If you’re considering purchasing a Valor gas fireplace or another high-quality option from Croft Fireplace, you might be wondering how much gas is needed to operate it. How much gas does a gas fireplace use? It’s a crucial question for estimating your fuel costs.

A gas-burning fireplace requires a constant gas source to function, which involves a different cost calculation than other types of fireplaces. However, the amount of gas you need varies greatly depending on a number of considerations. 

We’ll explain gas fireplace BTU, break down the factors that impact how much a gas fireplace costs to run, and share some cost-saving tips to help you enjoy the glow and heat without breaking the bank.

Browse a specific category by clicking on any of the quick links below:

• Understanding Your Fireplace’s BTU
• Factors That Impact the Cost of Gas for Your Gas Fireplace
• How to Calculate Fuel Costs
• Cost-Saving Tips for Using Gas Fireplaces
• Reach Out to Croft Fireplace for Help

Understanding Your Fireplace’s BTU

Before you make any calculations, it’s important to understand BTU. Short for British thermal unit, BTU is a measurement of heat that indicates how much heat a fireplace creates with the maximum amount of fuel. Knowing the BTU of your gas-burning fireplace will help you calculate the cost of using it. 

For example, a fireplace with a 60,000 BTU rating will consume up to 60,000 BTUs per hour of use. However, the level of BTU varies based on different circumstances.

Consult your fireplace provider to learn more about your fireplace’s BTU. This information is essential for estimating fuel costs.

Factors That Impact the Cost of Gas for Your Gas Fireplace

Quite a few components come into play to influence the amount you’ll pay to use your gas fireplace. Here are some of the factors that make a difference.

Fuel Source

The cost to use a gas-burning fireplace varies based on whether it’s fueled by natural gas or propane. These fuel sources cost different amounts per therm, a measurement of how much fuel is needed per 100,000 BTU. 

Natural gas is typically sold by the therm (100,000 BTUs), while propane is sold by the gallon (which equates to about 91,500 BTUs). Though the units differ, propane often costs more per BTU. If natural gas costs $1.20 per therm and propane costs $3.00 per gallon, for example, propane heating ends up being significantly more expensive for the same heat output. 

Staying apprised of the current rates of natural gas vs. propane costs is essential for estimating overall heating prices accurately.

Fireplace Purpose

One aspect that can influence how much BTU a gas-powered fireplace has is whether it is designed to be a decoration or a heat source. Decorative fireplaces are intended to benefit a room’s ambiance and appearance, whereas heat-producing ones are meant to warm the entire room. You can actually get the most bang for your buck with an energy-efficient direct vent fireplace—it produces significantly more heat and uses much less fuel than an open gas-log fireplace.

Usage Details

Another factor determining how much your gas-powered fireplace will cost is the time of year in which you intend to use it. Gas is only used when your fireplace is running, so you’ll pay more the longer the unit runs. You may choose to run the fireplace more in the winter when it’s colder, using more fuel. In the summer, you may decide not to turn it on at all. Factoring in how many hours, days, and times of year you will be operating the fireplace is essential when making your final calculations.

Fireplace Settings

How often you use your fireplace has a big impact, but so do the settings you select when you turn it on. It won’t come as a surprise that intense, bigger flame setups will use more fuel than more modest settings. Adjusting your gas fireplace to produce large flames, cranking the temperature, and using the unit more often will all increase your fuel costs.

Maintenance Regularity

You probably know that you’re likely to save money at the gas pump if you get regular oil changes, keep your tires evenly inflated to the correct PSI, and follow the manufacturer-recommended maintenance schedule for your car. Gas fireplaces may not have tires, but they operate under a similar principle.

Hiring a professional for an annual check-up and regular maintenance services can keep your fireplace running at peak efficiency, saving money in fuel costs. On the flip side, a lack of maintenance can leave your fireplace working harder to achieve the results it once did—driving up fuel use and prices. Damaged vents, clogged ports, debris build-up, and reduced airflow all have an impact.

Climate

It’s common sense: Colder weather generally encourages us to use our fireplace. There’s nothing quite like snuggling up in front of a fireplace while the air is crisp and snow blankets the world outside. If you experience lengthy, extreme winters where you live, there’s a good chance you’ll need more gas. You’ll be using your fireplace more often and at a higher temperature.

