A.O. Smith TC-099 manual

Variable Fire Boiler

Domestic Hot Water/Hydronic Heating

VF Boiler

MODELS COVERED

VW and VB 500, 750, and 1000 Models

Series 100 and 101

Part No. TC-099

Service Handbook

Part No. TC-099 • Printed in the U.S.A. • 0407

COMMERCIAL

Visit the “Information Central” link of

www.hotwater.com for a listing of

available Service Handbooks.

For additional information contact:

A. O. Smith Water Products Company

A Division of A. O. Smith Corporation

500 Tennessee Waltz Parkway

Ashland City, TN 37015

1-800-527-1953

www.hotwater.com

Contents

Main Variable Fire Boiler Domestic Hot Water/Hydronic Heating VF Boiler Service Handbook COMMERCIAL A. O. SMITH WATER PRODUCTS COMPANY VF BOILER SERVICE MANUAL Technical Training Department 2007 CONTENTS INTRODUCTION Page EMC 5000 MODULATION CONTROL SYSTEM UIM - USER INTERFACE MODULE - OVERVIEW UIM - USER INTERFACE MODULE - STATUS LIGHTS UIM - USER INTERFACE MODULE - USER INPUT BUTTONS Page UIM - USER INTERFACE MODULE - MENU SCREENS UIM - USER INTERFACE MODULE - MENUS PRINCIPLES OF OPERATION LI4LI3 NR/L1 W/T3V/T2U/T1 VFD See the important service notes on page 34 PRINCIPLE OF OPERATION (CONT) Gas Valve Venturi Operation - Gas Train Combustion Air Fuel Gas Venturi Blower Burner See the important service notes on page 34 PRINCIPLE OF OPERATION (CONT) Config Key - Blower Speed Programming Memory Chip SEQUENCE OF OPERATION SEQUENCE OF OPERATION (CONT) START UP PROCEDURE Prior To Start Up Firing Modes - Min/Max/Mod Turning The Boiler Off NEVER TURN THE BOILER OFF BY SECURING POWER WHILE IT IS FIRING. Repeated START UP PROCEDURE (CONT) Start Up Procedure START UP PROCEDURE (CONT) Adjusting Manifold Gas Start Up Note: High Fire CO2 Settings Low Fire CO POOR COMBUSTION - IGNITION PROBLEMS Adequate Combustion - Proper Venting Direct Vent Installations: Conventional Vent Installations: If the boiler is using room air for combustion ensure POOR COMBUSTION - IGNITION PROBLEMS (CONT) Burner Inspection Firing Rate - Modulation Performance Procedure Page Vent uri Manifold Gas Pressure Check Service Note: Gas Valve Gas Train Shut Off Valve Blower CONTROL PANEL LAYOUT Blower Prover Switches MCB - MODULATING CONTROL BOARD - OVERVIEW MCB / CCB / FCB Terminology Explanation MCB - MODULATING CONTROL BOARD - OVERVIEW (CONT) Wiring and connection details given here reference 100-101 Series VF boilers. IMPORTANT NOTE - MCB CIRCUIT BOARD ORIENTATION MCB - SECTION A A MCB - SECTION B B MCB - SECTION C C MCB - SECTION D MCB - SECTION E E MCB - SECTION F This section of the MCB contains the communication or Comm ports: The MCB circuit board is mounted upside down on VF boilers compared to the illustrations below. F ICSP External Comm Internal Comm MCB - SECTION G 1 2 3 G SW2 MCB SECTION H H PDB - POWER DISTRIBUTION BOARD - OVERVIEW Wiring and connection details given here reference 100-101 Series VF boilers. A TB1 PDB - SECTION B B PDB - SECTION C The upper right corner of the PDB contains the following: J2 Pin Numbers J2 Socket C J2 Socket 24 VAC Outputs J1 Socket Transformer PDB - SECTION D JP3 J3 Pin Numbers J3 Socket JP1 Jumper PDB - POWER SUPPLY TEST Power Test Procedure: Note: JP3 Jumper JP1 Jumper ERROR MESSAGES - TROUBLESHOOTING Use the System Status menu when troubleshooting: Things to check before servicing: Resetting the EMC 5000 control: IMORTANT SERVICE REMINDER: ERROR MESSAGES UIM Display Is Blank Display Fail No Config Key Config Key CRC Config Key Part Low AC Voltage Low 24 VAC Low Water Low Gas No Flow Pump IS NOT Running Pump Relay Note: VB Field Installed Pump Note: VB Models - No Factory Pump VW Models - Factory Pump Installed No Flow Pump is Running Sequence Err Ignition Speed Mtr Spd < Min Spd Switches) Page Page Three conditions can cause this error message Prover Switches) Helpful Troubleshooting Note: Three conditions can cause this error message Determine if Low BPS is causing the lock out. Helpful Troubleshooting Note: Three conditions can cause this error message Determine if High BPS is causing the lock out. Three conditions can cause this error message Pressure Reading Test Blocked Flue TEMPORARILY DISCONNECT THE TWO WIRES TO THE BLOCKED FLUE SWITCH Flame Stg1 Page Flame Stg1 (cont) REMEMBER TO RE-OPEN THE GAS TRAIN SHUT OFF VALVE. Igniter Stg1 BOILER CONTROLS Page Controlling Probe INTERNAL TEMPERATURE CONTROLS Operating Set Point - User Setting Oper Setpnt The Operating Set Point is always active The Operating Set Point reacts to temperature sensed by the Controlling Probe. When Stage 1 Differential Setting - User Setting Stage1 Diff INTERNAL TEMPERATURE CONTROLS (CONT) Automatic High Limit - User Setting Hi Limit Dead-band Operational Note: Automatic High Limit Differential - User Setting Hi Limit Dif EXTERNAL CONTROLS Enable/Disable Control Circuit EXTERNAL CONTROLS (CONT) Types of External Controls Aquastat EMS Outdoor Air Reset Control OPERATING TEMPERATURES Input Power and Circuit Protection: Input Specifications: Input Specifications (cont): Ignition Timing: Default User Settings/Ranges: VW MODELS DEFAULT SETTING ADJUSTABLE RANGE VB MODELS DEFAULT SETTING ADJUSTABLE RANGE BOTH MODELS DEFAULT SETTING ADJUSTABLE RANGE GLOSSARY GLOSSARY (CONT) UIM - User Interface Module: VFD: Water Flow Switch: Variable Fire Boiler Domestic Hot Water/Hydronic Heating VF Boiler Service Handbook COMMERCIAL