A.O. Smith Copper Boiler DB-1210

Shut off electric and gas supply to the burner

Install standpipe in tee of inlet/outlet line

Pour required amount of UN•LIME into unit through standpipe

Direct solution into suitable container with hose

Remove cover panel from far side of water connections

Expose the heat exchanger return bends

Remove return bends using a 9/16" deep socket ratchet

Inspect tubes to ensure they are free of scale and deposits

Remove deposits with a stiff wire brush or mechanical tube cleaner to bare metal

Is the circulating pump properly sized for the application?

Oil the three oil cups (2 on the motor, 1 on the pump) as instructed on the oil tube supplied with the unit

Add 2 or 3 teaspoonfuls in bearing oil cups

Add 10 or 12 drops in the motor oil cups

Main Burner Flame Characteristics

Check for complete combustion of gas

Ensure rapid ignition and carryover of flame across entire burner

Verify reasonably quiet operation during initial ignition, operation, and extinction

Check for no excessive lifting of flame from burner ports

Is there any accumulation of lint or foreign material restricting air openings?

Clear any lint or foreign material from air openings

Turn off the electrical power, main manual gas shutoff and pilot valves.

Allow boiler parts to cool before disassembly.

Remove the internal flue collector and vent pipe running to the chimney.

Check parts and chimney for obstructions and clean as necessary.

Remove burners from boiler and other metal parts as required to clean as necessary.

Refer to parts list supplied with this manual for disassembly aid.