black powdery droppings on top of gas ater heater

Old 01-22-01, 10:29 AM
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I have noticed black, grainy droppings on the top of our gas water heater around the exhaust pipe. Is this an indication that I should check something out?
Old 01-22-01, 07:18 PM
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Signs Of Soot


What your discribing sounds like soot. Soot is carbon caused by the incomplete combustion of gas.

The water heater needs to be serviced as soon as possible. Most likely there is an accumulation of lint/dust etc. clogging up the secondary air opening on the burner tube.

Other causes for soot is an overgassed burner, restricted internal flue, warpped or collapsed baffle inside the internal flue, lack of air in the closet <etc.> where the tank is located or restricted air intake openings on the bottom of the tank.

This is a condition that needs to be checked asap. If the tank is old, it may need to be replaced. If newer and not serviced to correct the sooting condition, it won't last long.

If this condition is left unchecked, the soot will further clog up the burner compartment and flue until it becomes unserviceable, if not already.

Based on the tanks age, the current amount of soot already accumulated will determine what needs to be done if anything orther then replacement.

There is one other remote possiblity. Those particles might just be rust from the vent pipe or those from the roofing shingles.

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