Millivolt vs Electronic Ignition Gas Fireplaces: What's the Difference?
Every gas fireplace needs a pilot flame to light the burner and a way to open the gas valve. Millivolt and electronic ignition handle both jobs in different ways, and you'll notice the difference on your gas bill, during a power outage and in where the fireplace is allowed to go.
A millivolt fireplace keeps a pilot burning around the clock and makes its own electricity from that flame. An electronic ignition fireplace, often called IPI for intermittent pilot ignition, sparks a pilot only when you turn the fireplace on. Several fireplaces we carry come both ways at the same size and output, so the choice is often yours. Every figure below comes from the manufacturers' installation manuals, our own product pages or published government sources.
The difference in one paragraph
Choose millivolt if you want a fireplace that lights with the power out and has the fewest electronic parts. The trade-off is a pilot flame that burns gas whenever the valve is on. Choose electronic ignition if you want the pilot off when the fireplace is off, less gas burned between fires, and a continuous pilot only on the days it helps. Electronic models need a 120V outlet or a plug-in adapter, and they run on backup batteries in an outage. In California and Canada, the rules point you to electronic ignition.
Millivolt vs electronic ignition at a glance
| Millivolt (standing pilot) | Electronic ignition (IPI) | |
|---|---|---|
| How the pilot lights | Once, by hand, with a push-button piezo igniter | Automatically, with a spark each time the fireplace turns on |
| Pilot while the fireplace is off | Stays lit until you turn the gas valve off | Goes out, unless you switch it to continuous pilot mode |
| House power | Not needed to run the burner | 120V supply or a plug-in AC adapter |
| Power outage | Lights and runs as usual | Lights and runs on backup batteries (four AA on the Superior and Empire models) |
| Blower during an outage | No | No |
| Gas burned between fires | A steady pilot flame, about 1,000 Btu an hour by the Department of Energy's estimate | None in intermittent mode |
| Cold-weather starts | The pilot keeps the flue and glass warm | Can fog the glass or cycle on startup in extreme cold; the continuous pilot setting fixes it |
| Parts that wear | Thermopile and thermocouple | Igniter, flame sensor, control module and backup batteries |
| Restricted in | California and Canada (details below) | No pilot restrictions |
How a millivolt fireplace works
A millivolt fireplace has a standing pilot: a small flame next to the main burner that stays lit whenever the gas valve is set to on. You light it once, by turning the valve knob to PILOT, pushing it in and pressing the piezo igniter button until the pilot catches. Superior's DRT2000 manual says to keep holding the knob in for about 1-1/2 minutes after the pilot lights.
Two sensors sit in that pilot flame. A thermocouple proves the pilot is lit and holds the safety valve open, so the gas shuts off if the pilot goes out. A thermopile turns the pilot's heat into a small electric current, a fraction of a volt, and that current opens the valve to the main burner when you flip the switch. Empire calls its version a 750 millivolt system, and its manual says the thermopile is self-generating and the gas valve needs neither 24 volts nor 110 volts.
That self-made power is the appeal. The fireplace lights and runs in a power outage, and there is no circuit board to fail. Two things to plan for:
- A switch is required. Superior ships its millivolt DRT2000 models without factory-installed controls, so you add a wall switch, unit-mounted switch, thermostat or remote. Superior also warns never to connect a millivolt wall switch to 120V power.
- The pilot burns until you turn it off. Empire's manual says to leave the valve on during the heating season and turn it to OFF when the season ends, which shuts down the pilot.
When a millivolt fireplace won't come on, a weak thermopile is a common cause. Superior's troubleshooting chart calls for at least 325 millivolts at the valve with the wall switch off, and Empire's Tahoe manual calls for at least 350.
How electronic ignition works
An electronic ignition fireplace has no flame at all while it's off. When you turn it on with the switch, remote or thermostat, the control sends a spark to the pilot. A sensor confirms the pilot is lit, and the valve then opens to the main burner. Empire's manual puts the wait at a few seconds while the pilot sensor heats up. Turn the fireplace off and the burner and pilot both go out.
The electronics need power. Superior's electronic models are wired to a 120V supply, and Empire's intermittent pilot models run on an AC adapter that comes with the fireplace. Both brands include a battery holder for four AA batteries that takes over in an outage, and Superior says to install new batteries before every burn season.
