.
Step 2: Air Enters Through Adjustable Vents
You control the fire with the air control. More air = stronger burn. Less air = longer burn time.
Step 3: Secondary Burn System Re-Ignites Smoke
Modern inserts inject hot air into the top of the firebox to reburn smoke, producing more heat and reducing creosote.
Step 4: A Stainless Steel Liner Pulls Smoke Upward
The insert connects to a 6” (or sometimes 5.5”) liner that:
- Keeps smoke sealed
- Improves draft
- Protects the chimney
Step 5: Heat Radiates Through the Glass and Metal
Inserts produce radiant heat, convection heat, and stored heat.
Step 6: Optional Blower Pushes Heat Into the Room
Blowers significantly increase heat output and are recommended if you're buying the insert for whole-home heating.
Key Features of a High-Quality Wood Insert
- High efficiency for long burn times
- Large firebox for stronger heat and longer burns
- Big glass window for ambiance
- Strong build quality and long warranties
Examples of Wood Inserts We Recommend
Here are some of the models we commonly suggest depending on the homeowner’s needs:
- Regency Ci2700 – Maximum heat & long burn times
- Pacific Energy Alderlea T5 – Extremely efficient with strong blower performance
- Stûv 6 – Minimalist, modern, perfect ambiance
- Spartherm L800 – Large panoramic glass & European engineering
How to Size a Wood Insert Correctly
To ensure a wood insert fits your fireplace, you'll need these measurements:
- Front width
- Rear width
- Depth
- Front height
- Height at 19” depth
Send photos or measurements to hello@luxuryfire.com and we’ll confirm the fit for you.
The #1 Misconception About Wood Inserts
Bigger inserts do NOT overheat your home.
The amount of wood you load determines the heat — not the size of the box.
This is why I always recommend getting the largest insert that fits.
Why Homeowners Switch to Wood Inserts
1. Their Chimney Needs a New Liner
Instead of only repairing the chimney, you can invest almost the same amount into a wood insert that gives you a brand-new heating system.
2. High Heating Bills
We’ve seen customers cut their winter heating bills by 50–75%.
Real Customer Success Story
We helped an elderly couple who were spending $1,500 a month on electric heat. Their old fireplace made things worse by pulling heat out.
After installing a wood insert, their next winter bill dropped to only a couple hundred dollars.
They finally had a warm, comfortable home — and a beautiful fire to enjoy.
Do Wood Inserts Cause Smoke in the House?
No. Wood inserts have sealed doors, so the smoke can only go one direction: up the chimney liner.
If you ever experience smoke:
- Check the chimney cap
- Start with small, hot fires
- Use dry wood
- Warm up the liner
Maintenance Is Simple
- Annual chimney sweep
- Check the door gasket every few years
- Remove ash as needed
Should You Add a Blower?
If you're heating your home: yes.
If you only want ambiance: optional.
How Much Heat Can a Wood Insert Produce?
- Small: 20,000–45,000 BTU/hr
- Medium: 45,000–60,000 BTU/hr
- Large: 60,000–85,000+ BTU/hr
Final Thoughts
A wood insert is:
- A heating system
- A money saver
- A beautiful upgrade to your home
- A reliable backup heat source
And with modern technology, wood inserts are cleaner, more efficient, and easier to use than ever.
Ready to Choose the Right Wood Insert?
Call me directly: 800-969-9592
Email: hello@luxuryfire.com
Explore our most trusted inserts:
Whether you want maximum heat, long burn times, or stunning ambiance, we’ll help you choose the perfect model.
Christopher Tapia, Luxury Fire, 10 plus years of experience in the fireplace industry
