When a gas fireplace pilot won't stay lit

Before you touch the controls

Everything an owner should do is printed on the lighting instructions attached to the fireplace and in the owner's manual. This guide stays inside those limits. Taking apart the gas valve, loosening fittings, sanding or replacing sensors, adjusting gas pressure or bypassing any safety device is work for a qualified technician.

First, find out which ignition you have

The lighting label is usually near the controls, often behind a lower grille or access panel, along with the rating plate that lists the make and model. With the model number you can download the manual from the manufacturer's website. The label will tell you which of two broad designs you have.

Standing pilot

A small flame burns continuously while the fireplace is in service. You light it at a control knob marked OFF, PILOT and ON, using a push-button spark igniter or, on some older units, a match. Remotes and wall switches on these units turn the main burner on and off; they do not light the pilot.

Electronic ignition

There is no pilot to light by hand. The remote, wall switch or thermostat starts a sequence in which a spark lights the pilot and the control then opens the main burner. Regency's manual for its Gi27LE, for example, describes the system sparking for 60 seconds to light the pilot, pausing about 35 seconds if no flame is sensed, and going into lockout if it still fails. Some models can be set to keep the pilot lit continuously; the same manual notes that its on-demand pilot shuts itself off after seven days.

Why a pilot goes out on purpose

Every gas fireplace is built around one rule: gas flows only while the control can prove there is a flame to burn it. On a standing pilot system, the pilot flame heats a thermocouple, which Napoleon describes as the sensor that detects heat and keeps the pilot lit. A larger version, the thermopile, generates the power that lets gas reach the main burner. Regency's owner guidance puts the safety side plainly: if the pilot flame goes out, the valve shuts down and the fireplace turns off.

Electronic systems use a flame sensor near the pilot for the same purpose. If the sensor does not report a flame, the board stops and eventually locks out.

So the useful question is what is keeping the control from proving the flame. The answer can be as simple as gas that has not reached the pilot yet or a dead battery, or it can be a worn sensor, a dirty pilot assembly, a gas pressure problem or air movement in the vent. Owners can rule out the simple ones.

Standing pilot: the checks you can make

1. Confirm gas is reaching the houseIf other gas appliances such as the range or water heater work normally, the supply to the house is fine. With propane, check the tank gauge. A whole-house supply problem is a call to the utility or propane supplier.
2. Start from OFF and waitTurn the knob to OFF and wait the full time on the label before trying again. Valor's and Mason-Lite's instructions both specify five minutes so any gas can clear, and Valor adds to smell for gas, including near the floor, before relighting.
3. Hold the knob as long as the label saysHold times vary. Valor's manual for one fireplace says to keep holding for about 10 seconds; a Mason-Lite vented log manual says about one minute after the pilot lights. Regency's guidance is that if the pilot does not stay lit when released, repeat and hold longer before letting go.
4. Allow for an idle seasonNapoleon notes that after a long period of non-use it can take time for air to clear from the line before gas reaches the pilot. Repeating the label procedure, with the waits, is the safe way to handle this.
5. Stop after a few triesValor's instruction is that if the pilot will not stay lit after several tries, turn the control knob to OFF and call a service technician or the gas supplier. Repeated attempts beyond that add risk without adding information.

Electronic ignition: the checks you can make

• The wall switch. Some systems will not respond to the remote unless a switch on the wall or the unit is on. Regency's Gi27LE manual is one example.
• Batteries in the remote and the receiver. Valor recommends replacing receiver and remote batteries at least once a year. Regency's guidance links a weak battery to no spark at the pilot. Use the battery type the manual specifies, and only as many as it calls for.
• Thermostat settings. Napoleon suggests checking a thermostat remote: turn it to its highest setting or switch it to manual mode to rule out a setting that is simply not calling for flame.
• Lockout. After repeated failed sparks the board may lock out. The manual describes the reset; Regency's is to turn the system off, wait five minutes and start again.
• A pilot that went out by design. If your model has a timed or on-demand pilot, a pilot that is out after several days of disuse may be normal behavior.
• Listen. Note whether you hear sparking, see a pilot flame that then disappears, or get nothing at all. That detail helps the technician.

Describe the failure precisely

A technician can work faster when the description is exact. These patterns each point to a different part of the system, though none of them is a diagnosis on its own:

• The pilot lights but dies the moment you release the knob. The safety circuit is not holding the valve open, which leads a technician to the pilot flame, the thermocouple and the valve.
• The pilot stays lit, but the burner will not come on. The pilot side is working; attention moves to the thermopile, the switch or remote circuit, and the valve.
• It runs for a while, then shuts down. Something changes once the unit is hot or the burner is running, such as the pilot flame being pushed away from its sensor.
• It goes out on windy days or when exhaust fans run. Air movement in the vent or the room may be disturbing the pilot.
• Sparks but never lights, or no spark at all. Typical electronic-ignition questions: gas reaching the pilot, the igniter, power and batteries.
• The pilot flame looks small, yellow or lazy. Regency's manual says a small, probably yellow pilot flame means the pilot is not reaching the burner or flame sensor properly and calls for a dealer visit.

What a technician looks at

Napoleon recommends that thermocouple and thermopile problems be troubleshot and repaired by a certified fireplace technician, and lists the thermocouple, thermopile and gas valve among parts that may need replacement. A service call on a pilot that will not stay lit usually covers:

• The shape and position of the pilot flame on its sensor, and cleaning of the pilot assembly.
• Electrical output of the thermocouple or thermopile, or the flame sensor signal on an electronic system.
• Gas pressure at the appliance and the operation of the valve.
• Whether logs, embers or decorative media have shifted into the pilot area. Valor's manual, for example, warns to keep the area inside its pilot shield clear of fire glass.
• The vent and its termination outside, since a blocked or damaged vent affects how the appliance burns.

Some manufacturers' tips describe owners lightly cleaning sensors. Our advice is to leave the parts of the pilot assembly and gas control to a technician, because a sensor bent out of position or a disturbed fitting creates a new problem on top of the old one.

Where Chimney 911 fits

We service gas fireplaces, gas logs and inserts, including the venting and the chimney they rely on. Our gas work connects appliances to a gas line that is already in place; we do not run or extend gas lines. A problem with the supply itself, such as no gas at the meter, a utility shutoff or a propane delivery, belongs with the utility, the propane supplier or a plumber. See gas fireplace service and what an annual gas fireplace cleaning covers.

Questions homeowners ask

Sources

1. Valor, 1800 series gas fireplace installation and owner's manual
2. Regency Fireplace Products, Fireplace Care FAQ
3. Regency, Gi27LE gas insert owner's and installation manual
4. Napoleon, Why Your Gas Fireplace Keeps Going Out
5. Mason-Lite (Masonry Fireplace Industries), Virginiana vented gas log standard burner manual
6. PSE&G, I Smell Gas

This guide is general information. It can't diagnose a specific chimney; an inspection can.