A.O. Smith VB/VW 500/750/1000 - Manual

Start-up Instructions

VB/VW 500/750/1000

Series 100/101

Before starting the boiler, please review the boilers instruction manual (AOS Part Number 212800) supplied with the boiler. This

is a powered combustion copper tube boiler. Please contact an authorized A.O. Smith representative before starting the unit.

Ensure that the water piping, gas line, controls, and venting have been installed per the instruction manual.

Gas supply lines should be sized in accordance with the current edition of National Fuel Gas Code (ANSI Z223.1/NFPA 54) or

CAN/CSA B149.1 The Canadian Natural Gas and Propane Installation Code.

Make sure the boiler is not damaged. If the unit is damaged, contact an A.O. Smith representative for service or replacement

parts prior to starting the boiler.

This boiler is equipped with a Modulating EMC 5000 control system. The EMC 5000 displays the system status and errors that may

occur during normal operation. For full details on the controls, please refer to the Installation Manual supplied with the boiler. The

boiler must be installed according to the instructions provided with the unit. Failure to do so will void the warranty.

The following test equipment should be on hand: (all test equipment must be acclimated to ambient temperature before calibration

and use.)

• A combustion analyzer capable of measuring CO and CO

2

or O

2

.

• A digital manometer or pressure gauges capable of accurately displaying 0 – 15 (± .01) inches of water column.

• Combination volt/ammeter

• TORX® T40 or 5mm hex wrench – for setting gas mixture at gas valve

• 3mm or 7/64 in hex wrench – for setting gas mixture at gas valve

I. Verify utilities

• Ensure that the water piping, gas line, controls, and venting have been installed per the instruction manual.

• Be certain that the system is full of water, that air is purged from all lines, the boiler, and storage tank.

• Ensure that no leaks are present and that all supply and return water valves are open.

• Upstream gas valve should remain closed until start up.

II. Component Sequence Verification

• Ensure that the power supply meets these requirements: single phase, Minimum: 108 VAC RMS; Maximum: 132 VAC RMS

and is on a dedicated circuit breaker with separate neutrals and grounds.

• Ensure all control wiring is run in a dedicated conduit per instruction manual.

• Perform power supply test outlined in the instruction manual.

• Ensure that the upstream manual gas valve of the boiler is open.

Prior to turning on the gas, proper sequence of most of the system can be verified. With the water turned on, and the gas turned

off by the downstream manual valve, start the system and allow it to run through a heating cycle. It should stop when it checks for

the flame and declare a fault. This will verify that the pump, flow switch, igniter, variable frequency drive, modulating gas valve,

blower and low/ high blower prover switches are all functioning properly.

III. Initial Boiler Set-up Verification

• Drill a maximum 7/16” hole in the side of the vent boot tee approximately 8” from back panel to insert the gas analyzer probe.

The hole must be sealed upon completion of the start-up testing.

• Open the downstream manual gas valve to the boiler and purge air from the line.

PRINTED 0608

212936-002