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Takagi T-H3-DV Service Handbook

Manual is about: Condensing Models

Summary of T-H3-DV

  • Page 1

    Condensing models on-demand water heater service handbook dir 2000534342 rev. A october 2016 models: 240 indoor (t-h3j-dv) 240 outdoor (t-h3j-os) 340 indoor (t-h3s-dv) 340 outdoor (t-h3s-os) 540 indoor (t-h3-dv) 540 outdoor (t-h3-os) this service handbook is for use by qualified service professional...

  • Page 2: Table Of Contents

    2 • on-demand water heater service handbook for 240, 340 & 540 condensing models table of contents specifications .............................................................................................................................................................................................

  • Page 3

    On-demand water heater service handbook for 240, 340 & 540 condensing models • 3 service procedures ................................................................................................................................................................................32 unit draining and fil...

  • Page 4: Basics

    Basics basics basics basics 4 • on-demand water heater service handbook for 240, 340 & 540 condensing models specifications table 1: model 240 indoor (t-h3j-dv) 240 outdoor (t-h3j-os) 340 indoor (t-h3s-dv) 340 outdoor (t-h3s-os) 540 indoor (t-h3-dv) 540 outdoor (t-h3-os) natural gas input (operating...

  • Page 5: Basics

    Basics basics on-demand water heater service handbook for 240, 340 & 540 condensing models • 5 basics basics introduction read and follow all safety messages and instructions in this handbook and on the product labeling. This is the safety alert symbol. It is used to alert you to potential physical ...

  • Page 6: Basics

    Basics 6 • on-demand water heater service handbook for 240, 340 & 540 condensing models if any problem occurs, turn off all hot water taps and turn off the gas. Then call a trained technician or the gas company. Becoming familiar with how a tankless water heater normally operates may help to trouble...

  • Page 7: Ouble

    On-demand water heater service handbook for 240, 340 & 540 condensing models • 7 tr ouble shoo ting remote controller: if you are using a remote controller, the remote’s power button must be turned on. Press the power button on the remote until the amber stand-by led is lit. High altitude: if the he...

  • Page 8: Ouble

    Tr ouble shoo ting tr ouble shoo ting 8 • on-demand water heater service handbook for 240, 340 & 540 condensing models next step: finally, check to see if the unit has an error code. The error code will be displayed on the temperature controller (or remote controller) and by flash codes on the green...

  • Page 9: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 9 reading correctly. Refer to error codes 311 and 321 in table 2: error and flash codes, page 11. • the flow adjustment valve could be obstructed due to hard water scale or debris, ca...

  • Page 10: Ouble

    Tr ouble shoo ting tr ouble shoo ting tr ouble shoo ting tr ouble shoo ting 10 • on-demand water heater service handbook for 240, 340 & 540 condensing models unit does not ignite when water goes through it. • if you have an indoor model, is the power button on the built-in controller turned on? • if...

  • Page 11: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 11 tr ouble shoo ting tr ouble shoo ting error codes all units have self-diagnostics. If there is a problem with the unit, a numerical error code will display on the temperature contr...

  • Page 12: Ouble

    Tr ouble shoo ting tr ouble shoo ting tr ouble shoo ting 12 • on-demand water heater service handbook for 240, 340 & 540 condensing models error code green led on computer board symptom or issue troubleshooting procedure (page number) 321 two flashes inlet thermistor failure code 311, 321, 331 or 34...

  • Page 13: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 13 error code green led on computer board symptom or issue troubleshooting procedure (page number) 941 five flashes abnormal exhaust temperature (indoor model only) code 941: abnormal...

  • Page 14: Ouble

    Tr ouble shoo ting tr ouble shoo ting 14 • on-demand water heater service handbook for 240, 340 & 540 condensing models code 031: incorrect dip switch settings the system displays this code when an incorrect dip switch setting is detected. 1. Turn off the power supply. 2. Remove front cover and loca...

  • Page 15: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 15 2.3.1 push the button in the middle of it. The switch was reset if you heard and felt the button click. 2.3.2 turn the power back on and test the heater. If the burner lights, the ...

  • Page 16: Ouble

    Tr ouble shoo ting tr ouble shoo ting 16 • on-demand water heater service handbook for 240, 340 & 540 condensing models error code indoor or outdoor model? Model type locate the thermistor by its callout: 311 indoor or outdoor 540 see “heat exchanger thermistor” page 49. 321 indoor or outdoor 240 34...

