A.O. Smith TC-099 manual

V ariable Fire Boiler Domestic Hot W ater/Hydronic Heating VF Boiler MODELS COVERED VW and VB 500, 750, and 1000 Models Series 100 and 101 Part No. TC-099 S e r v i c e H a n d b o o k Part No. TC-099 • Printed in the U.S.A. • 0407 ©2007 A. O. Smith Corporation COMMERCIAL V isit the “Information Central” link of www .hotwater .com for a li[...]

A. O. SMITH WATER PRODUCTS COMPANY VF BOILER SERVICE MANUAL Technical Training Department ©2007 CONTENTS Introduction... .............. ................. ................. .............. ...... Qualification s.............. .............. ................. .............. ......... Service W arning................... .............. ................[...]

VF BOILER SERVICE MANUAL AOS WPC - Tech Training 2 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent INTRODUCTION This Service Manual is designed to aid in servicing and tro ubleshooting A. O. Smith VF boilers. Models VW/VB 500 - 1000 - series 100/101 boilers ar e covered in this manual. The instruction[...]

AOS WPC - Tech Training 3 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL T ools Required • Instruction Manual that came with the boiler . • Hand tools common to in stallation and service of commer cial water heaters and boilers. • T ORX® T40 or 5mm hex wrench - for se[...]

VF BOILER SERVICE MANUAL AOS WPC - Tech Training 4 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent EMC 5000 MODULATI ON CONTROL SYSTEM This portion of the serv ice manual will cover the EMC 5000 Modulation Control system (EMC - Energy Managem ent Control). The EMC 5000 cont rol system includes several[...]

AOS WPC - Tech Training 5 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL UIM - USER INTERFACE MODULE - OVERVIEW The UIM is an assembly that consists of several electr onic component s. The main circuit board in the assembly is the UIB (User Interface Board) wh ich houses the[...]

VF BOILER SERVICE MANUAL AOS WPC - Tech Training 6 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent UIM - USER INTERFACE MODULE - ST ATUS LIGHT S LCD display 4 line x 20 character System S tatus Firing Rate LEDs 5 T ouch Sensitive User Input Buttons System Status LED Lights Firing Rate Status The three[...]

AOS WPC - Tech Training 7 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL UIM - USER INTERFACE MODU LE - USER INPUT BUTTONS Select Button is used to: • Enter menu screens. • Activate adjustment mode for various settings. The [ > ] will be flashing slowly to the left of[...]

VF BOILER SERVICE MANUAL AOS WPC - Tech Training 8 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent UIM - USER INTERFACE MODU LE - CHANGING SETTINGS 1 2 3 4 5 6 The sequence of UIM scre en displays below is an example of ho w to navigate the menus to change the Operating Set Point. Scree n Dis play 1: [...]

AOS WPC - Tech Training 9 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL UIM - USER INTERFACE MODULE - MENU SCREENS At the top center of the UIM panel is the display LCD. This LCD is used to provide information to the user through menu activated screens. Within each of the s[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 10 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent UIM - USER INTERFACE MODULE - MENUS Log & System Info Screen: This screen displa ys the following: • Elapsed hours of operation (T otal time system has been powered up). • Number of running min[...]

AOS WPC - Te ch Training 11 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL PRINCIPLES OF OPERATION VF boilers do not ha ve a gas orifice. The blower “pulls” gas from the gas valve into a V enturi attached to the suction (inlet) side of the blower (p age 12). As the speed[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 12 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent PRINCIPLE OF OPERATION (CONT) V enturi Operati on - Gas T r ain A V enturi is connected to the in let side of the combus tion blower on VF Boilers. The gas line from the outlet of the gas valve connect[...]

AOS WPC - Te ch Training 13 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL PRINCIPLE OF OPERATION (CONT) Blower Speed V erificatio n - Hall Effect Sensor The MCB (page 25) initiates bl ower operation by cl osing the VFD enable/disable circuit AND sending a 1-10 VDC speed ins[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 14 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent PRINCIPLE OF OPERATION (CONT) Config Key - Blower Speed Programming The Config Key is an 18” long cable with a plug on one end and an EEPROM memory chip sealed at the other . The Conf ig Key plugs in[...]

