Why does my pilot light make a hissing noise?
A soft, steady hiss from a lit pilot is normal — it is just gas flowing through a tiny orifice, the same sound a gas stove burner makes. What is not normal is a loud hiss, a whistling or roaring hiss, or a hiss you hear when the fireplace is completely off. That last one can mean a gas leak, and you should shut the gas off, leave, and call us.
The normal hiss versus the one that means trouble
Every standing pilot pushes a small stream of gas through a pinhole orifice, and that produces a faint, even hiss you can only hear up close with the room quiet. As long as the flame is a steady blue with a little yellow tip and the sound does not change, that is just the pilot doing its job. The hisses worth investigating are the ones that got louder, took on a whistle or a flutter, or came with a weak, split, or lifting flame.
When a hiss turns into a whistle or roar
A pilot orifice is barely wider than a needle, so it does not take much to disturb the flow. Spiders and dust are the classic culprits in our mountains — they build webs and egg sacs right in the pilot tube over the off-season, and the partly blocked path can make the gas whistle or the flame sputter. Gas pressure that is off, or a pilot hood that got bumped out of alignment, can do the same. This is exactly the kind of thing our annual tune-up catches: we clean the pilot assembly and burner ports before you are depending on the heat.
The hiss you should never ignore
If you hear a hiss when the fireplace is off and every knob is closed, or you smell rotten eggs along with it, treat it as a possible gas leak. Do not hunt for the source, flip switches, or light anything — leave the house and call us from outside. Our line answers 24/7. Running or repairing a gas line is licensed work in North Carolina, and diagnosing a leak is ours to do, not a DIY job. Call (828) 545-0525.
Related questions
- Why is my pilot flame weak, small, or split?
- Why does my pilot light blow out on windy days?
- Can spiders or insects clog a gas fireplace pilot?
- Why does my gas fireplace pilot light keep going out?
- Why does my fireplace smell like rotten eggs even when it's off?
- Why won't my gas fireplace turn on at all?
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