A.O. Smith 405, 400, 402 Replacement Parts, Tubecleaningprocedure Mechanical Removal of Deposits

all of the hardness (lime). For this reason it is recommended that a regular schedule for deliming be maintained.

The time between cleaning will vary from two to six months depending upon water conditions and usage. A change of approximately 5oF (3°C) in the normal temperature rise through the boiler is usually an indication that scale should be removed. For long life, copper or brass is recommended for all valves, pipe and fittings.

TUBECLEANINGPROCEDURE

MECHANICAL REMOVAL OF DEPOSITS

Establish a regular inspection schedule, the frequency depends on the local water conditions and severity of service. Do not let the tubes clog up solidly. Clean out deposits over 1/16" (1.6 mm) thickness.

To service heat exchanger tubes, remove return header casting on the side opposite the water connections. Use a U.S. standard 5/8" deep socket ratchet to remove the nuts, exposing the tube ends. Inspect to ensure tubes are free of scale and deposits. If scaled, remove deposits with a stiff wire brush or mechanical tube cleaner to bare metal. Reinstall return header casting. Flush system.

Note: Removal of the heat exchanger is not required.

CAUTION

IF HEAT EXCHANGER MAINTENANCE REQUIRES TUBING REPLACEMENT, SPECIAL PROVISIONS SHALL BE TAKEN TO ENSURE THAT THE DAMAGED TUBES ARE CAREFULLY REMOVED.

REPLACEMENT TUBES MUST BE PROPERLY INSTALLED AND EXPANDED INTO THE ROLLED TUBE TUB.

OVER-ROLLING, MISALIGNMENT OF TUBES OR IMPROPER TIGHTENING OF THE ASSEMBLY MAY RESULT IN LEAKS OR DAMAGE TO THE HEAT EXCHANGER. CONTACT YOUR A. O. SMITH DEALER FOR DETAILED INSTRUCTIONS.

REPLACEMENT PARTS

Replacement parts may be ordered through A. O. Smith dealers, authorized servicers or distributors. Refer to the Yellow Pages for where to call or contact (in United States) the A. O. Smith

Water Products Company, 500 Tennessee Waltz Parkway, Ashland City, TN 37015, 1-800-433-2545 or (in Canada) A. O. Smith Enterprises Ltd., 768 Erie Street, Stratford, Ontario, Canada N5A 6T3, 519-271-5800. When ordering parts be sure to state the quantity, part number and description of the item including the complete model and serial number as it appears on the product. Refer to the parts lists (P/N 212513-000) for more information.

For Technical Assistance call A. O. Smith Technical Information Center at 1-800-527-1953.

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