AOS WPC - Te ch Training 15 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL SEQUENCE OF OPERATION MCB board applies power to pu mp relay Pump I s Ener gized Flow Switch Closes Contacts NO Boiler enters Service Mode and locks out. UIM displays No Flow Error messa ge MCB Board [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 16 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent SEQUENCE OF OPERATION (CONT) MCB Senses Minimum 2.7 AC Amps Through Ignitor Gas Valve Is Energized Fuel Gas Is Drawn Into Blower Inlet By Venturi Assembly Mixed With Combustion Air Boiler ente rs Servi[...]

AOS WPC - Te ch Training 17 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL S T ART UP PROCEDURE Prior T o St art Up In addition to normal supplies and hand tools necessary for inst alling and servicing water heaters and boilers the following tools and test equipment shou ld [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 18 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent S T ART UP PROCEDURE (CONT) St art Up Procedure 1. Before starting the boiler , please review th e boilers Instruction Ma nual supplied with the boiler . Ensure the water piping, gas line, controls, an[...]

AOS WPC - Te ch Training 19 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL S T ART UP PROCEDURE (CONT) Adjusting Manifold Gas 13. Set the boiler to Max Mode (F iring Modes - page 17). Check combustion readings using combustion analyze r . Compare CO 2 readings taken to the h[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 20 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent POOR COMBUSTION - IGNITION PROBLEMS If the high and /or low fire CO 2 combustion readings are not in accordance with the tables shown on page 19, the CO readings are high, or if the boiler is experi en[...]

AOS WPC - Te ch Training 21 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL POOR COMBUSTION - IGNI TION PROBLEMS (CONT) Burner Inspection 2. Remove the burner and inspec t the burner for any signs of damage or debris inside. If the burner is damaged or c ontaminated with debr[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 22 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent POOR COMBUSTION - IGNI TION PROBLEMS (CONT) VFD Operating Parameters Approximate MCB/VFD operating parameters for natural gas m odels are shown in the first table below . Parameters for propane mo dels[...]

AOS WPC - Te ch Training 23 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL POOR COMBUSTION - IGNI TION PROBLEMS (CONT) Manifold Gas Pressure Check 5. Attach Digita l manometer to one of the manifold gas pressure tap s on gas line between the boiler ’s 24 V AC gas valve ou [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 24 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent CONTROL PANEL LAYOUT The illustration below shows the control p anel on VF boilers. Blower Prover Switches VF boilers are equipped with High and Low blower prover switches or BPS. Both are normally ope[...]

AOS WPC - Te ch Training 25 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL MCB - MODULATING CONT ROL BOARD - OVERVIEW MCB / CCB / FCB T erminology Explanation MCB and CCB are separate terms that refer to the same circ uit board which is the main controller for the EMC 5000 c[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 26 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent MCB - MODULATING CONTROL BOARD - OVERVIEW (CONT) The MCB circuit board is the ma in controller . All instructi ons for burner modulation and temperature control originate from this circuit board. Diagn[...]

AOS WPC - Te ch Training 27 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL MCB - SECTION A The upper left corner of the MCB cont ains the following sockets/component s: Red LED (illuminated when the F1 fuse is open or missing) F1 Fuse (7.5 amp auto motive fuse - 24 V AC tran[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 28 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent MCB - SECTION B The upper middle section of the MCB contains the fo llowing socket s/components: † J4 Socket (Outputs/Inputs) • Pin 1 - S pare - not used • Pin 2 - S pare - not used • Pin 3 - S[...]

AOS WPC - Te ch Training 29 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL MCB - SECTION C The upper right corner of the MCB contains the following sockets/component s: J2 Socket (Pump relay coil; IRI gas valve) • Pin 1 - 120 V AC switched hot wire to pump relay coil • P[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 30 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent MCB - SECTION D MCB Master Control Dip Switches System configurations are m ade on the MCB circuit boards wit h dip switches. This page explains how the Master Control dip switches (SW1) are configured[...]

AOS WPC - Te ch Training 31 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL MCB - SECTION E The lower left corner of the MCB c ontains the following socket s/components: J6 Socket (Gas valve relay - N/A on VF boilers) • Pin 1 - 24 VDC gas valve relay circuit • Pin 2 - N/A[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 32 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent MCB - SECTION F This section of the MCB contains the communication or “Comm” ports: ICSP Port The ICSP port (In Circuit Serial Progra mming) is us ed for pro gramming t he MCB board . DO NOT plug a[...]

