Should You Turn Off the Gas Fireplace Pilot in Summer?

What a standing pilot does all summer

A standing pilot is a small flame that burns whenever the gas valve is in the pilot or on position, ready to light the main burner when you flip the switch. Next to it sits a thermocouple or thermopile, a sensor that the pilot flame keeps hot. As long as it stays hot, the valve stays open; if the pilot goes out, the sensor cools and the valve shuts off the gas. That is the safety logic of a standing-pilot system.

The flame itself uses a modest amount of gas, but it runs every hour of every day. Over a summer with the fireplace unused, that adds up, and the little flame also puts warmth into a room you are paying to keep cool. If you will not use the fireplace from spring to fall, there is little reason to keep a flame going inside it.

Why some people leave it on

The pilot keeps the firebox slightly warm, which can help keep moisture from settling on the burner, the valve and the glass in a damp room or a humid summer. That matters more in basement family rooms and in homes near the shore, where summer humidity is high. A unit left cold for months can also collect dust, lint and spider webs around the burner ports and pilot tube, which can make the pilot hard to light or cause a lazy, yellow flame in the fall.

Relighting is the other factor. On many fireplaces it takes a minute. On some it means removing a lower panel, holding a knob in and pressing an igniter repeatedly until the pilot catches, then holding the knob for a set time. If you are not comfortable with that, or the instructions are missing, leaving the pilot on or having a technician relight it in fall are both reasonable choices.

Off or on: weighing it up

Neither choice is wrong. These are the trade-offs most owners weigh.

• Gas use: none with the pilot off; a small but constant amount with it on
• Room heat: none added with it off; some warmth all summer with it on
• Moisture: parts sit cold and may get damp with it off; the firebox stays slightly warm with it on
• Insects and dust: more likely to collect with it off, less likely near a burning pilot
• Fall start-up: relight by the manual if it was off; ready to go if it stayed on

How to turn it off properly

The steps differ between models, so the manual or the lighting label on the unit is the guide to follow. That label is usually on the back of the lower access panel or attached near the valve by a chain. In general, the sequence looks like this:

• Turn the fireplace off at the switch, thermostat or remote and let it cool
• Find the control valve, often behind a lower access panel
• Turn the control knob from PILOT to OFF, as the label shows
• Leave the main gas shutoff valve as the manual directs
• Put the manual or a photo of the label somewhere you will find it in fall

Electronic ignition units

Many gas fireplaces made in recent years use intermittent pilot ignition. The pilot only lights when you turn the fireplace on and goes out when you turn it off, so it uses no gas while idle. These units usually need power, either house current or batteries in a receiver, and a dead battery is a common reason they will not light in fall.

Some of these models have a setting that keeps the pilot running in cold weather to keep the glass and the vent warm, which helps the unit start cleanly and reduces condensation. The manual explains when to use each mode. If you are not sure which kind you have, the model number on the rating plate will tell you, and a pilot flame visible behind the glass with the fireplace off means it is a standing pilot.

Gas logs in a masonry fireplace

Gas log sets installed in a brick fireplace work a little differently from a sealed gas fireplace. Many have a standing pilot sitting in the open firebox, and vented log sets need a chimney flue that stays open while they run. In installations where the damper is clamped open so it cannot be shut by mistake, conditioned air and humid summer air move through the flue all season whether the pilot is on or off.

For those setups, the summer question often becomes a chimney question as well. A cap keeps rain and animals out of the open flue, and the yearly sweep and inspection catch soot from logs that have shifted out of position. If the pilot in an open firebox keeps blowing out on windy days, the draft and the cap are worth checking along with the pilot assembly.

A vent-free log set is a separate case, with its own manual, its own oxygen-sensing pilot and no chimney involved in its venting. Follow its instructions for seasonal shutdown.

Relighting in the fall

Follow the lighting label exactly. Most labels tell you to turn the valve to OFF and wait several minutes before relighting, so any gas from an earlier attempt clears. If the pilot will not stay lit after you release the knob, the thermocouple or thermopile may be weak or the pilot flame may not be reaching it; repeated attempts will not fix that.

A pilot that lights but burns small, yellow or wavering often has dust or a spider web in the pilot tube or orifice. That is a cleaning job for a gas fireplace technician, not something to probe with wire.

Before the first cold night

Months of sitting idle are a good reason to have the fireplace and its vent looked at before heating season. Insects, nests and leaves can block the vent termination outside, and dust on the burner and logs can change the flame. NFPA 211 puts gas vents on the same yearly inspection schedule as wood-burning chimneys, and the visit usually covers the burner, pilot assembly, log placement, glass gasket and the vent from the unit to the termination.

If you smell gas at any point, whether near the fireplace or anywhere in the house, do not try to light anything or operate switches. Leave, and phone 911 or the utility company from outside. Make sure the carbon monoxide alarms near the fireplace and the bedrooms are working before the heating season starts.