Patent ID: 7162980

Claim:
Fuel-fired heating apparatus comprising: a combustion chamber; a first fuel burner disposed within said combustion chamber and operable to create a flame therein, said first fuel burner being cloggable by particulate matter entrained in primary combustion air delivered thereto during firing thereof; a second fuel burner operable to create a flame and having associated therewith a structure cloggable by particulate matter entrained in primary combustion air delivered to said second fuel burner during firing thereof; an air supply system for supplying primary combustion air from outside said combustion chamber to said first and second fuel burners without exposing the supplied primary combustion air to the interior of said combustion chamber on its way to said first and second fuel burners; and a shutdown system for monitoring the condition of said second fuel burner flame and terminating combustion within said combustion chamber when said condition is indicative of a predetermined degree of clogging of said second fuel burner.