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  5. Service Handbook

A.O. Smith TC-099 Service Handbook

Manual is about: Variable Fire Boiler Domestic Hot Water/Hydronic Heating 100 Series, 101 Series

Summary of TC-099

  • Page 1

    Variable fire boiler domestic hot water/hydronic heating vf boiler m o d e l s c o v e r e d 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 ©2007 a. O. Smith corporation commercial visit the “information central”...

  • Page 2: Contents

    A. O. Smith water products company vf boiler service manual technical training department ©2007 contents introduction....................................................................... Qualifications.................................................................... Service warning................

  • Page 3

    Vf boiler service manual aos wpc - tech training 2 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent introduction this service manual is designed to aid in servicing and troubleshooting a. O. Smith vf boilers. Models vw/vb 500 - 1000 - series 100/101 boile...

  • Page 4

    Aos wpc - tech training 3 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual tools required • instruction manual that came with the boiler. • hand tools common to installation and service of commercial water heaters and boilers. • t...

  • Page 5

    Vf boiler service manual aos wpc - tech training 4 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent emc 5000 modulation control system this portion of the service manual will cover the emc 5000 modulation control system (emc - energy management control). ...

  • Page 6

    Aos wpc - tech training 5 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual uim - user interface module - overview the uim is an assembly that consists of several electronic components. The main circuit board in the assembly is the...

  • Page 7

    Vf boiler service manual aos wpc - tech training 6 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent uim - user interface module - status lights lcd display 4 line x 20 character system status firing rate leds 5 touch sensitive user input buttons system st...

  • Page 8

    Aos wpc - tech training 7 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual uim - user interface module - user input buttons select button is used to: • enter menu screens. • activate adjustment mode for various settings. The [ > ]...

  • Page 9

    Vf boiler service manual aos wpc - tech training 8 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent uim - user interface module - changing settings 1 2 3 4 5 6 the sequence of uim screen displays below is an example of how to navigate the menus to change ...

  • Page 10

    Aos wpc - tech training 9 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent 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 throu...

  • Page 11

    Vf boiler service manual aos wpc - tech training 10 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent uim - user interface module - menus log & system info screen: this screen displays the following: • elapsed hours of operation (total time system has been...

  • Page 12: Vfd

    Aos wpc - tech training 11 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual principles of operation vf boilers do not have a gas orifice. The blower “pulls” gas from the gas valve into a venturi attached to the suction (inlet) sid...

  • Page 13

    Vf boiler service manual aos wpc - tech training 12 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent principle of operation (cont) venturi operation - gas train a venturi is connected to the inlet side of the combustion blower on vf boilers. The gas line ...

  • Page 14

    Aos wpc - tech training 13 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual principle of operation (cont) blower speed verification - hall effect sensor the mcb (page 25) initiates blower operation by closing the vfd enable/disabl...

  • Page 15

    Vf boiler service manual aos wpc - tech training 14 of 72 ashland city, tn © 2007 servicing should 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 s...

  • Page 16

    Aos wpc - tech training 15 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual sequence of operation mcb board applies power to pump relay pump is energized flow switch closes contacts no boiler enters service mode and locks out. Uim...

  • Page 17

    Vf boiler service manual aos wpc - tech training 16 of 72 ashland city, tn © 2007 servicing should 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...

  • Page 18

    Aos wpc - tech training 17 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual start up procedure prior to start up in addition to normal supplies and hand tools necessary for installing and servicing water heaters and boilers the fo...

  • Page 19

    Vf boiler service manual aos wpc - tech training 18 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent start up procedure (cont) start up procedure 1. Before starting the boiler, please review the boilers instruction manual supplied with the boiler. Ensure ...

  • Page 20

    Aos wpc - tech training 19 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual start up procedure (cont) adjusting manifold gas 13. Set the boiler to max mode (firing modes - page 17). Check combustion readings using combustion analy...

  • Page 21

    Vf boiler service manual aos wpc - tech training 20 of 72 ashland city, tn © 2007 servicing should 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 re...

  • Page 22

    Aos wpc - tech training 21 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual poor combustion - ignition problems (cont) burner inspection 2. Remove the burner and inspect the burner for any signs of damage or debris inside. If the ...

  • Page 23: Blower Speed Control Vfd

    Vf boiler service manual aos wpc - tech training 22 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent poor combustion - ignition problems (cont) vfd operating parameters approximate mcb/vfd operating parameters for natural gas models are shown in the first...

