Many homeowners love the idea of gas logs — until they realize the real question isn’t which ones look best…
It’s whether they will safely work in the fireplace at all.
Not every fireplace can accept every type of gas log set. The venting, firebox design, fuel type, and controls all determine compatibility before you ever pick a style.
This quick checklist will help you figure out what your fireplace can actually use — so you shop confidently and avoid costly mistakes.
What You’ll Know After This
By the end of this page you’ll know:
- Which type of gas logs your fireplace allows
- Whether you need vented or vent-free
- What fuel type you must use
- Which control systems are compatible
- What measurements you need before you buy
These are the same checks our technicians walk customers through before recommending a gas log set.
1) What Type of Fireplace Do You Have?
Your fireplace decides what will work — not the log style you like.
Most ordering mistakes happen when someone chooses a log set first… and checks compatibility later.
There are four common fireplace categories:
- Masonry fireplace (brick or stone)
- Prefabricated / zero-clearance fireplace (metal firebox)
- Vent-free firebox (made only for vent-free gas logs)
- Direct-vent fireplace (sealed glass-front system)
If you are converting a wood-burning fireplace
A traditional wood-burning fireplace is usually either masonry or prefabricated.
Masonry fireplace: typically built from brick or stone.
Prefabricated / zero-clearance fireplace: a metal firebox with imitation brick or porcelain liners. They can look like masonry fireplaces, but if you look inside, you’ll often find a “knockout hole” (a gas-line access hole) on one side.
Important: If you are installing gas logs in a prefabricated / zero-clearance fireplace, check the owner’s manual to confirm which gas log sets are approved for that specific firebox. If you’re unsure, contact the fireplace manufacturer with your model information (often stamped near the opening or behind the mesh screen).
If you have a vent-free firebox
A vent-free firebox is designed for vent-free gas logs only.
You cannot install vented gas logs in a vent-free firebox.
If you have a direct-vent fireplace (this matters a lot)
A direct-vent fireplace is a sealed system, usually with fixed glass and a dedicated vent pipe. These fireplaces are designed to use the manufacturer’s specific burner/log system.
You typically cannot remove the original direct-vent logs and replace them with vent-free or vented gas logs. This is one of the most expensive mistakes we see — because it often means the wrong product is purchased (or the original parts are thrown out) before someone learns it won’t work.
If you have a direct-vent unit and want a different look, the safest move is to check your owner’s manual and confirm what your manufacturer allows.
Service tip: If you’re converting a wood-burning fireplace, consider having your chimney swept and inspected before installing gas logs.
Service tip: If your fireplace already came with gas logs, check whether the manufacturer allows the log set to be changed. Some can and some cannot.
Safety note: Always install gas logs that are approved for your fireplace type and follow the manufacturer’s instructions. If you’re unsure, ask before you buy.
Not Sure Which Fireplace You Have?
You don’t have to guess — and guessing is how most ordering mistakes happen.
Take a quick photo of your fireplace and we’ll identify it for you before you buy.
- We’ll confirm the fireplace type
- Tell you which gas logs will work
- Help you avoid buying the wrong system
2) Does Your Home Use Natural Gas or Propane?
Gas logs are built for one specific fuel type and cannot use the other unless the burner is converted using approved parts (and many systems are not convertible).
You have two fuel options: natural gas or propane.
- If your home has a gas meter connected to a utility line → choose natural gas logs
- If your home uses a tank → choose propane logs
Some homes do not have a gas utility line available. In those cases, homeowners typically install a propane tank and use propane gas logs.
Important: Natural gas and propane burners are calibrated differently. Using the wrong fuel type can cause improper combustion and unsafe operation.
3) Do You Need Heat or Just the Look of a Fire?
This is where the venting decision becomes clear.
Quick rule: Vented gas logs = realism. Vent-free gas logs = heat.
Vented Gas Logs (Ambiance)
Vented gas logs create tall, natural-looking flames that burn around the logs and closely resemble a traditional wood fire.
They must be installed in a fireplace that vents fully to the outside through a chimney or approved venting system.