But elevation also comes into play. Those living in the Utah mountains may experience reduced air density, which can drive up gas consumption. Being surrounded by majestic mountains is stunning, but this is one trade-off.

Fireplace Size

Bigger fireplaces cost more to maintain and use than smaller units. It’s really that simple. Now, as we pointed out earlier, settings also come into play. A large gas fireplace in lower settings may use less gas than a medium-sized fireplace that is always running full blast. But all other factors being equal, a big, beautiful fireplace simply costs more to run.

Home Style

Your home’s design and layout help determine how much gas you need to heat a room and keep everyone toasty. A ranch-style home with a relatively closed den or living room may do a better job of keeping the heat contained compared to a modern house with vaulted ceilings and an open floor plan. 

How to Calculate Fuel Costs

As you can probably tell from our long list of factors impacting total cost, there are many variables that make a simple calculation challenging. We can offer some generalizations, but you’ll have to look at your actual usage, along with the factors above, to get an accurate estimate.

You’ll need to know your gas fireplace’s BTU rating, whether you’re using propane or natural gas, and local fuel rates.

1. Figures depend on the value of a BTU per unit of fuel.
   • Natural Gas: 100,000 BTU per therm
   • Propane: approximately 91,500 BTU per gallon
2. Divide your fireplace’s BTU output by the BTUs per unit of fuel to see how many therms or gallons it uses per hour.
   • Example: Let’s look at a 30,000-BTU gas fireplace. With natural gas, it would use up to 0.3 therms per hour. With propane, it would use around 0.33 gallons per hour. If you’re running the fireplace on lower settings, it’s probably using fewer BTUs.
3. Multiply the answer by the current rate per unit of fuel to calculate the cost per hour.
   • Example: Continuing our example of the 30,000-BTU fireplace above, let’s say natural gas costs $1 per therm. The fireplace would cost about $0.30 per hour to operate at full capacity. If propane costs $2.66, then your propane-fueled gas fireplace would cost around $0.88 per hour to run.

Cost-Saving Tips for Using Gas Fireplaces

A gas fireplace epitomizes warmth, coziness, and comfort. We believe its value goes beyond the warmth it provides; it offers a homey yet luxurious experience. 

But very few of us get to live our lives without checking our bank account balances. Here are some money-saving tips to help you enjoy the experience while considering total costs.

Use Energy-Efficient Fireplace Inserts

Certain inserts are designed to offer more heat while using less energy. If your current setup isn’t designed for energy efficiency, upgrading to an eco-friendly fireplace insert can be a wise investment for the environment and your monthly fuel costs.

Install a Fireplace Blower

This special fan can make your gas fireplace more efficient by spreading the hot air out, helping the room heat more quickly and effectively. A fireplace blower may enable you to use lower settings for the same effect, reducing your BTU and overall energy consumption.

Invest in Proper Maintenance

We mentioned this above as a factor in your spending. If a lack of regular maintenance can drive up costs, you can save money on fuel by having a professional look at your system and make sure it’s running at peak efficiency. Croft Fireplace offers gas fireplace maintenance; it’s a great place for Utah residents to start.

Saving on Overall Heating Costs

We’ve been focused on saving fuel costs for your gas fireplace, but what if you could actually utilize your fireplace to reduce your home heating bills? One of the best ways to reduce your gas bill during colder months is to practice zone heating. This involves keeping your thermostat at a cooler temperature and just heating the spaces where you spend the most time. 

If the idea sounds familiar, you’ve hit the nail on the head: Using a gas fireplace for heat is an example of zone heating in action! Turn your furnace down and spend more lazy nights reading or watching TV in front of the fire. An energy-efficient fireplace insert uses much less fuel than heating your entire house with your furnace. 

One customer reported reducing his gas bill by $50 per month by adding a single fireplace insert to his home! 

Reach Out to Croft Fireplace for Help

At Croft Fireplace, we have the expertise to take care of all your fireplace needs. We are the premier stop for Utah residents looking for a new fireplace. Our financing options make your new fireplace easy to pay for, too. 

We look forward to working with you to bring the beauty of a fireplace into your home.

Fireplaces have long been the heart of the home, but the way we interact with them is shifting. No longer just a utilitarian heat source tucked into a brick alcove, the modern fireplace has evolved into a sophisticated design element that defines the architecture of a room. If you are planning to add or convert to a gas fireplace this coming year, you are likely looking for gas fireplace ideas that blend cutting-edge technology with timeless aesthetics.

