My natural gas fireplace has a mind of it's own.

It has been working properly until today--it decided to come on by itself

It has been cold (15 degrees) here in SC--could this be the problem??

The pilot remains on and seems to be find.

My service man came and disconnected the control valve from it's electrical source and the fireplace remained on--strange at best.

Finally disconnected all wires to control valve and fireplace went off.

  • What is the make and model of the fireplace? Also is it electronic ignition or standing pilot. Did the technician remove the switch wires from the unit when it shut off finally? And lastly do you have a thermostat, remote, or switch controlling the fireplace?
    – Mnc123
    Feb 27, 2015 at 15:15
  • Untrue. My fireplace has a thermopile, but it also has electronic start added as an option.
    – longneck
    Feb 27, 2015 at 15:21
  • Do you have a standing pilot on your fireplace? Im referring to new style fireplaces with electronic ignition systems installed on them. Not a standing pilot with an electronic ignitor
    – Mnc123
    Feb 27, 2015 at 15:40

4 Answers 4


Some gas fireplaces with electric start have a thermopile that generates enough electricity to keep the valve open, even if you disconnect the mains electricity. So if the fireplace was on already and you disconnect the main power, I would expect the fire to stay on.

However, starting by itself is not a good thing. I would look at two components: the control board the the thermopile and solenoid connect to, or the remote control receiver. If you do have a remote control receiver, it's easy to eliminate that as the problem because you can just disconnect it. Otherwise, just replace the control board.

  • Electronic ignition fireplaces do not have thermopiles or thermocouples. A flame sensor senses when pilot is lit. These fireplaces require either continuous power or a battery pack to operate
    – Mnc123
    Feb 27, 2015 at 15:18

On most fireplaces I've seen (non-electronic start), a thermocouple provides enough power, along with the initial press/hold of the solenoid, to keep the solenoid open for the pilot light to remain lit.

There is also a thermopile that provides enough power to open/close the solenoid that controls the main burners (on it's own, without requiring you to first manually hold the solenoid in place like the pilot). A switch between the thermopile (Tp) and Thermostat (Th) contacts on the valve is what opens/closes the solenoid. So if the fireplace is stuck on, I would think it's one of two things:

  1. There is a short in the controller and power is always being provided to the solenoid. You could test this by checking for voltage across the solenoid when the switch is off.

  2. The solenoid is stuck open. Similar to #1, if there is no voltage, but it is open, it's likely stuck.


Mine just started on its own while I was using a dell laptop i n the room. I could not shut it off with the remote control, had to close the gas valve. Glad I was home. This is a "Sure heat" savanna, purchased thru home depot a few years ago. Have problems every year, must replace the batteries very often, but never new it could come on by itself. May tear it out and replace, or just use manually.

  • is the problem corrected with new batteries?
    – Ed Beal
    Mar 28, 2017 at 14:26

My house was either hit by lightning or lightning struck very close by. It was the loudest explosion I have ever heard in my life. It was then pitch black and all power was out in the area. It is late summer. Downstairs some items on the mantle were knocked to the floor. The fireplace was blazing and it must have been 90 degrees downstairs. The lightning actually ignited the gas fireplace?

  • 1
    Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Sep 15, 2019 at 11:34

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