When the gas fireplace will not turn on

First: is there any smell of gas?

Before touching the fireplace, stop and smell. If there is any odor of gas near the fireplace or anywhere in the house, do not try to light it, do not flip light switches or unplug anything, and do not use a phone indoors. Get everyone outside, then call the gas utility, or 911 if the utility cannot be reached. Gas fireplace manuals give exactly these steps, because a switch or a phone can make a spark.

Propane is heavier than air, so a propane leak can collect near the floor, and the manuals warn that the added odor can fade over time. If you are unsure, assume a leak. Nothing below applies until the house has been cleared.

Know which kind of unit you have

Which checks apply to a gas fireplace not turning on depends on how it lights, and gas fireplaces light in one of two ways. A standing-pilot unit keeps a small pilot flame burning whenever it is set to on or pilot, and its control knob has positions such as off, pilot and on. It works without house power. An electronic-ignition unit has no pilot burning between uses. When you call for heat, a control module sparks the pilot and then lights the burner, and it needs house power, a battery pack or both.

The rating plate and the lighting instructions tell you which you have. They are on a label or tag behind the lower grille or near the controls, along with the brand and model number. Keep the owner's manual nearby for the steps below; if it is lost, the maker's site may have it under the model number.

Check the gas supply

Each gas fireplace has a shutoff valve of its own, a small valve that can sit behind the lower grille, in the floor beside the unit or in a nearby wall box. A lever valve is open when the handle lines up with the pipe and closed when it sits across it. If someone closed it for cleaning or for the season, the fireplace has no gas to light.

Check whether other gas appliances work. If the range or water heater is also out, the problem is the supply to the house, and the call goes to the gas utility or, on propane, the supplier. On a propane system, look at the tank gauge. If the tank ran empty, do not relight anything yourself. Call the supplier to refill it, because the fuel gas code calls for the piping to be checked for leaks when gas is turned back on after an interruption of service.

Check the switch, the remote and the receiver

When the fireplace does nothing at the press of the remote, it may be fine; the signal may not be getting through. Replace the batteries in the handset first. Then find the receiver, a small box behind the lower grille or near the valve, which can have batteries of its own and a slide switch marked on, remote and off.

Set that slide switch to on. If the burner lights, the fireplace works and the problem is the remote, its batteries or its pairing with the receiver, which the remote's manual explains how to reset. If the unit has a wall switch, try it the same way. Remotes with a thermostat mode also stay quiet when the room is already warmer than the set temperature, so check the setting before assuming a fault.

Standing-pilot units: the knob and the pilot

On a standing-pilot unit, look at the control knob. If it sits at pilot, the pilot may be burning but the burner cannot come on from the switch or remote; turn it to on. Then look through the glass or the viewing port for the pilot, a small blue flame near one end of the burner.

If the pilot is out, it can be relit by following the lighting instructions on the label and in the manual, step by step. Those instructions begin by turning the knob to off and waiting five minutes to clear out any gas, then smelling for gas, including near the floor, and stopping if there is any odor. The rest of the steps set the knob to pilot, press and hold it, light the pilot with the igniter button, and hold the knob in for as long as the label specifies before letting go.

If the pilot lights and then goes out when you let go, that is a separate fault, with its own guide for when a gas fireplace pilot light won't stay lit.

Electronic-ignition units: power, batteries and lockout

When a gas fireplace won't ignite and it has electronic ignition, power is the first check. Check that the outlet it plugs into has power and that the breaker has not tripped. If the unit has a battery pack for power outages, fresh batteries may be all it needs. The manual for these units says not to try to light the burner by hand, so it starts from the switch, the remote or the unit's own controls.

Ignition modules make a set number of attempts and then stop, and some lock out. The manual describes the reset, such as turning the unit off and removing power for a short time, then trying again. One reset after a power outage or a long idle stretch is reasonable. If it locks out again, stop there.

Clicking with no flame

If a gas fireplace is clicking but not lighting, the igniter works: the clicking is the spark. When nothing lights, the spark has nothing to light or the unit cannot tell the pilot is burning. Gas may not be reaching the pilot because the shutoff valve is closed or the propane tank is empty, both of which you can check. After gas work on the house or a propane refill, air in the line can delay lighting, and that is a job for the service visit, not repeated clicking.

Beyond those checks, the causes are inside the unit: a dirty or blocked pilot, a spark jumping to the wrong place through a cracked insulator, or a flame sensor the module cannot read. None of those is a homeowner repair, because each one means opening the sealed firebox or the control compartment.

Where the owner's checks end

Once the unit has to be opened, it is a service call. Call when:

• You smell gas at any point (leave first, and phone the gas utility or 911 from outdoors).
• The pilot will not light, or will not stay lit, after following the lighting instructions carefully.
• The igniter clicks with no flame after the valve, tank and batteries have been checked.
• The ignition module locks out again after one reset.
• The burner lights and then goes out after running for a while.
• Flames look tall, dark or sooty, or soot is building on the glass.
• The glass is cracked, or any part of the controls has been under water.

What happens on a service visit

A technician works from the maker's service chart for your model. On a standing-pilot unit that means reading the thermocouple and thermopile output with a meter and testing the switch circuit at the valve. On an electronic unit it means taking the module through its lighting sequence and checking the spark, the gas at the pilot and the flame sensor. Gas pressures are read at the valve against the rating plate, and any connection that is opened is leak-checked before the unit is handed back. Our gas fireplace repair page describes that work in detail.