Two wall switches next to a gas fireplace almost always split one simple job in two: one switch controls the fireplace itself (power to the ignition system, or the pilot circuit on older units), and the other controls the blower fan that circulates warm air into the room. The confusing part is that the two switches usually look identical and neither one is labeled, so there’s no way to tell which is which just by looking.
How to Figure Out Which Switch Does What
The fastest way to sort this out is to test it directly rather than guess:
- Turn on the fireplace using whichever switch (or remote/wall control) normally starts the flame, and let it run for several minutes so the firebox has time to heat up.
- Leave the second switch off at first, and check whether a fan comes on by itself once the unit reaches temperature. Many blowers are thermostatically controlled and won’t run until the firebox is warm, even with the switch flipped on — so give it a few minutes before concluding anything.
- If nothing changes, flip the second switch. If a fan noise starts (or the flame becomes visibly more turbulent from air movement), that switch controls the blower.
- If flipping the second switch does nothing at all, the fan may not be thermostatically ready yet, the blower motor may be faulty, or the switch may be wired to something unrelated to the fireplace (a nearby outlet or light circuit is not unusual in a room that was wired all at once).
What Each Switch Typically Controls
Switch 1: Power / ignition
On most gas fireplaces, one switch is the main power switch for the appliance’s ignition system — either a standing pilot that needs to be lit first (with the switch then controlling the main burner) or, on newer units, an electronic ignition system that lights the pilot and main burner together when switched on.
Switch 2: Blower fan
The second switch is almost always the blower fan, which pulls room air across the hot firebox and pushes it back out into the room — it doesn’t affect the flame itself, only how much of that heat actually reaches the room versus radiating locally around the fireplace. Running the fireplace without the blower is completely normal; it just means less forced air circulation.
If the Second Switch Doesn’t Seem to Do Anything
A few real possibilities, roughly in order of likelihood:
- The blower hasn’t warmed up yet. Most blowers are on a thermal switch that won’t engage until the firebox is hot, regardless of the wall switch position.
- The blower motor has failed. If the fireplace has run for 15-20 minutes and gotten visibly hot with no fan noise at all, the blower itself may need replacement — see how to know if your fireplace has a blower for how to confirm whether one is even installed.
- The switch controls something else entirely. Not every switch near a fireplace is wired to the fireplace — check whether it’s tied to a nearby outlet, accent lighting, or another circuit before assuming it’s fireplace-related.
If you’ve ruled these out and still can’t identify what a switch does, that’s a reasonable point to call a licensed electrician or your fireplace’s installer rather than keep guessing at wiring you can’t see behind the wall.
FAQ
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