Install Instructions

ManualsBrandsTakagi ManualsCooling & Air QualityT-H2S-OV-NG Tankless Outdoor Water Heater (Natural Gas)

Troubleshooting

43│Page

‐FAULTANALYSISOFERRORCODES‐

Ifthereisaproblemwiththeinstallationofthewaterheater,itwilldisplayanumericalerror

codeonthe

3‐digit7‐Seg.LEDofthecomputerboardortheremotecontroller(ifinstalled)to

communicatethesourceoftheproblem.



Error

Code

Malfunctiondescription Diagnosis

031

Incorrectdipswitchsettings

Check the dipswitch

settingsonPCB

101

Warningforthe“991”errorcode

Call the

manufacturer’s

TechnicalDept.

at1‐877‐737‐2840

111

Ignitionfailure

Checkgassupply

121

Lossofflame

311

Outputthermistorfailure

Call the

manufacturer’s

TechnicalDept.

at1‐877‐737‐2840

321

Inletthermistorfailure

331

Mixingthermistorfailure

341

Exhaustthermistorfailure(DirectVentIndoormodels

only)

391

Air‐fuelRatioRodFailure

441

FlowSensorFailure(OnlyEasy‐Linksystem)

510

AbnormalMainGasValve

551

AbnormalGasSol enoi dValve

611

FanMotorFault

621

Exhaus t fan motor Fault (Direct Vent Indoor models

only)

631

AbnormalExternalPump

651

WaterControlValveFault(FlowAdjustmentfunction)

(OnlyEasy‐Linksystem)

661

WaterControlValveFault(Bypassvalvefunction)

701

ComputerboardFault

711

GasSolenoidValvedrivecircuitfailure

721

FalseFlameDetection

741

Miscommunication between water heater and

remotecontroller

761

Miscommunication in Easy‐Link (520 (T‐H2) models

only)

941

Abnormal exhaust temperature (Direct Vent Indoor

modelsonly)

Lower the set

temperature

991

Imperfectcombustion

Call the

manufacturer’s

TechnicalDept.

at1‐877‐737‐2840