  • Page 24: Venturi

    Aos wpc - tech training 23 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual poor combustion - ignition problems (cont) manifold gas pressure check 5. Attach digital manometer to one of the manifold gas pressure taps on gas line be...

  • Page 25

    Vf boiler service manual aos wpc - tech training 24 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent control panel layout the illustration below shows the control panel on vf boilers. Blower prover switches vf boilers are equipped with high and low blower...

  • Page 26

    Aos wpc - tech training 25 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual mcb - modulating control board - overview mcb / ccb / fcb terminology explanation mcb and ccb are separate terms that refer to the same circuit board whic...

  • Page 27

    Vf boiler service manual aos wpc - tech training 26 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent mcb - modulating control board - overview (cont) the mcb circuit board is the main controller. All instructions for burner modulation and temperature cont...

  • Page 28

    Aos wpc - tech training 27 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual mcb - section a the upper left corner of the mcb contains the following sockets/components: red led (illuminated when the f1 fuse is open or missing) f1 f...

  • Page 29

    Vf boiler service manual aos wpc - tech training 28 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent mcb - section b the upper middle section of the mcb contains the following sockets/components: † j4 socket (outputs/inputs) • pin 1 - spare - not used • p...

  • Page 30

    Aos wpc - tech training 29 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual mcb - section c the upper right corner of the mcb contains the following sockets/components: j2 socket (pump relay coil; iri gas valve) • pin 1 - 120 vac ...

  • Page 31

    Vf boiler service manual aos wpc - tech training 30 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent mcb - section d mcb master control dip switches system configurations are made on the mcb circuit boards with dip switches. This page explains how the mas...

  • Page 32

    Aos wpc - tech training 31 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual mcb - section e the lower left corner of the mcb contains the following sockets/components: j6 socket (gas valve relay - n/a on vf boilers) • pin 1 - 24 v...

  • Page 33

    Vf boiler service manual aos wpc - tech training 32 of 72 ashland city, tn © 2007 servicing should 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 programming) is used for pr...

  • Page 34

    Aos wpc - tech training 33 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual mcb - section g along the bottom edge of the mcb there is a second dip switch (sw2). This page details and explains the sw2 dip switch. There are 3 switch...

  • Page 35

    Vf boiler service manual aos wpc - tech training 34 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent mcb section h this section of the mcb contains a small “daughter board” that contains the j23 and j24 sockets. Refer to page 25 for more information. The ...

  • Page 36

    Aos wpc - tech training 35 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual pdb - power distribution board - overview the pdb provides connection points for line-input (120 vac) power, the pump, and the transformer. It distributes...

  • Page 37: Tb1

    Vf boiler service manual aos wpc - tech training 36 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent pdb - section a the left side of the pdb circuit board contains a terminal strip (tb1) used to connect the 120 vac power supply to the boiler, the pump re...

  • Page 38

    Aos wpc - tech training 37 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual pdb - section b the mid section of the pdb contains the fusing for the following: f1 fuse - 10 amp 240 vac - european models only † f2 fuse - 20 amp 120 v...

  • Page 39

    Vf boiler service manual aos wpc - tech training 38 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent pdb - section c the upper right corner of the pdb contains the following: j2 socket (24 vac outputs) • pin 1 - 24 vac hot to mcb j3 socket • pin 2 - 24 va...

  • Page 40

    Aos wpc - tech training 39 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent 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 jumper is described o...

  • Page 41

    Vf boiler service manual aos wpc - tech training 40 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent pdb - power supply test the lower right corner of the pdb also contains two jumpers and three power supply status led lights. With power applied the green...

  • Page 42

    Aos wpc - tech training 41 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages - troubleshooting the emc 5000 control system performs exhaustive self diagnostics and displays detected fault conditions on the uim (page ...

  • Page 43

    Vf boiler service manual aos wpc - tech training 42 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages displayed message condition/indicates check/repair uim display is blank boiler is turned off 120 vac power supply problems 24 vac power sup...

  • Page 44

    Aos wpc - tech training 43 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “display fail” communication between the mcb and uim has been interrupted - the m...

  • Page 45

    Vf boiler service manual aos wpc - tech training 44 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “config key crc” data read from the config key by the mcb was not properly confir...

  • Page 46

    Aos wpc - tech training 45 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “low ac voltage” power supply polarity is reversed. Line voltage to boiler is les...

  • Page 47

    Vf boiler service manual aos wpc - tech training 46 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “no flow” pump is not running (if pump is running proceed to the next page) norma...