  • Page 17: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 17 allow you to access the outlet thermistor. C. Remove the screw or clip that secures the thermistor, then pull the sensor probe out. D. Clean the probe to a silver finish. Do not lo...

  • Page 18: Ouble

    Tr ouble shoo ting tr ouble shoo ting 18 • on-demand water heater service handbook for 240, 340 & 540 condensing models replace the gas valve. 6. Check the voltage across the main gas valve wires (blue - light blue #3) during operation. The voltage reading should be 93-120 vdc. If the voltage is not...

  • Page 19: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 19 the black and red wires. (see page 30 or 31.) normal voltage range (black-red): 7 vdc - 16 vdc. If the voltage is out of range, replace the computer board. (see page 49 or 50.) cod...

  • Page 20: Ouble

    Tr ouble shoo ting tr ouble shoo ting 20 • on-demand water heater service handbook for 240, 340 & 540 condensing models page 35. 5. There may be a computer board (pcb) and/or gas valve fault. Refer to error codes 510 and 551. Code 721: false flame detection a false flame was detected by the system d...

  • Page 21: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 21 • multi-link system: push the alarm reset button on the multi-unit controller to clear the code. Code 941: abnormal exhaust temperature (indoor models only.) this code indicates th...

  • Page 22: Ouble

    Tr ouble shoo ting tr ouble shoo ting tr ouble shoo ting tr ouble shoo ting 22 • on-demand water heater service handbook for 240, 340 & 540 condensing models for the correct volume of gas. Refer to the installation manual or the current edition of the national fuel gas code, ansi z223.1/ nfpa 54 (u....

  • Page 23: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 23 tr ouble shoo ting tr ouble shoo ting dip switch settings the computer board layout for all 240 and 340 models is identical. See “wiring diagrams,” page 30. The dip switches have c...

  • Page 24: Ouble

    Tr ouble shoo ting tr ouble shoo ting 24 • on-demand water heater service handbook for 240, 340 & 540 condensing models the 540 indoor (t-h3-dv) model uses the same computer board as the 540 outdoor (t-h3-os) model. There are two banks of dip switches (upper and lower bank) on the computer board. Th...

  • Page 25: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 25 dip switch settings (continued) table 7: 540 (t-h3) model lower bank of dip switches (figure 11) note: dark squares represents dip switches lower bank of dip switches : 540 (t-h3) ...

  • Page 26: Ouble

    Tr ouble shoo ting tr ouble shoo ting 26 • on-demand water heater service handbook for 240, 340 & 540 condensing models high altitude settings elevation level dip switch settings output reduction fan motor speed change no.3 no.4 no.5 0 to 2,000 ft. 0(default) off off off n/a n/a 2,000 to 3,000 ft. 1...

  • Page 27: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 27 high altitude settings (continued) figure 13 : 240 (t-h3j) and 340 (t-h3s) bank of dip switches table 10: outdoor model, 240 (t-h3j) / 340 (t-h3s) - propane apply the altitude sett...

  • Page 28: Ouble

    Tr ouble shoo ting tr ouble shoo ting 28 • on-demand water heater service handbook for 240, 340 & 540 condensing models high altitude settings (continued) elevation level dip switch settings output reduction fan motor speed change no.2 no.3 no.4 0 to 2,000 ft. 0(default) off off off n/a n/a 2,000 to...

  • Page 29: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 29 * **these settings are not listed in the 240(t-h3j),340(t-h3s), and 540(t-h3) installation manual. High altitude settings (continued) elevation level dip switch settings output red...

  • Page 30: Ouble

    Tr ouble shoo ting tr ouble shoo ting 30 • on-demand water heater service handbook for 240, 340 & 540 condensing models wiring diagrams continued on the next page. Figure 15: wiring schematic for 240 (t-h3j) and 340 (t-h3s) models w: white r: red bk: black p: purple lb: light blue bl: blue g: green ...

  • Page 31: Ouble

    Tr ouble shoo ting tr ouble shoo ting on-demand water heater service handbook for 240, 340 & 540 condensing models • 31 wiring diagrams (continued) w: white r: red bk: black p: purple lb: light blue bl: blue g: green y: yellow o: orange br: brown 8 7 6 5 4 3 2 1 on 6 5 4 3 2 1 on r w g y pcb w 120 v...

  • Page 32: Ser

    Ser vice pr ocedure s ser vice pr ocedure s 32 • on-demand water heater service handbook for 240, 340 & 540 condensing models service procedures unit draining and filter cleaning warning water drained from the water heater may be hot and could cause severe burns. Failure to observe proper safety pra...

