We're totally baffled, this heater was spotless inside a week ago, took of the hood, vacuumed the leaves out, vacuumed around the burner tray, heater worked fine (only 2 years old to boot). Today I see a message, no pilot sensed so I open up the front and inside looks like a bunch of cobwebs and just strange stuff. Maybe some part of the heater caught fire and melted? The display still comes on, the wires don't seem melted but the inside is covered with this mess. Hoping someone with experience has perhaps seen this before and can shed some insight. We'll be taking it all apart soon, maybe that'll reveal the cause.