How does a gas fireplace work during power outage?

[h8go4s]

During a recent power outage, I flipped on the wall switch for my gas fireplace, knowing it wouldn't work. But it did. So I was able to keep the house warm for 18 hours until the power came back on. Being a curious type, I dug out the installation manual, and it shows a transformer and a battery pack. But I can't find a battery pack. I emailed Heatilator customer support, which replied "Your GNDC33 does not have a battery pack. All you have to do is turn on your wall switch." Not much help, and contradicts my manual. So I'm still curious. If there's no battery, what is the power source that opens the gas valve during a power outage? If there is a battery, it must be inside the wall between the switch and the fireplace casing. I'm wondering how long the battery works (it's over 8 years old now) and how to get at it. Does anyone have experience with this?

Ron.

[swamptiger]

Some gas heaters and appliances don't need 120v power to operate the burner - they have either a standing pilot or piezo (spark) ignition and the thermocouple is operated with millivolts. My guess is the battery pack would be used to operate a circulating fan, but I'm not familiar with your specific unit.

[Deep]

You have a pilot light system, no power need for the flame to come on, you would need power(110/120 volt) if you have/or want to use the blower. The wall switch is just completing the circut allowing the gas valve to open.

No battery either.

[delcecchi]

You have a pilot light system, no power need for the flame to come on, you would need power(110/120 volt) if you have/or want to use the blower. The wall switch is just completing the circut allowing the gas valve to open.

No battery either.

So the thermocouple generates enough electricity to power the gas valve?

[Bigtom]

I don't know the answer but our heater does the same thing. It is a free standing heater with seperate controls for the flame and blower, no thermostate. It's nice to know you can still heat the house with the power out.

[Ice Chicken]

The unit has a thermopile which is basicly a thermocouple on steroids.it provides enough juice to operate the pilot and the gas valve.

[Fishinguy40]

Yes. The thermocouple generates enough electricity to operate the gas valve.

[ChuckN]

My freestanding propane stove doesn't need electricity to operate the stove (like other's have explained), but I do need electricity to run the blower. On my particular model I have to use the blower or it won't produce any substantial heat.

When the power goes out I have a small converter I attach to a deep cycle battery, and I can plug in the blower motor (plug into the wall type) and it will operate. The small blower runs a long time on one battery. This has saved our house a couple times now in extreme weather.

[MNice]

They operate just like 99% of fishhouse heaters, and old natural draft water heaters.

[pikechaser]

they use a thermopile which when its heated by the pilot generates a small amount of electricity. much less than 1 volt dc. The gas valve is designed to operate on that small amount of electricity. A thermopile is a bunch of small thermocouples hooked together in series to crank up the output. In this type of system you have to use special thermostats/ on-off switches, becuase any extra resistance in the circuit may cause it to not work

[Bigsmitty]

The inside of the Thermopile or Thermogenerator there is a series of quartz rods. When heated by the pilot flame it creates what we call a millivolt current. This is enough current to operate a switch or thermostat to open and close the gas valve.