  • Page 33: Ser

    Ser vice pr ocedure s ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 33 the pressure-relief valve, the system has a reversed connection. Checking the inlet gas pressure and pressure drop this test is most effective when all gas appliances on the ...

  • Page 34: Ser

    Ser vice pr ocedure s ser vice pr ocedure s 34 • on-demand water heater service handbook for 240, 340 & 540 condensing models 12. The gas supply pressures should be within the following ranges: • natural gas: 4 to 10.5 inches w.C. • propane: 8 to 14.0 inches w.C. 13. Subtract your static supply gas ...

  • Page 35: Ser

    Ser vice pr ocedure s ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 35 match up with those listed on the rating plate, adjust the manifold pressure. To do so, refer to the following procedures. Adjusting maximum manifold pressure warning! Comple...

  • Page 36: Ser

    Ser vice pr ocedure s ser vice pr ocedure s 36 • on-demand water heater service handbook for 240, 340 & 540 condensing models 49 or figure 42, p. 50. 3. Find the white clip at the end of the two blue braided wires coming from the ohcf. (refer to figure 23 on page 35.) 4. Unplug the connection. 5. Te...

  • Page 37: Ser

    Ser vice pr ocedure s ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 37 conductive spade. To release the afr rod connector, follow the instructions in figure 25. 3.3 remove the three phillips- head screws holding the panel in place. 3.4 pull the ...

  • Page 38: Ser

    Ser vice pr ocedure s ser vice pr ocedure s 38 • on-demand water heater service handbook for 240, 340 & 540 condensing models descaling the unit during operation, a tankless water heater accumulates hard water deposits on the interior surfaces of the heat exchanger. These deposits make it difficult ...

  • Page 39: Ser

    Ser vice pr ocedure s ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 39 cleaning the combustion components follow these procedures to clean the fan, burner, flame sensor and air/fuel ratio rod (afr). Tools and materials ● degreaser in a pump acti...

  • Page 40: Ser

    Ser vice pr ocedure s ser vice pr ocedure s 40 • on-demand water heater service handbook for 240, 340 & 540 condensing models notice: remove only the screws along the outside edges of the manifold plate. See figure 28. • do not remove the screws securing the manifold plate to the gas valve. • notice...

  • Page 41: Ser

    Ser vice pr ocedure s ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 41 6.2.4 once loosened, grasp an oval air vent in the center and pull the burner out. Brace the bottom of the combustion chamber to provide leverage. 6.3 inspect the gasket. Min...

  • Page 42: Ser

    Ser vice pr ocedure s ser vice pr ocedure s ser vice pr ocedure s ser vice pr ocedure s 42 • on-demand water heater service handbook for 240, 340 & 540 condensing models 9.2 insert an air compressor’s air hose into the opening from which the burner was removed. ◦ blow air up into the heat exchanger ...

  • Page 43: Ser

    Ser vice pr ocedure s ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 43 ser vice pr ocedure s ser vice pr ocedure s easy-link connections with previous models (540 [t-h3] only) dip switch setting on the 540 (t-h3) computer board the 540 (t-h3) mo...

  • Page 44: Ser

    Ser vice pr ocedure s 44 • on-demand water heater service handbook for 240, 340 & 540 condensing models temperature settings when the 540 (t-h3) is connected with 520 (t-h2) models as part of an easy-link system, the available set temperatures will default to what is available on the 520 (t-h2). The...

  • Page 45: Ser

    Ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 45 diagnostic mode diagnostic mode allows you to discover various pieces of information about one or more water heaters, even if they are linked together through an easy-link or multi-unit system. In...

  • Page 46: Ser

    Ser vice pr ocedure s 46 • on-demand water heater service handbook for 240, 340 & 540 condensing models 2. “0” will display on the controller. (figure 40.) 3. Scroll to the desired 540 (t-h3) unit number in the linked system by pressing the hot or cold button to scroll up or down. (figure 40 shows t...

  • Page 47: Ser

    Ser vice pr ocedure s on-demand water heater service handbook for 240, 340 & 540 condensing models • 47 table 18. Mode # whole multi-unit system information (#0) unit information (#1 to #4) 1 total system flow rate 0 to 999 (gpm) total operation time 0 to 999 (x 100 hours) 2 btu requirement for the m...

  • Page 48: Ser

    Ser vice pr ocedure s 48 • on-demand water heater service handbook for 240, 340 & 540 condensing models this page is left blank to preserve facing pages..

