A small fireplace insert can bring real heat and a modern flame to a fireplace most people assume is too tight to upgrade. Shallow fireboxes, narrow openings, and older fireplaces with odd dimensions show up in our consultations all the time. In most cases, there’s an insert that fits.
This guide covers how to measure a small fireplace, which fuel types work best in compact openings, and the questions our team asks to find the right fit.
Why Small Fireplaces Are Worth Upgrading
Many older homes have compact fireplaces that were never meant to heat much. They look charming but pull warm air out of the room when in use. A properly sized insert changes that. It seals the opening, creates a closed combustion system, and turns the fireplace into a usable heat source.
TheU.S. Department of Energy notes that a well-fitted fireplace insert can function nearly as efficiently as a stove. That’s a big leap from an open fireplace, even a small one.
How to Measure for a Small Fireplace Insert
Every insert has a minimum opening size. Before you fall in love with a model, grab a tape measure and record these five numbers:
- Front width across the opening at its widest point.
- Rear width across the back wall of the firebox. Many fireboxes taper toward the back.
- Height from the hearth floor to the top of the opening.
- Depth from the front edge to the back wall, measured at the center.
- Depth at the top, since sloped back walls can reduce usable space.
Take a photo of the fireplace with the tape in view. It helps our team narrow options quickly. We always confirm measurements in person before an insert is ordered, because a fraction of an inch can decide which models fit.
Best Fuel Types for Fireplace Inserts for Small Fireplaces
Each fuel type has strengths when space is tight.
|
Insert Type |
Fit in Small Openings |
Heat Output |
Ambiance |
Power Needed |
|
Gas insert |
Wide range of compact sizes |
Strong, adjustable |
Realistic flame at a switch |
Varies by model |
|
Electric insert |
Fits the shallowest openings |
Supplemental |
LED flame effects |
Yes, standard outlet |
|
Pellet insert |
Needs moderate depth |
Strong, thermostatic |
Real flame |
Yes |
|
Wood insert |
Needs moderate depth |
Strong |
Classic crackle |
No |
Small Gas Fireplace Inserts
Gas is the most popular choice for compact fireplaces. Sealed direct-vent gas inserts come in a range of sizes, and many models in ourgas inserts collection are designed with smaller openings in mind. Heat & Glo offers inserts like the Escape, Provident, and Supreme in multiple sizes, so our team can match the firebox to your opening.
Electric Inserts
When a fireplace is very shallow, an electric insert is often the easiest fit. The SimpliFire Electric Insert plugs into a standard outlet and needs no venting. It provides supplemental heat and a flame you can enjoy year-round. Ourelectric fireplace insert guide covers the details.
Pellet and Wood Inserts
Pellet and wood inserts need a bit more depth, but compact models exist. The Quadra-Fire Expedition I wood insert and Quadra-Fire Santa Fe pellet insert are two options we often consider for smaller masonry fireplaces. See ourpellet stove insert guide for more.
Common Small Fireplace Challenges (and How We Solve Them)
Shallow Fireboxes
Shallow openings are the most common issue we see. Some gas inserts are designed to sit partially forward onto the hearth, gaining usable depth. Electric inserts are the next option when depth is very limited.
Tapered Back Walls
A firebox that narrows toward the back can block an insert that fits the front. That’s why we measure both the front and rear width.
Short Openings
Low openings limit height. Some inserts have a lower profile, and a new surround panel can clean up the look where the insert meets the opening.
Uneven or Damaged Fireboxes
Cracked or uneven fireboxes should be addressed before an insert goes in. Our factory-trained technicians evaluate the condition during your consultation.
Small Fireplace Insert vs. a New Small Gas Fireplace
If your fireplace is too tight for any insert, or you want to relocate it, a new built-in unit may be the better path. Our guide tosmall gas fireplaces for compact spaces explores built-in options, andgas fireplace sizing explains how to match heat output to room size.
What to Expect During a Small Insert Project
Here’s how the process typically works with our team:
- Consultation. We look at your fireplace, talk through fuel options, and take measurements.
- Model selection. We show you every insert that fits, along with surround panel and trim options.
- Installation. Our factory-trained technicians set the insert, connect the venting, and finish the surround.
- Walkthrough. We show you how to run the remote, adjust the flame, and care for your insert.
Small fireplaces sometimes need a little creativity, and that’s where experience pays off.
Tips for Getting the Most From a Small Insert
- Add a blower. A blower pushes heat into the room, which matters even more with a smaller firebox. Read our guide to choosing agas fireplace insert with blower.
- Choose the right surround panel. A slim, dark surround can make a small insert look larger and more modern.
- Use zone heating. A small insert can keep a main living area comfortable while you lower the thermostat elsewhere.
- Plan annual service. A yearly tune-up from our factory-trained technicians keeps any insert running safely. Seewhat a professional tune-up includes.
Safety Notes for Compact Fireplaces
Gas inserts are sealed units that draw combustion air from outside and vent exhaust back out, so they don’t compete for room air. Keep working carbon monoxide alarms on every level of your home, as recommended by theU.S. Consumer Product Safety Commission. A properly maintained gas insert produces mainly carbon dioxide and water vapor; carbon monoxide only becomes a concern when combustion is incomplete due to a malfunction or lack of maintenance.
Not sure what fits your fireplace?Request an estimate from Fireside and we’ll measure your opening and show you every small fireplace insert that works.
Frequently Asked Questions
Can you put an insert in a small fireplace?
Yes, in most cases. Gas inserts come in compact sizes, and electric inserts fit even very shallow openings. We measure your fireplace to confirm which models fit.
What is the smallest fireplace insert?
Electric inserts generally fit the smallest and shallowest openings because they need no venting. Among gas inserts, several compact models are designed for smaller fireboxes.
How do I measure my fireplace for an insert?
Measure the front width, rear width, height, depth at the center, and depth at the top. Our team confirms these measurements before ordering.
What if my fireplace is too shallow for an insert?
Some gas inserts can sit partially forward onto the hearth. If depth is very limited, an electric insert or a new small gas fireplace may be the better option.
Will a small fireplace insert heat a room?
Yes. A properly sized gas, pellet, or wood insert can heat a room effectively, especially with a blower. Electric inserts provide supplemental heat.