AOS WPC - Te ch Training 33 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL MCB - SECTION G Along the bottom edge of the MCB there is a second dip sw itch (SW2). This page det ails and explains the SW2 dip switch. There are 3 switches on SW2: switch 1 is a spare, switch 2 mus[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 34 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent MCB SECTION H This section of the MCB contai ns a small “Daughter Board” th at cont ains the J23 and J24 sockets. Refer to p age 25 for more information. The VFD (page 1 1), the Hall Effect sensor [...]

AOS WPC - Te ch Training 35 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL PDB - POWER DISTRIBUTI ON BOARD - OVERVIEW The PDB provides connection points for li ne-input (120 V AC) power , the pump, and the transformer . It distributes the line-input power and the transform e[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 36 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent PDB - SECTION A The left side of the PDB circuit board cont ains a terminal strip (TB1) used to connect the 120 V AC power supply to the boiler , the pump relay , and the pump motor . VW models will ha[...]

AOS WPC - Te ch Training 37 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL PDB - SECTION B The mid section of the PDB contai ns the fusing for the following: F1 Fuse - 10 amp 240 V AC - European Models only † F2 Fuse - 20 amp 120 V AC - Pump F3 Fuse - 3 amp 120 V AC - Tran[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 38 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent PDB - SECTION C The upper right corner of the PDB contai ns the following: J2 Socket (24 V AC Outputs) • Pin 1 - 24 V AC Hot to MCB J3 Socket • Pin 2 - 24 V AC Return to MCB J3 Socket • Pin 3 - G[...]

AOS WPC - Te ch Training 39 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL PDB - SECTION D The lower right corner of the PDB contains the J3 Socket and the JP1 jumper . The J3 Socket is described here the JP1 jum per is described on page 40. J3 Socket (120 V AC Outputs) • [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 40 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent PDB - POWER SUPPLY T EST The lower right cor ner of the PDB also contains two jumpers and three pow er supply status LED lights. With power applied the green DS2 LED should always be lit. The JP1 jumpe[...]

AOS WPC - Te ch Training 41 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES - T ROUBLESHOOTING The EMC 5000 control system performs exhaustive self diagnostics and displays detected fault conditions on the UIM (page 6). There are approximately 80 dif ferent err[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 42 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR UIM Display Is Blank Boiler is turned off 120 V AC power supply problems 24 V AC power supply problems Blown Fuses Defective transform[...]

AOS WPC - Te ch Training 43 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Display Fail” Communication between the MCB and UIM has been interrupte d - the MCB is having trouble communicating with [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 44 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Config Key CRC” Data read fro m the Config Key by the MCB was not properly confirmed at power up. The Config Key cont ains[...]

AOS WPC - Te ch Training 45 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Low AC V olt age” Power supply polarity is reversed. Lin e voltage to boiler is less than 90 V AC. • Ensure po wer supp[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 46 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “No Flow” Pump IS NOT Running (If pump is running pr oceed to the next page) Normally open cont acts on factory mounted flo[...]

AOS WPC - Te ch Training 47 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “No Flow” Pump is Running (If pump is not running go to the preceding page) Normally open cont acts on factory mounted flo[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 48 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Sequence Err” Enable/disable circuit wires to VFD disconnected. 1-10 VDC instruction wires to VFD disconnected. 1-10 VDC i[...]

AOS WPC - Te ch Training 49 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower IS NOT St arting (If the blower is st arting procee d to the “Blower Prov S tg1” Blower Is [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 50 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower IS NOT St arting (If the blower is st arting proceed to the “Blower Prov S tg1” Blower Is St[...]

AOS WPC - Te ch Training 51 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower IS NOT St arting (If the blower is st arting procee d to the “Blower Prov S tg1” Blower Is [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 52 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower Is St arting (If the blower is not st arting go to the “Blower Prov S tg1” Blower Is Not Sta[...]

AOS WPC - Te ch Training 53 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower Is St arting (If the blower is not st arting go to the “Blower Prov S tg1” Blower Is Not St[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 54 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower Is St arting (If the blower is not st arting go to the “Blower Prov S tg1” Blower Is Not Sta[...]

AOS WPC - Te ch Training 55 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blower Prov S tg1” Blower Is St arting (If the blower is not st arting go to the “Blower Prov S tg1” Blower Is Not St[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 56 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Blocked Flue” MCB senses the normally closed Blocked Flue (Exhaust) pressure switch cont acts are op en. Import ant Servic[...]