  • Page 49: Maintenance

    Maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 49 maintenance indoor model (front view/cabinet interior): ground connection pipe heater/block heater condensate drain tube three screws secure the secondary heat exchanger to the case high limit switch (heat ...

  • Page 50: Maintenance

    Maintenance 50 • on-demand water heater service handbook for 240, 340 & 540 condensing models outlet thermistor (behind pcb) outdoor model (front view/cabinet interior): note: 540 outdoor models include a heat exchanger thermistor and a bypass valve which are not shown in this graphic. However, thei...

  • Page 51: Maintenance

    Maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 51 flow sensor/ control valve removal and installation tools: #2 phillips screw driver see also “checking the flow sensor,” page 36. Removal 1. Shut off power by disconnecting the power cord or shutting off th...

  • Page 52: Maintenance

    Maintenance maintenance 52 • on-demand water heater service handbook for 240, 340 & 540 condensing models burner removal and installation tools: ● #2 phillips screw driver notice: as you complete the following steps, reinstall the screws after removing each component. Doing so will keep the fastener...

  • Page 53: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 53 • notice: do not remove the screws along the interior of the manifold plate. 5.3 indoor models: remove the power cord mounting tab. (figure 41, page 49.) 5.4 disconnect the clear air tube off th...

  • Page 54: Maintenance

    Maintenance maintenance 54 • on-demand water heater service handbook for 240, 340 & 540 condensing models 6.4 inspect the gasket. Minor surface tears are acceptable. If the gasket shows major separations, replace the gasket before the unit is returned to service. (the parts list starts on page 75; b...

  • Page 55: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 55 5. Install the fuse box assembly to the left side of the manifold plate. (see figure 41 (p. 49) or figure 42 (p. 50).) hand tighten two screws to secure it to the manifold plate. 6. Install the ...

  • Page 56: Maintenance

    Maintenance maintenance 56 • on-demand water heater service handbook for 240, 340 & 540 condensing models fasteners organized and will expedite reassembly. Warning □ disconnect power to the water heater by unplugging it from the wall outlet or turning it off at the circuit breaker, as appropriate. □...

  • Page 57: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 57 5.4 disconnect the clear air tube off the left side of the gas valve. (figure 49.) 5.5 remove the screw securing the gas valve to the gas inlet connection. • the screw is located at the bottom, ...

  • Page 58: Maintenance

    Maintenance maintenance 58 • on-demand water heater service handbook for 240, 340 & 540 condensing models 6.4 secure the gas valve to the inlet by installing the brass screw through both tabs at the connection (hand-tight only). See figure 41 (p. 49) or figure 42 (p. 50). 6.5 attach the air tube fro...

  • Page 59: Maintenance

    Maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 59 maintenance maintenance this page is left blank to preserve facing pages..

  • Page 60: Maintenance

    Maintenance maintenance 60 • on-demand water heater service handbook for 240, 340 & 540 condensing models replacing the heat exchanger tools: ● #2 phillips screw driver, 8” long (a magnetic tip is helpful) ● pliers warning □ disconnect power by opening the circuit breaker or removing the fuses befor...

  • Page 61: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 61 4.1 open the clip that secures the yellow wires to the bottom, left-hand side of the cabinet. Remove the wires. See figure 52. 4.2 remove both screws that secure the fuse box and lift the fuse b...

  • Page 62: Maintenance

    Maintenance maintenance 62 • on-demand water heater service handbook for 240, 340 & 540 condensing models flame rod wire connector: to remove, pinch flat sides at end with your finger nails, then slide connector off the spade. Figure 55. The wires are locked onto the connectors. Pinch the flat sides...

  • Page 63: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 63 9.11 inspect the o-ring (item 151, p. 73) and gas inlet ring (item 119, p. 73) at the gas inlet for cuts or breaks. If damaged, replace with part number 100074242 (item 151) and/or 100074526 (it...

  • Page 64: Maintenance

    Maintenance maintenance 64 • on-demand water heater service handbook for 240, 340 & 540 condensing models figure 63. Three screws securing the secondary heat exchanger 12. Disconnect and remove the following items: 12.1 disconnect the condensate drain line (item 416, page 74) from the secondary heat...

  • Page 65: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 65 13.2.3 remove the eight screws that hold the primary and secondary heat exchangers together. (there are two screws on each of the four sides. Save them for future use.) notice: the primary and s...

  • Page 66: Maintenance

    Maintenance maintenance 66 • on-demand water heater service handbook for 240, 340 & 540 condensing models exhaust flue. • exhaust thermistor, gasket, bracket, and screw. (see items 471, 718, 470, and 053 on page 74.) • exhaust high limit switch (item 472, page 74): it can be removed and installed by...

