Inspected oil furnace after customer reported soot throughout house following service by another company. Found incorrect nozzle size had been installed previously, causing extensive soot accumulation in mechanical room, clean-outs, burn chamber, and chimney. Tagged out and shut down furnace due to safety hazards from improper venting through baro damper. Advised customer that heat exchanger replacement would be required and recommended chimney cleaning; scheduled consultation for gas furnace conversion options.
