How long do I hold the pilot knob down when lighting it, and why won't it stay lit if I let go too soon?
Hold it down about 30 to 60 seconds after the pilot flame catches. That flame has to heat a small sensor called the thermocouple until it makes enough electrical signal to hold the gas valve open on its own. Let go too soon and the sensor is still cold, so the valve snaps shut and the pilot goes right back out.
What's actually happening in those 30 seconds
When the pilot lights, it starts heating a thermocouple — a pencil-tip sensor sitting right in the flame. As it heats, it produces a tiny electrical current, and that current is what holds the safety gas valve open. The whole point is that the valve physically cannot stay open unless something is proving the pilot is burning. When you press and hold the knob, you're manually keeping the valve open while the sensor warms up to take over. Thirty to sixty seconds is how long that handoff takes. Release early and the sensor is still cold, so the valve does exactly what it's designed to do — closes and kills the gas.
If it still won't stay lit after a full minute
Then the problem isn't your timing — it's the hardware, and it's time to stop cycling the knob. The usual suspects around here: a pilot orifice clogged by spiders and dust after the off-season, a weak or misaligned thermocouple that can't make enough signal anymore, or a lazy pilot flame that isn't wrapping the sensor properly. On a drafty flue at elevation, a downdraft can even blow a healthy pilot around. None of those are DIY fixes — cleaning or replacing the thermocouple and pilot assembly is licensed gas work.
Where we come in
This is one of the most common — and least expensive — repairs we run. Often it's a cleaning or a small, affordable part, quoted upfront before any work begins. If your propane tank recently ran empty or the gas was off for service, there may also be air in the line that takes a few tries to purge — that's normal. But if you smell gas, leave and call from outside. Otherwise, reach us at (828) 545-0525 and we'll get it holding again.
Related questions
- How do I light the pilot light on my gas fireplace?
- What do the OFF, PILOT, and ON positions on my gas fireplace control knob mean?
- How long should I wait before trying again if the pilot doesn't catch on the first try?
- Is it safe to relight the pilot myself, or should a professional do it?
- Does a gas fireplace with electronic ignition have a pilot light I need to light myself?
- Do I have to take the glass off my gas fireplace to get to the pilot light?
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