  • Page 67: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 67 8. Reconnect the drain pipe (item 465) as shown in the diagram on page 74. Secure both ends with 6-15 clips. 9. Slide the burner into the combustion chamber. (see figure 66.) there are grooves o...

  • Page 68: Maintenance

    Maintenance maintenance 68 • on-demand water heater service handbook for 240, 340 & 540 condensing models 16.2 slide the black igniter wire onto the igniter rod. See “igniter rod wire connection” in figure 41, page 49. 17. Install the flow sensor/control valve (item 402, p. 74) and cold pipe (item 4...

  • Page 69: Maintenance

    Maintenance maintenance on-demand water heater service handbook for 240, 340 & 540 condensing models • 69 17.2 insert the end of the cold pipe into the outlet of the flow sensor/control valve. See connection point “d” on page 74 (shown in two places). 17.3 install these fasteners: • one 16a fastener...

  • Page 70: Maintenance

    Maintenance 70 • on-demand water heater service handbook for 240, 340 & 540 condensing models • plug both spade connectors (blue wires) onto the heat exchanger’s high limit switch. See “high limit switch (heat exchanger)” in figure 41 (p. 49) or figure 42 (p. 50). • reconnect the flame rod and afr w...

  • Page 71: Component

    Component s on-demand water heater service handbook for 240, 340 & 540 condensing models • 71 component diagrams/item numbers indoor model outdoor model case assembly 052 052 003 007 002 050 006 704 005 052 702 704 008 052 050 052 717 702 713 004 002 001 001 004 temperature remote controller 724 723...

  • Page 72: Component

    Component s component s 72 • on-demand water heater service handbook for 240, 340 & 540 condensing models component diagrams/item numbers (cont.) computer board assembly surge box assembly 540 (t-h3) model 240 (t-h3j) and 340 (t-h3s) model 710 701 713 103 709 402 707 708 714 721 407 408 701 714 403 ...

  • Page 73: Component

    Component s component s on-demand water heater service handbook for 240, 340 & 540 condensing models • 73 component diagrams/item numbers (cont.) burner assembly 101 104 115 106 107 108 110 109 111 712 112 062 053 053 709 053 401 103 105 065 054 113 114 102 708 119 151 118 055 051 150 057 055 063 11...

  • Page 74: Component

    Component s component s component s component s 74 • on-demand water heater service handbook for 240, 340 & 540 condensing models component diagrams/item numbers (cont.) 402 460 456 461 458 404 417 407 454 405 457 406 410 455 408 458 454 462 c d 052 059 052 409 417 water outlet section water inlet s...

  • Page 75: Component

    Component s component s on-demand water heater service handbook for 240, 340 & 540 condensing models • 75 component s component s component item numbers item # part # description 240, 340, and 540 models t-h3j, t-h3s and t-h3 models 001 n/a ek159 case assembly for indoor model n/a ek164 case assembl...

  • Page 76: Component

    Component s component s 76 • on-demand water heater service handbook for 240, 340 & 540 condensing models component item numbers (cont.) item # part # description 240, 340, and 540 models t-h3j, t-h3s and t-h3 models 103 100074606 ek109 fan motor for indoor models 100074228 ekk25 fan motor for outdo...

  • Page 77: Component

    Component s component s on-demand water heater service handbook for 240, 340 & 540 condensing models • 77 component item numbers (cont.) item # part # description 240, 340, and 540 models t-h3j, t-h3s and t-h3 models 407 100074398 ekk4j inlet thermistor for 240 (t-h3j) and 340 (t-h3s) models 1000746...

  • Page 78: Component

    Component s component s 78 • on-demand water heater service handbook for 240, 340 & 540 condensing models component item numbers (cont.) item # part # description 240, 340, and 540 models t-h3j, t-h3s and t-h3 models 466 100074688 ek219 cold pipe for 240 (t-h3j) and 340 (t-h3s) models 100074689 ek22...

  • Page 79: Component

    Component s component s on-demand water heater service handbook for 240, 340 & 540 condensing models • 79 component item numbers (cont.) item # part # description 240, 340, and 540 models t-h3j, t-h3s and t-h3 models 723 n/a ek178 fixing plate 724 100112572 tm-re40 temperature remote controller 1002...

  • Page 80

    80 • on-demand water heater service handbook for 240, 340 & 540 condensing models copyright © 2016 a.O. Smith corporation. All rights reserved..