IPI and CPI: the continuous pilot switch
Most of the electronic systems we carry have an IPI/CPI switch. IPI, intermittent pilot, lights the pilot only while the fireplace runs. CPI, continuous pilot, keeps the pilot lit after the burner shuts off, the way a standing pilot does.
A continuous pilot has its uses. Superior's manual says that in extreme cold the glass can fog while the pilot is off. The fireplace may also cycle on startup, lighting and going out a few times until the flue is warm enough to draft. Keeping the pilot lit prevents both. Empire recommends leaving its intermittent pilot fireplaces in continuous mode during the heating season to reduce cold-start problems, and during a power outage to save battery power.
Napoleon adds a timer to the same idea. It says all of its electronic ignition fireplaces made since January 2020 use a pilot-on-demand system: in continuous mode, the pilot shuts itself off after about seven days without use.
How much gas a standing pilot burns
A pilot flame is small, but it burns every hour the valve is on. When the U.S. Department of Energy studied decorative gas fireplaces and log sets in a 2022 proposed determination, it used 1,000 Btu per hour to represent a standing pilot. At that rate:
| Pilot left on for | Natural gas | Propane |
|---|---|---|
| One day | 0.24 therm | About 0.26 gallon |
| One month | 7.2 therms | About 7.9 gallons |
| A six-month heating season | About 44 therms | About 48 gallons |
| A full year | About 88 therms | About 96 gallons |
Multiply by your own gas or propane rate to see what that means for your bill. The conversions use the U.S. Energy Information Administration's figures of 100,000 Btu per therm and 91,452 Btu per gallon of propane. Your pilot may burn more or less than DOE's 1,000 Btu figure.
For a fireplace you run mostly for looks, the pilot can outburn the fire. In the same study, DOE found that 71 percent of fireplaces and log sets used a standing pilot. It estimated that the average decorative fireplace used 2.7 million Btu a year on ignition and 1.5 million Btu in its main burner. A fireplace you heat with every evening burns far more gas in the burner, so for you the pilot is a smaller share of the total.
The efficiency ratings show it too
Superior sells its DRT2000 fireplace with either ignition at the same input ratings, and the manual lists both versions on the Canadian annual fireplace efficiency test (CSA P.4.1). The electronic versions score 1 to 4 points higher on every size and fuel:
| DRT2000 size | Millivolt, natural gas | Electronic, natural gas | Millivolt, propane | Electronic, propane |
|---|---|---|---|---|
| 35" | 59.1% | 62.7% | 59.8% | 62.6% |
| 40" | 59.4% | 61.7% | 59.2% | 63.5% |
| 45" | 57.3% | 61.3% | 61.5% | 62.8% |
Superior notes that the electronic units were rated with the continuous pilot turned off.
What happens in a power outage
Both kinds keep working. A millivolt fireplace makes its own power, so it lights and runs as usual. An electronic fireplace switches to its backup batteries. Superior's manual says to turn the switch or remote on as usual, and the unit should spark and light; if there's no spark, replace the batteries.
Neither one will run its blower. Blowers need 120V, so during an outage you get the radiant heat through the glass and nothing more. Superior's manual is specific that the battery backup runs the fireplace but not the blower. If outages are common where you live, the batteries matter: a millivolt fireplace has nothing to replace, while an electronic one depends on the AA cells in its battery holder.
Where standing pilots aren't allowed
- California. Section 110.5(e) of the California Energy Code allows indoor and outdoor fireplaces to be installed only if they do not have a continuously burning pilot light. In California, plan on electronic ignition.
- Canada. Under Canada's Energy Efficiency Regulations, gas fireplaces made on or after January 1, 2020 must put the pilot out automatically when the burner goes out. A fireplace that can be switched to a continuous pilot has to keep it from burning more than seven days. Napoleon ties its seven-day pilot timer to this rule.
- The rest of the U.S. There is no federal ban. DOE had moved toward energy standards for decorative fireplaces and gas logs, then withdrew that determination in May 2025. Local codes can still apply, so check with your building department.
Fireplaces we carry in both versions
The fireplaces below come in a millivolt and an electronic version. Pick the ignition when you order. Superior lists different gas valves and pilot assemblies for the two versions, and Empire sells separate fuel conversion kits for its millivolt and intermittent pilot models, so plan on keeping the ignition you buy.