  • Page 48

    Aos wpc - tech training 47 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “no flow” pump is running (if pump is not running go to the preceding page) norma...

  • Page 49

    Vf boiler service manual aos wpc - tech training 48 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “sequence err” enable/disable circuit wires to vfd disconnected. 1-10 vdc instruc...

  • Page 50

    Aos wpc - tech training 49 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is not starting (if the blower is starting proceed to t...

  • Page 51

    Vf boiler service manual aos wpc - tech training 50 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is not starting (if the blower is starting proceed to t...

  • Page 52

    Aos wpc - tech training 51 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is not starting (if the blower is starting proceed to t...

  • Page 53

    Vf boiler service manual aos wpc - tech training 52 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is starting (if the blower is not starting go to the “b...

  • Page 54

    Aos wpc - tech training 53 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is starting (if the blower is not starting go to the “b...

  • Page 55

    Vf boiler service manual aos wpc - tech training 54 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is starting (if the blower is not starting go to the “b...

  • Page 56

    Aos wpc - tech training 55 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “blower prov stg1” blower is starting (if the blower is not starting go to the “b...

  • Page 57

    Vf boiler service manual aos wpc - tech training 56 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “blocked flue” mcb senses the normally closed blocked flue (exhaust) pressure swi...

  • Page 58

    Aos wpc - tech training 57 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “flame stg1” flame or ignition failure. Error message displayed after 1 or 3 loss...

  • Page 59

    Vf boiler service manual aos wpc - tech training 58 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “flame stg1” (cont) flame or ignition failure. Error message displayed after 1 or...

  • Page 60

    Aos wpc - tech training 59 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual error messages (cont) displayed message condition/indicates check/repair “flame stg1” (cont) flame or ignition failure. Error message displayed after 1 or...

  • Page 61

    Vf boiler service manual aos wpc - tech training 60 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent error messages (cont) displayed message condition/indicates check/repair “igniter stg1” mcb is not sensing minimum igniter current of 2.7 ac amps during t...

  • Page 62

    Aos wpc - tech training 61 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual boiler controls boiler controls that are improperly installed or set up can cause serious operational and service related problems such as short cycling. ...

  • Page 63

    Vf boiler service manual aos wpc - tech training 62 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent boiler controls (cont) primary system control a primary system control is a top level “system” temperature control. A primary system control activates the...

  • Page 64

    Aos wpc - tech training 63 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual boiler controls (cont) controlling probe the operating set point on the vf boiler’s emc 5000 control system reacts to temperature sensed by the controllin...

  • Page 65

    Vf boiler service manual aos wpc - tech training 64 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent boiler controls (cont) internal temperature controls (cont) automatic high limit - user setting “hi limit” the automatic high limit is a “local” emc 5000 ...

  • Page 66

    Aos wpc - tech training 65 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent 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 ...

  • Page 67

    Vf boiler service manual aos wpc - tech training 66 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent boiler controls (cont) external controls (cont) types of external controls an external control can be a primary system control or a supervisory control or...

  • Page 68

    Aos wpc - tech training 67 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual operating temperatures temperature rise through the boiler: 20 - 40°f. The temperature rise ( Δ t = delta t) through the boiler should be maintained betwe...

  • Page 69

    Vf boiler service manual aos wpc - tech training 68 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent technical specifications input power and circuit protection: input specifications: † power supply voltage 120 vac †. See page 40 for pdb power supply test...

  • Page 70

    Aos wpc - tech training 69 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual technical specifications input specifications (cont): † output specifications: † high blower prover pressure switch †. Signal level passed through switche...

  • Page 71

    Vf boiler service manual aos wpc - tech training 70 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent technical specifications ignition timing: default user settings/ranges: as shipped from the factory the sw1 dip switches (page 30) on the mcb are preset t...

  • Page 72

    Aos wpc - tech training 71 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent vf boiler service manual glossary Δ t:symbol used for “delta t.” engineering term to convey “temperature rise” or “difference” through a boiler or heat exchanger. Ie: if the inlet...

  • Page 73

    Vf boiler service manual aos wpc - tech training 72 of 72 ashland city, tn © 2007 servicing should only be performed by a qualified service agent glossary (cont) uim - user interface module:plastic housing that holds the uib, lcd, and tsb. Provides means to both send and receive information from the...

  • Page 74: Variable Fire Boiler

    Variable fire boiler domestic hot water/hydronic heating vf boiler m o d e l s c o v e r e d 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 ©2007 a. O. Smith corporation commercial visit the “information central”...