Gas Fireplace Pilot Light Repair

Common Causes of Pilot Light Problems

In most cases, a pilot that won't stay lit traces back to one of a handful of components. We carry the most common parts on the truck, so once we find the cause we can usually fix it the same visit.

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  Faulty thermocouple (most common) — The thermocouple sits directly in the pilot flame and generates a small voltage that tells the gas valve it's safe to stay open. When it wears out, shifts out of position, or gets coated with oxidation, that voltage drops below what the valve needs — so the valve closes and the pilot dies, even if the flame looked fine to you a moment ago.
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  Weak thermopile — The thermopile is a set of thermocouples wired in series that generates the millivoltage powering the gas valve and the whole control system — wall switches, remotes, all of it. As it ages or accumulates buildup, the output voltage falls. Once it drops too low, the valve won't stay open reliably, and you'll see the pilot die mid-cycle or refuse to hold after relighting.
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  Dirty or clogged pilot orifice — The pilot orifice is a tiny brass fitting that controls exactly how much gas reaches the pilot. Dust, spider webs, and mineral deposits can partially block it over time, and the result is a weak or flickering flame that can't heat the thermocouple enough to hold the valve open. The safety system shuts the gas off — but the real cause is just a dirty fitting that needs to be cleaned.
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  Draft issues pulling out the flame — The pilot flame is small and pretty vulnerable to air movement. Air sneaking in from a poorly sealed firebox, an open or improperly dampered flue, or pressure shifts from nearby exhaust fans can push just enough air across the pilot to put it out — and it'll happen over and over even when every component tests perfectly fine. Draft is one of the trickier causes to catch.
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  Low gas pressure — The pilot needs enough gas pressure to produce a flame hot enough to satisfy the thermocouple. If pressure is too low — a partially closed shutoff, a regulator problem, or something at the meter — the flame stays weak and the valve cuts off, even if the thermocouple itself is perfectly fine. It's less common than the other causes, but worth checking when everything else tests out.

How We Diagnose Pilot Light Issues

1. 1
   Observe the pilot behavior — We watch the pilot through a full ignition cycle and note exactly when it fails. Does it light and immediately drop? Hold for a few seconds, then die? Each pattern tells us something different about where to look next.
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   Test thermocouple and thermopile output with a multimeter — We put a millivolt meter on both components under load. If the reading is outside the acceptable range, we've confirmed the failure — no guessing, no replacing parts that didn't need it.
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   Inspect gas flow and pressure — We check the pilot orifice for blockage, verify gas pressure at the valve, and make sure nothing upstream is cutting the supply short. When the thermocouple and thermopile test fine, this step usually pinpoints the cause.

Should You Try Relighting It First?

Standing Pilot vs. Intermittent Pilot (IPI)

Not all gas fireplaces work the same way. Knowing which ignition type you have changes how we diagnose the problem — and what the fix involves.

The failure points and the repair approach are completely different depending on which system you have. We work on both — and we'll tell you up front which type you've got and exactly what the fix looks like.