I don't know that there are any plumbing issues regarding standing pilot vs electronic ignition.

Pilot lights are designed to shut off if they go out, so that gas doesn't build up. They have a thermocouple that senses that the flame is out and closes the gas valve. I don't understand the "needs to breathe in case the pilot goes out" comment.

As a compromise, you can shut this off completely during the warmer months and just leave the pilot on during the cold months.

I'm not a big fan of standing pilots in general. It seems particularly wasteful on something that isn't used often, like a fireplace.

Thanks for your input.

What I meant by the "need to breathe" comment was that without proper ventilation (such as the doors of the fireplace remaining open), the pilot tends to go out by itself. I still don't really understand why that would be.

Secondly, I agree with shutting off the pilot during the non-winter months when the fireplace is not being used. But for clarification - are you referring to shutting off the gas completely at the gas line in the basement or just letting the pilot go out and having it shut off thru the thermocouple?

If the pilot tends to go out with the doors closed, it's because the flame is short on oxygen. Hard for me to imagine your doors are so tight to do that, but anyway, if that is the case, the thermocouple would prevent gas from continuing to flow if it went out. But to be extra safe you could either leave the doors open a crack to keep the pilot running, or get in the habit of turning off the gas to the pilot.

As for CO2, I would think it's not a problem, since ventless fireplaces are used with the pilot running all the time. My folks have two and use them all winter long, leaving at least the pilot on, and that's in rooms without any vent or chimneys.

Actually, they have gas ventless heaters (not fireplaces), but the principle is the same.

Thanks.

(1)I agree with you about the fireplace doors. They are definitely not so tight that air couldn't get in there. I still can't figure why the manufacturer said that. CYA I guess.

(2) During the non-winter months, would you suggest shutting the gas off at the main in the basement even though I have a safety feature on the thermocouple?

(3) Have your parents had any issues with leaving their standing pilots on all year long with their ventless heaters?

Probably not a good idea to rely on a thermocouple for that, so shut it off somewhere (nearby valve? - or valve in basement otherwise)

My parents have not had any problems with leaving the pilot on for months at a time. It's off in the summer, otherwise it's on. (they use to turn it on/off years ago, but it got to be a pain for them to relight while holding the primer in for 60 seconds, etc,. Now they just leave it on and deal with the extra gas cost, whatever that is.)

Have you tried the fireplace forum?

http://ths.gardenweb.com/forums/firepl/

Thanks for your replies. Yes - I did try the fireplace forum and got no replies, so I figured I try plumbing since its really related to gas hookups.

There will be a shutoff valve on the control body that you can use to turn the entire thing off during the warmer months. It will have something like "Off, Pilot, On" positions marked on it.

Use that shutoff rather than the thermocouple safety. You don't want to use safety controls as operational controls.

Agree. Actually, I was just planning on shutting off the gas valve in the basement that the gas line of the fireplace is connected to. That way - no gas can even get to the pilot or burner assembly and its easy to do.