Superior DRT2000 and DRT3000
The Superior DRT2035, DRT2040 and DRT2045 are mid-size direct vent fireplaces, 17" deep, offered with millivolt or electronic ignition. The electronic versions come with the IPI/CPI switch and battery backup as standard. The DRT3040 and DRT3045 come both ways too.
Empire Tahoe, Loft, Boulevard, Spirit and Innsbrook
Empire offers most of its gas line in millivolt or intermittent pilot. On the Tahoe Deluxe 36, Tahoe Premium 36 and Tahoe Luxury 36, the millivolt models run the burner without house power, and the intermittent pilot models use an AC adapter with battery backup. The Premium and Luxury also come in a multi-function version with a remote for flame height and blower speed, plus the accent lamp on the Luxury. Our Tahoe Deluxe vs Premium vs Luxury guide compares the three.
You get the same choice on the Loft 36 linear fireplace and the vent-free Boulevard 36, which pairs millivolt with an on/off remote and intermittent pilot with a thermostat remote. It also applies to the Spirit cast iron stoves, where a switch on the intermittent pilot models selects intermittent or continuous pilot, and to the Innsbrook direct vent inserts.
Napoleon Havelock and Arlington stoves
The Napoleon Havelock and Napoleon Arlington direct vent stoves come with electronic or millivolt ignition. The millivolt versions need no electricity to run, and the electronic versions have a battery backup for power failures.
So which one
Start with how often you'll use the fireplace and how often the power goes out.
- The power goes out often, or the fireplace is your backup heat: millivolt. It lights with no power and no batteries. In an outage, either type gives radiant heat only.
- You'll light it a few times a week or less: electronic ignition. Otherwise the pilot burns gas all week for a couple of evenings of fire.
- You'll run it every evening all winter: either works. The pilot is a small share of the gas you burn, and the CPI setting on an electronic model gives you a standing pilot during the coldest weeks.
- A cabin or second home: electronic ignition, so nothing burns while you're away. If outages are common there, keep fresh batteries in the battery holder.
- California or Canada: electronic ignition, for the reasons above.
- You want flame height and blower speed on the remote: the multi-function Empire Tahoe Premium or Tahoe Luxury.
Not sure which version fits your home? Call us at 888-486-2909, tell us how you plan to use the fireplace and how often your power goes out, and we will help you choose. We are here Monday to Saturday 9am to 9pm and Sunday 9am to 6pm CST. You can also browse all of our direct vent gas fireplaces, gas fireplace inserts and direct vent gas stoves, or read our direct vent explainer.
Frequently asked questions
What is the difference between millivolt and electronic ignition?
A millivolt fireplace keeps a standing pilot lit and powers its gas valve from the pilot's heat, so it needs no electricity. An electronic ignition fireplace sparks the pilot only when you turn it on, which saves gas between fires, but it needs house power or its backup batteries.
Does a millivolt fireplace need electricity?
Not to light or run the burner. You need an outlet only for a blower or other powered accessories.
Will an electronic ignition fireplace work in a power outage?
Yes, if its backup batteries are good. The Superior and Empire models we carry take four AA batteries for this. The blower won't run on batteries.
How do I know if my gas fireplace is millivolt?
Open the control compartment. A millivolt valve has a knob marked OFF, PILOT and ON and a push-button piezo igniter, and its pilot stays lit while the fireplace is off. An electronic fireplace shows no pilot flame while it's off, sparks when you turn it on, and has a power cord or adapter and a battery holder.
How many millivolts should a fireplace thermopile put out?
Check your manual, because each valve has its own number. Superior's DRT2000 calls for at least 325 millivolts at the valve with the wall switch off, and Empire's Tahoe manual calls for at least 350.
What are the downsides of electronic ignition?
It needs a 120V outlet or adapter, backup batteries that should be replaced every season, and more electronic parts. In extreme cold, intermittent mode can fog the glass or make the fireplace cycle on startup until the flue warms up, which the continuous pilot setting fixes.
Can I convert a millivolt fireplace to electronic ignition?
Plan on keeping the ignition you buy. On the Superior DRT2000, the two versions use different gas valves and pilot assemblies. If you think you might want to switch later, call us about the specific model before you order.
Should I turn off a millivolt pilot in the summer?
Turning it off saves gas. Empire's manual says to turn the valve to OFF when the heating season ends, and Natural Resources Canada says turning off the pilot during periods of little or no use can save energy. Relight it in the fall by following the lighting instructions in your manual.