Homeowners love the convenience and the versatility of a gas fireplace. But what about when an ice storm, heavy snow, high winds, or an equipment failure causes an electrical power outage? My forced air furnace will not operate without electricity. But can I use my gas fireplace when the power is out?
THE QUICK ANSWER
The answer to that question is “yes.” Many fireplaces will operate during a power outage, but it depends on whether your fireplace has:
- a standing pilot.
- Intermittent Pilot Ignition (IPI).
- battery back-up.
- and whether you want to use your blower fan.
If your fireplace has a battery back-up or a standing pilot, you’ll still get radiant heat off the front of the unit, even when the power is out. Fans won’t work during a power outage since they rely on house current for their power.
That being said, let’s get a little better understanding of how your gas fireplace works.
HOW DOES YOUR GAS FIREPLACE START?
When you flip a wall switch, click your remote, or your thermostat calls for heat, the gas valve on your fireplace will open. Gas valves generate their own electricity and operate on millivolts, a very small amount of electricity. That’s substantially less than the 120 volts that are needed for most household appliances, chargers, and lamps that plug into a wall outlet in your home.
PILOT LIGHTS AND MILLIVOLTS
Millivolts of electricity for your gas fireplace are generated by a small device called a thermocouple. Basically, a thermocouple is a sensor that measures temperature. It’s made with two different types of metals. Several of these thermocouples connected together are called a thermopile. A thermopile is about the diameter of a pencil and a couple of inches long. A small wire connects the thermopile to the gas valve.
A pilot light, or a very small gas flame about ¾” high, heats one end of the thermopile. Since one end is hotter than the other, the difference produces a temperature-dependent voltage. That voltage is millivolts of electricity whose purpose is to open and close the gas valve. It’s worth noting here that the normal position of a gas valve is closed. Without millivolts of electricity being generated, the gas valve cannot open and will remain in the closed position.
A pilot light has two primary functions. One is to generate millivolts in order to open and close the gas valve. Once the valve is open, the second function of the pilot flame is to ignite the fuel as it flows into the burner assembly.
TWO TYPES OF IGNITION SYSTEMS
For many years, standing pilot lights were kept burning 24/7/365 in fireplaces, water heaters, and furnaces. This type of technology has been around for decades and has been proven to be extremely reliable and consistent in its performance. However, since the pilot is always lit, this use of gas is considered wasteful by some. As a result, electronic ignition was developed.
An electronic ignition system does not utilize a standing pilot light. The pilot is on only when the fireplace (or furnace or water heater) is operational. After flipping a wall switch or pressing a remote control to start your fireplace, an on-demand electric source creates a spark and ignites the pilot light. This type of ignition system is called IPI, or Intermittent Pilot Ignition.
WHICH TYPE OF IGNITION SYSTEM IS BETTER?
Either type of system, millivolt or IPI, will start your fireplace. In the event of a power outage, the millivolt system will operate normally. The IPI system will operate normally provided the fireplace has battery back-up.
PROS AND CONS OF EACH SYSTEM
A millivolt system is a proven technology that’s time-tested and very reliable. It’s a simpler method to ignite the fireplace.
There are a couple of distinct advantages to keeping a pilot light on year-round. If you live in a damp or humid climate, there’s a very small amount of heat generated by a standing pilot light. This can keep the inside firebox dry and prevent rust from developing. A standing pilot light will also prevent small, silky spider webs from forming inside small orifices in the fireplace. Without that small amount of heat, those webs can form in the orifices — which usually means a service call to get the fireplace operational again.
An IPI system is going to be more “efficient” since natural or LP gas is used only when you flip a wall switch or click on your remote. However, IPI is a more complicated ignition system. It requires an electric source to create a spark that ignites the pilot light. If the power is out, the fireplace will not ignite on its own. But most IPI ignition systems for gas fireplaces will use a battery-powered backup module for starting the unit when power to the house is disrupted. Just make sure the batteries are fresh!
Many new fireplaces today use the IPI or electronic ignition system with an integrated battery back-up. The exact operation can vary by manufacturer and model. It’s always a good idea to read and understand your Owner’s Manual.
COMMON QUESTIONS AND CONSIDERATIONS
Today, many fireplace manufacturers produce units in both millivolt models and IPI models. There are some states where IPI technology is mandatory. Other states will allow either type of ignition.
1. How do I re-light a pilot light?
Re-lighting a pilot light on a millivolt system is fairly simple. The procedure is outlined in your Owner’s Manual and is also explained on an aluminum tag behind the bottom grill of your fireplace. If you want to see the procedure done, Napoleon Fireplaces has a good tutorial on the subject. Your fireplace may vary slightly from this alternate walkthrough, but if yours is a millivolt system, the procedure is essentially the same.
2. My fireplace has no vent pipe. Can a vent-free fireplace operate during an outage?
Yes, these typically have an IPI system. Just make sure the batteries are good.
3. What about the costs?
A fireplace with a standing pilot ignition system is typically a bit less expensive than a model with an IPI system. IPI uses newer technology and can be more difficult to troubleshoot than a standard millivolt system in a fireplace.
A personal side note: many We Love Fire dealers and their service techs would tell you that they prefer a millivolt system over an IPI system in a fireplace. Remember the old adage, “keep it simple, make it work”? That’s certainly appropriate here. There’s a lot less to go wrong in a millivolt system.
4. What if my remote doesn’t work?
Make sure there are fresh batteries in the remote and check the troubleshooting guide in the Owner’s Manual.
5. How do I change the batteries?
The location of the battery pack and access to it will be clearly defined in the Owner’s Manual.
6. How much does a pilot light cost to operate?
The cost to operate the pilot light on a millivolt system is approximately 4.5 therms (450,000 BTUs) of natural gas or about 5 gallons of LP gas per month. Gas rates can vary a lot depending on the time of year and by region. As this article was written, in the Midwest, gas usage for the pilot light on a millivolt system is approximately $4.50–$6.50/month for natural gas and about $5.25–$7.25/month for LP.
7. What about heating during a power outage?
Either type of ignition system will operate in the event of a power failure. Depending on the size of the gas burner, a substantial amount of radiant heat can be generated from the fireplace. This radiant heat from the appliance will warm the objects in the room.
However, no convective heat from the fan will be felt because it relies on house current. If the power is out to the house, regardless of the type of ignition system on your fireplace, the fan will not operate.
WHAT CAN BE DONE NOW?
It would be a good time to familiarize yourself with your fireplace and its operation. At the very least you should be prepared to:
- Replace batteries every fall.
- Test the fireplace and remote control function.
- Know where the battery pack is located.
- Schedule an annual service call.
KEY SUMMARY POINTS
- Most fireplaces will still work during power outages.
- Blower fans will not operate during an outage.
- Radiant heat will continue even without the blower fan running.
- Standing pilot lights do not need household electricity.
- Most IPI ignition fireplaces will have a battery back-up system to ignite the pilot light.
