A.O. Smith VB/VW- 750 Venting Maintenance, HeatExchangerPreventativeMaintenance, Deliming

lines with air or water and clear or replace the blocked portions of the line as necessary. Note that areas of the drain line which include a sag or low spot in the line will also form a condensate trap which can be removed by levelling the tube and does not indicate a blocked system.

Inspect the metal vent drain and vent collector drain connectors at six month intervals­. Remove the hoses from the connections, then check with a small wooden dowel or plastic rod passed up through the metal connection­ to insure the passage is clear, using caution to not bend or damage the connector. Call a

qualified service agent to inspect and correct the problem if any

obstructions are found in the connectors. Replace all hoses and clamps immediately after inspection­ and before starting the boiler in accordance with the Lighting and Operating Instructions. DO

NOT OPERATE THE BOILER UNLESS ALL CONDENSATE DRAIN LINES ARE PROPERLY CONNECTED AND WORKING.

When a means to neutralize condensate has been installed you must also follow operating, inspection and maintenance

procedures specified by the manufacturer of the product. Inspect

the installed device to insure that it does not cause condensate to remain in the boiler or vent for any reason.

Venting Maintenance

It is recommended that the intake and exhaust piping of the appliance be checked every 6 months for dust, condensate leakage, deterioration and carbon deposits.

Qualified service agent should follow this procedure when the boiler’s intake and exhaust piping need cleaning:

1.Turn off the electrical power, and manual gas shut-off.

•Allow boiler parts to cool before disassembly.

2.Remove the vent pipe.

•Check parts and chimney for obstructions and clean as necessary.

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

•Refer to parts list for disassembly aid.

4.Clean and reinstall the parts removed in steps 2 and 3.

•Be sure the vent pipe has a minimum upward pitch of 1/4" per foot (2cm/m) of length and is sealed as necessary.

5.Restore electrical power and gas supply to boiler.

•Check for gas leaks and proper boiler and vent operation.

HeatExchangerPreventativeMaintenance

In most water supply systems solids exist.As the water is heated, these tend to drop out depositing as scale or lime.This scale must be removed before the heat exchanger tubes become blocked.

Deliming

The amount of calcium carbonate (lime) released from water is in direct proportion to water temperature and usage. The higher the water temperature or water usage, the more lime deposits are dropped out of the water. This is the lime scale which forms in pipes, boilers and on cooking utensils.

The usage of water softening equipment greatly reduces the hardness of water. However, this equipment does not always remove 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 5°F (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.

Tube Cleaning Procedure 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” (1.6mm) 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.

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 for more information.

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

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