- Most realistic flame appearance
- Designed primarily for ambiance
- Chimney damper remains open during operation
Vent-Free Gas Logs (Supplemental Heat)
Vent-free (also called ventless or unvented) gas logs burn efficiently inside the firebox and release usable warmth into the room instead of sending heat up the chimney.
- Higher heat output
- Shorter, more controlled flames
- Used where allowed by local codes
Because the flames do not wrap around the logs the same way, vent-free logs may look less like a traditional wood fire — but they produce significantly more heat.
Good candidates for vent-free logs:
- Fireplaces that cannot vent properly
- Cold rooms or basements
- Long daily burn times
Ventilation note: Vent-free gas logs use room air for combustion. Cracking a window slightly can help maintain fresh air circulation during extended operation.
Code note: Some regions restrict vent-free gas logs regardless of fireplace type. Always verify local regulations before purchasing.
4) Should the Pilot Stay On or Turn Off?
Both systems are safe — the choice mainly comes down to convenience versus energy savings.
Quick difference: Standing pilot = always lit and very reliable. Intermittent pilot = turns fully off between uses.
Standing Pilot
The pilot flame stays lit even when the fireplace is off. When you turn the fireplace on, the main burner ignites immediately.
- Simpler operation
- Very reliable ignition
- Helps reduce insects or debris entering the burner ports
Intermittent Pilot (Electronic Ignition)
The pilot turns off completely when the fireplace is off and relights automatically when you activate the system.
- No constant pilot flame
- Slightly more efficient
- Common in newer installations
Neither system is better for everyone — choose based on whether you prefer always-ready operation or a fully off system between uses.
5) How Do You Want to Turn the Fireplace On?
Controls can be confusing — and they also impact price more than many homeowners expect.
You are not just choosing a handheld remote — you are choosing how the fireplace operates every day.
Choose the lowest control level you’ll be happy living with daily. Upgrades later are often limited.
Manual Control
You operate the fireplace directly at the unit using the control knob.
- Most affordable option
- No remote compatibility
- Requires bending down to operate
On/Off Remote Control
Turn the fireplace on or off from a handheld remote.
- Convenient everyday use
- No flame height adjustment
Variable Flame Remote
Adjust flame height up or down using the remote.
- More control over flame appearance
- Often requires specific valve systems
Thermostat Remote (Vent-Free Only)
Set a temperature and the fireplace cycles on and off automatically.
- Maintains room temperature
- Most automated operation
Different burners support different control options, so compatibility depends on the valve system included with the log set.
6) What Size Fireplace Opening Do You Have?
Rule: Gas logs must be smaller than the fireplace opening to allow proper airflow and prevent overheating.
A log set that is too large will not burn correctly and can damage the burner or controls.
You will need four measurements from the inside of your fireplace:
- Front width
- Back width
- Depth
- Opening height
Always use the inside dimensions of the firebox — not the outside surround or trim.
Tip: Leave space around the log set so air can circulate properly inside the fireplace.
7) Is Your Fireplace Single-Sided or See-Through?
Your fireplace opening(s) determine which log layout will look correct and burn properly.
Single-Sided Fireplace
This is the most common setup — one opening in the front. Most standard gas log sets are designed for single-sided fireplaces.
See-Through / Multi-Sided Fireplace
Some fireplaces have openings on two or three sides. These are often placed between rooms (for example, between a living room and dining room).
For these fireplaces, you’ll want a see-through gas log set designed to look finished from multiple viewing angles.
Tip: When shopping, look specifically for log sets labeled “see-through” or “multi-sided” for this style of fireplace.
Check Local Code Requirements
Building codes can affect which gas logs you are allowed to install.
Some areas restrict vent-free gas logs regardless of fireplace type, while others require specific safety controls. Always verify your local regulations before purchasing.
If you’re unsure, your city or municipality building department can confirm what is allowed in your area.
Still Not Sure? We’ll Check It For You
Tell us:
- Your fireplace type
- Your fuel type (natural gas or propane)
- A photo if possible
We’ll confirm compatibility before you order — so you buy once and buy correctly.
Reach out to an American Gas Works gas log expert via our online chat, email us at customersupport@americangasworks.net, or call us at 866-757-5344.