AOS WPC - Te ch Training 57 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Flame Stg1” Flame or ig nition failure. Error message displaye d after 1 or 3 losses of flame or after 1 or 3 failed tria[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 58 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Flame Stg1” (cont) Flame or ig nition failure. Error message displaye d after 1 or 3 losses of flame or after 1 or 3 faile[...]

AOS WPC - Te ch Training 59 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Flame Stg1” (cont) Flame or ig nition failure. Error message displaye d after 1 or 3 losses of flame or after 1 or 3 fail[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 60 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent ERROR MESSAGES (CONT) DISPLAYED MESSAGE CONDITION/INDICATES CHEC K/REPAIR “Igniter St g1” MCB is not sensing minimum igniter current of 2.7 AC amps during the igniter warm up period. Import ant Ser[...]

AOS WPC - Te ch Training 61 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL BOILER CONTROLS Boiler controls that are improperly in stalled or set up can cause serious operat ional and service related problems such as short cycling. This section provides i nformation for how v[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 62 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent BOILER CONTROLS (CONT) Primary System Control A Primary System Control is a top level “system” temperatur e control. A Pr imary System Control activates the call for heat or enables boiler operatio[...]

AOS WPC - Te ch Training 63 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL BOILER CONTROLS (CONT) Controlling Probe The Operating Set Point on the VF boiler ’s EM C 5000 control system r eacts to temperature sensed by the Controlling Probe. The EMC 5000 control system can [...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 64 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent BOILER CONTROLS (CONT) INTERNAL T EMPERATUR E CONTROLS (CONT) Automatic High Limit - U ser Setting “Hi Limit” The Automatic High Limit is a “local” EMC 5000 User Setting that can be adjusted th[...]

AOS WPC - Te ch Training 65 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL BOILER CONTROLS (CONT) EXTERNAL CONTROLS Enable/Disable Control Circuit The Enable/Disable Control Circuit is always active. This control circuit must be “closed” to enable boiler operati on. T wo[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 66 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent BOILER CONTROLS (CONT) EXTERNAL CON TROLS (CONT) T ypes of External Controls An External Control can be a Pr imary System Control or a Supe rvisory Control or both. The enable/disable circuit described[...]

AOS WPC - Te ch Training 67 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL OPERATING T EMPERATURES T emperature rise through the boiler: 20 - 40°F . The temperature rise ( Δ T = Delta T) through the boiler should be ma intained between 20 - 40°F while firing at 100%. This[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 68 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent T ECHNICAL SPECIFICATIONS Input Power and Ci rcuit Protection: Input Specifications: † Power Supply Voltage 120 VAC †. See pa ge 40 for PDB power supply test procedu re. 108 VAC RMS minimum; 132 VA[...]

AOS WPC - Te ch Training 69 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL T ECHNICAL SPECIFICATIONS Input Specifications (cont): † Output Specifications: † High Blower Pr over Pressur e Switch †. Signal level p assed through switches: 24 V AC @ >7ma. (Does not requ[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 70 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent T ECHNICAL SPECIFICATIONS Ignition Timing: Default User Settings/Ranges: As shipped from the factory the SW1 dip switches (page 30) on the MCB are preset to the appropriate values according to the syst[...]

AOS WPC - Te ch Training 71 of 72 Ashland City, TN © 2007 Servicing sh ould only be performed by a Qualified Service Agen t VF BOILER SERVICE MANUAL GLOSSARY Δ T: Symbol used for “Delta T .” E ngineering term to conv ey “temperature rise” or “difference” through a boiler or heat exchanger . IE: If the inlet water temper ature to a boi[...]

VF BOILER SERVICE MANUAL AOS WPC - Te ch Training 72 of 72 Ashland City, TN © 2007 Servicing shou ld only be performed by a Qualified Service Agent GLOSSARY (CONT) UIM - User Interface Module: Plastic housing that hol ds the UIB, LCD, and TSB. Provides means to both send and receive information from the user . Only one cable to the MCB is required[...]

V ariable Fire Boiler Domestic Hot W ater/Hydronic Heating VF Boiler MODELS COVERED VW and VB 500, 750, and 1000 Models Series 100 and 101 Part No. TC-099 S e r v i c e H a n d b o o k Part No. TC-099 • Printed in the U.S.A. • 0407 ©2007 A. O. Smith Corporation COMMERCIAL V isit the “Information Central” link of www .hotwater .com for a li[...]