terryrwood

I neither have a humidifier, nor a water softener.

I'm being told its most likely sulfur burning off from the LPG.

No humidifier, we felt like humidity was a bit high so we just borrowed a de-humidifier.. Problem with powder has been around for years.

Sorry for double posting, I relied to a previous post and my comment was buried on page 2. I have a problem in a home with unvented Gas Heaters, putting off a white powder from the flames, this white powder is pretty annoying it gets on the walls, furniture, tv screen and eventually builds up on the thermopile and the pilot goes out. I've heard people wanting to blame it on leaks in humidifiers and vents, or sheet rock dust, but none of that applies here. they have called it salts but I've see salt residue from water evaporating this is more like baby powder and does not taste like salt, (yea I did) its pretty much tasteless. In the attached image you can see how thick it builds up where I wiped my finger across deflector above the refractory tiles. Click to Enlarge 70.07 KB