Introduction

In many cases, yes. You can add a thermostat to a gas fireplace as long as the fireplace and the thermostat are compatible. Thermostat control lets the fireplace respond to room temperature instead of waiting for you to switch it on and off.

Do gas fireplaces work with thermostats across the board? No. They use different control systems, and each accepts a different range of thermostats. Confirming compatibility first prevents damage to the controls.

Some units use a millivolt system, others low-voltage wiring or a control module, so requirements vary and some jobs call for a technician. If you are still shopping, a trusted fireplace store can point you toward models with thermostat control already built in.

Can You Add a Thermostat to a Gas Fireplace?

A thermostat can control many gas fireplaces, but not all of them. It opens and closes the circuit that tells the fireplace to light or shut down. If your unit accepts that signal, a compatible thermostat can run it.

Do gas fireplaces have thermostats built in? Many newer ones effectively do. Models like the Valor H6 and H3 include a handheld remote that acts as the thermostat, reading room temperature and cycling the fireplace with no wall device at all. Most older units rely on a plain switch instead. So can you put a thermostat on a gas fireplace you already own? It depends on the control system. Units with a simple on and off switch often accept a thermostat in its place. Fireplaces with sealed modules or proprietary receivers may only accept the brand’s accessory.

Your manufacturer’s specifications settle it. The installation manual and the rating plate behind the lower louver tell you what the unit accepts. When the manual is missing, a professional assessment is worth the call. The same applies during a new gas fireplace installation, where thermostat wiring is easier to plan beforehand.

How Does a Thermostat Work With a Gas Fireplace?

So how does a gas fireplace thermostat work? A compatible thermostat talks to the fireplace control system through a low-power circuit. It completes or breaks a connection, and the fireplace responds.

The thermostat reads the air temperature in the room where it sits. When the room drops below your set point, it closes the circuit and the fireplace ignites. Once the room warms to that setting, the circuit opens and the fireplace shuts down.

The gas valve does the actual work. It receives the signal, then manages ignition, flame, and shutdown by the manufacturer’s design. The thermostat only asks for heat.

Compare that with manual operation. With a plain wall switch, you decide every time the fireplace runs, so the room swings warm, then cool. Thermostat control smooths those swings out.

What Type of Thermostat Works With a Gas Fireplace?

The right thermostat depends on the control system inside your fireplace. Voltage, wiring, and manufacturer requirements decide the answer, not the features you prefer.

Millivolt thermostats are the most common match for older and standing-pilot fireplaces. A millivolt system makes its own power from a thermopile heated by the pilot flame, which is why these units still light during an outage. That power is tiny, so the thermostat must be rated for millivolt loads.

Low-voltage thermostats, typically 24 volts, suit fireplaces built around a transformer or control module, but only when the manufacturer lists that voltage and wiring as approved for your model.

Programmable thermostats add schedules, so the fireplace can warm a room before you wake up or shut down at bedtime. Compatibility is narrower, since many need battery or hardwired power a millivolt fireplace cannot supply.

Smart thermostats vary the most. Some manufacturers sell app-connected controls for their own fireplaces, and those work well. General purpose models often need a common wire or constant power a fireplace circuit does not provide.

One assumption causes most failed installations. A thermostat that runs your furnace is not automatically safe for your fireplace, and an HVAC model on a millivolt circuit can leave the unit unresponsive or damage the valve.

Thermostat Compatibility Comparison

This is a general comparison. Your manufacturer and model number determine what actually works.

How to Add a Thermostat to a Gas Fireplace

At a high level, this is a short project with one demanding step, confirming compatibility.

Start by identifying your fireplace model and control system. Look for the rating plate behind the lower louver or inside the access panel and note the make, model, and serial number. Then check the manufacturer’s specifications for which thermostats the unit accepts and at what voltage. A remote-controlled model may already have the feature built in.

Next, look at what is already on the wall. A basic switch, a remote receiver, or a control module each point to different options. Then choose one the manufacturer approves.

Installation generally means connecting the thermostat to the fireplace control circuit in place of the existing switch, following both sets of instructions exactly. Then test a full cycle, raising the set point to confirm ignition and lowering it to confirm a clean shutdown.

Wiring differs between models, and familiar terminal labels do not always carry the same function. If anything is unclear, bring in a technician. Our fireplace repair services cover thermostat and control work in Utah, and a service call costs less than a replaced valve.

