This part fits: ALPHA BOILERS CD32C (BOILER COMPLETE) ALPHA BOILERS CD13R (BOILER COMPLETE) ALPHA BOILERS CD18R (BOILER COMPLETE) ALPHA BOILERS CD24R (BOILER COMPLETE) CD25C (HEAT EXCHANGER) CD25C (ALL PARTS) CD28C (HEAT EXCHANGER) CD28C (ALL PARTS) CD35C (HEAT EXCHANGER) CD35C (ALL PARTS) CD30S (HEAT EXCHANGER) CD30S (ALL PARTS) CD25X (HEAT EXCHANGER/FAN ASSY) CD25X () CD28X (HEAT EXCHANGER/FAN ASSY) CD28X ()