Gas Logs Sales, Installation & Service Across the Upstate

Most residential gas logs use a standing pilot. You push in the control knob, which lets gas flow to the pilot, and press the igniter to light it. The pilot flame then heats a small sensor. Until that sensor is hot enough, the gas valve will not hold itself open, which is why you have to hold the knob for 30 seconds or so before letting go.

If the pilot goes out the moment you let go, the sensor is not doing its job. On many sets that sensor is a thermocouple, a thin copper-colored rod that produces a tiny voltage when heated. Thermocouples wear out, get knocked out of the flame when logs are moved, and lose contact at the valve. Testing one takes a meter and a few minutes.

If the pilot stays lit but the burner will not come on from the wall switch or remote, look at the thermopile. It sits in the pilot flame too, but it generates enough power to run the valve and the switch circuit with no house electricity. A weak thermopile, a loose switch wire or a corroded terminal will leave you with a pilot and nothing else.

And if there is no pilot flame at all, the cause is usually gas not arriving: the key valve is off, the pilot orifice is clogged with dust or debris, or spiders have nested in the pilot tube over the summer. Spider webs in gas appliances are a real, common problem, and they are cleared with careful cleaning, not a coat hanger.

• Pilot will not light: gas off, clogged pilot orifice, insects in the tube, failed igniter
• Pilot lights, goes out on release: thermocouple, pilot flame too small, loose connection at the valve
• Pilot stays lit, burner will not come on: thermopile, wall switch, remote receiver batteries, wiring
• Vent-free logs shut off after a while: oxygen depletion sensor tripping, dirty ODS pilot, poor room air

Vented gas logs are decorative. They burn with tall, yellow flames that look like a wood fire, and their exhaust goes up the chimney. Because of that, the chimney damper must stay open whenever they are installed, and the fuel gas code requires the damper on a vented decorative set to be fixed open, usually with a clamp. Vented logs give off some heat, but most of it goes up the flue.

Vent-free logs are heaters. They burn hotter and cleaner with a mostly blue flame, and their exhaust stays in the room. That makes them very efficient, but it also means the moisture and combustion products they produce stay in the house with you. Every vent-free set has an oxygen depletion sensor, a precision pilot that shuts the gas off if the oxygen in the room starts to fall. Manufacturers limit vent-free logs to rooms of a minimum size and often limit run times, and the code restricts unvented heaters in bedrooms and bathrooms.

You can tell which you have from the rating label, usually on a chain or plate under the burner. The difference matters for service: log placement on a vent-free set is exact, because a log in the wrong spot interrupts the flame and makes soot and carbon monoxide. On either type, never add extra logs, rocks or decorative glass that did not come with the set.

A yearly service before the first fire heads off most no-heat calls. We shut the gas off, pull the logs and grate, vacuum the burner and pan, and clean the pilot assembly and the ODS if there is one. We check the thermocouple or thermopile output with a meter, test the ignition, and inspect the flexible connector and valve for leaks.

Then we set the logs back in exactly the pattern the manufacturer shows, light the set, and watch the flame. Correct flame color and height depend on the logs being placed right and the burner ports being clear. On vented sets we confirm the damper is open and fixed. We also check that there is a working carbon monoxide alarm nearby, and we will tell you if there is not.

Sooty glass doors, logs that have crumbled or cracked, embers that have broken down to dust, and rusted burner pans are all things we look at and report. Some of that is cosmetic. Some of it changes how the set burns.

We sell gas log sets, and the first question is not which logs look best. It is vented or vent-free. Vented sets give the tall, yellow flame of a wood fire and send their exhaust up the chimney, so they need a working flue and a damper fixed open. Vent-free sets are built to heat the room, burn with a mostly blue flame, and come with room-size and run-time limits. If you mainly want the look, vented is the usual answer. If you want heat in a room that gets cold, vent-free may be, as long as the room and the fireplace qualify.

Then the set has to fit the firebox. We measure the front width, back width, depth and height of your fireplace, because every burner and log set lists the minimum firebox it needs. A set that is too big crowds the flame into the logs and soots; one that is too small looks lost. Factory-built metal fireplaces add a rule of their own: a vent-free set can only go in one that is listed for vent-free use, which is on the fireplace's own label.

Last is the gas. If there is no line at the hearth, the set needs one, sized for its BTU rating with everything else on the meter, plus a shutoff valve you can reach. We tell you that before you buy, along with the fuel the set has to be built for, natural gas or propane, and the ignition type that suits how you will use it.

• Vented or vent-free, based on whether you want the look or the heat
• Burner and logs sized to your measured firebox
• Listed for your fireplace type, masonry or factory-built
• Built for your fuel, natural gas or propane
• Standing pilot, millivolt with a wall switch or remote, or electronic ignition
• A gas line and key valve at the hearth if there is not one

Plenty of older Upstate homes have a wood-burning masonry fireplace and no gas anywhere near it. Converting one to gas logs starts with a gas line: from the nearest suitably sized pipe, or a new branch from the meter, to the hearth, with a shutoff valve where you can reach it. The familiar key valve in the floor or wall beside the hearth is one way to do that, and it has to be accessible and identified.

The line is sized for the log set's BTU rating along with everything else on the meter, permitted, pressure-tested and inspected like any other new gas line. Before the logs go in, the chimney itself should be clean and sound, because a vented set depends on it to carry exhaust out. Chimney sweeping and masonry repair are their own trades, and we will tell you if we see a reason to call one.

For a fireplace insert, the venting is the insert installer's work and must follow the manufacturer's instructions exactly. We run the gas supply and valve to the insert, connect it, test it and service its burner and controls.

Any appliance that burns gas makes some carbon monoxide, and a properly adjusted one makes very little. Problems start when combustion goes wrong or exhaust has nowhere to go: a vented set with the damper closed, a blocked chimney, logs placed so they disturb the flame, or a vent-free set running in a small closed room for hours.

The basics are simple. Have a working carbon monoxide alarm on each level and outside sleeping areas. Never close the damper on vented logs. Follow the run-time and room-size limits on vent-free logs, and crack a window if the manufacturer calls for it. If the flame changes color or soot appears, stop using the set and have it looked at.