Pennco Sooting / Incomplete Combustion

Boiler produces soot or black staining around vent

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Insufficient combustion air, Incorrect gas pressure or orifice size, Dirty heat exchanger, Blocked flue

How to Fix / Troubleshooting

Critical safety warning: Sooting indicates dangerous combustion and potential carbon monoxide. Turn off the boiler and do not operate it until corrected.

Shut down: Turn off power and gas to the boiler.
Check vent and air: Inspect vent and combustion air paths for blockages.
Do not clean and restart without testing: A technician must clean the burner and heat exchanger and perform combustion analysis.

Repair Difficulty

Professional Required 5/5

Required Part

Boiler Heat Exchanger

Check Price on Amazon

We may earn a commission from links on this page.