Installation Considerations and Common Mistakes to Avoid

Gas fireplace thermostat compatibility comes first, followed by wiring, the millivolt or low-voltage nature of the system, and power needs. Placement, manufacturer requirements, and local safety rules round out the list.

Placement deserves more attention than it gets. A thermostat mounted too close reads heat coming off the fireplace rather than the room, so it shuts down early and leaves the rest of the space cold. Mount it on an interior wall, away from direct heat, drafts, and sunlight.

Wiring mistakes are the expensive kind. The wrong voltage in a millivolt circuit can damage the valve or control board, a repair costing more than the thermostat.

The common errors are worth naming plainly. Homeowners install an incompatible thermostat, assume any HVAC model will work, ignore manufacturer requirements, modify wiring blindly, choose a poor location, or skip testing. Each traces back to the same fix. Confirm compatibility before buying or connecting anything.

Benefits of a Thermostat-Controlled Gas Fireplace

The main benefit is a steadier room. Instead of running until someone notices the space is too warm, the fireplace cycles around your setting and holds it.

Automatic operation is the second benefit. The fireplace responds to the room on its own, so nobody has to track how long it has run or get up to turn it off. You set a number and leave it.

There can be efficiency gains too, since the fireplace runs only when the room calls for heat, though results depend on your home and habits. For anyone using a gas fireplace as supplemental heat, that cycling is where thermostat control earns its keep.

Can You Replace a Wall Switch With a Thermostat?

Often, yes. If a simple wall switch controls your fireplace and the manufacturer approves thermostat operation, a compatible thermostat can take that switch’s place on the same wires.

The wiring already in the wall shapes what is possible. Millivolt fireplaces usually run two thin wires to the switch, which suits a millivolt thermostat. Module or receiver based systems may need a manufacturer accessory.

The difference is straightforward. A wall switch is manual and holds the fireplace on until you flip it off. A thermostat cycles it automatically on room temperature.

An existing switch is not proof that any thermostat will work. It tells you the circuit is reachable, not that the fireplace accepts the device you have in mind. Confirm the control system first, and call a professional when compatibility is unclear.

Frequently Asked Questions

Does installing a thermostat on a gas fireplace require an electrician?

Not always. Millivolt systems use very low power and no household current, so a fireplace technician usually handles it. If line voltage or a new circuit is involved, call an electrician.

Will a smart thermostat work without external power on a millivolt system?

Usually not. Most smart thermostats need constant power a millivolt fireplace cannot supply. Look for a smart control designed by your manufacturer instead.

Is it safe to leave a gas fireplace on thermostat mode overnight?

Follow your manufacturer’s guidance. Many fireplaces are approved for thermostat operation, though some manuals advise against unattended overnight use. Working carbon monoxide and smoke detectors are essential.

Can I use a regular thermostat on a gas fireplace?

Only if it is rated for your fireplace’s system. Standard furnace thermostats are built for HVAC voltages and can fail to trigger a millivolt valve, or damage it.

How do I know if my gas fireplace is thermostat compatible?

Check the rating plate for the model number, then review the installation manual or manufacturer’s website. A technician can confirm it in one visit.

Can an existing gas fireplace be upgraded to thermostat control?

Many can, particularly millivolt units with a wall switch. Older or proprietary systems may need a manufacturer accessory. Newer remote-equipped models often need nothing at all.

Final Thoughts

Many compatible gas fireplaces can run on thermostat control, and the comfort gain is worth the effort. The rule that matters is confirming compatibility before you buy.

Control systems vary between brands and model years, so follow your manufacturer’s requirements and call a professional when wiring is unclear. Explore your options with Croft Fireplace and request a quote for expert guidance.

As the crisp autumn air begins to roll off the Wasatch Range and settle into the valleys of Salt Lake, Davis, and Weber counties, there is nothing quite like the flick of a switch that brings a warm, glowing hearth to life. Whether you are coming home from a day of skiing at Snowbird or just settling in for a cozy evening in Bountiful, your gas fireplace is the heart of your home’s comfort.

The fallout from climate change grows more noticeable with each passing year, which is why it makes sense to look for greener, more eco-friendly options in all aspects of your life, including your home. In honor of Earth Day, let’s run down some ways that you can celebrate planet Earth by going green at home and reducing your water and carbon footprints.