[Ruuduser]

One of my furnaces had a new ignitor installed last year, so I wonder if this is part of it. The unit has not been serviced since the ignitor was installed. There are two burner ports. The port with the ignitor has a bunch of sand like grit around it. Its not the soot that people talk about with CO and incomplete combusion. Anyone know what causes this, i.e, is it a problem?

 

[kenmac]

How is it vented ?? Most likely comming from the vent... I 've seen this when vented into chimney

 

[Ruuduser]

Its a furnace vent, all metal tubing - joins with the water heater vent at about 10 feet. Its vented straight up, two floors to the roof. So I say about 25 ft. Downdraft unit. Probably a good amount of cooldown before the exhaust makes it to the roof. Flame on this unit has always looked the same since I can remember. I was wondering if it somehow came with the gas (gas company getting grit into the system?). This unit leads the other one in usage.

Other identical unit in the attic is laid horizontal, vents up about 5 ft - never had that grit, but also hasn't had a new ignitor since it was last serviced.

 

[kenmac]

Doubt it came from gas co.. Most likley came from the inside the vent. condensation.. I've seen it most when vented with single wall vent

 

[yuri]

When nat. gas burns there is a small amount of sulphur in the flue gas. Probably condensing in the vent and falling back down. See that in the cleanout cap of base tees often.