Takagi Error Code 710: PCB Fault
Warning: The Takagi water heater has detected a problem with its main control board (PCB) and has shut down. This requires troubleshooting to restore hot water.
How to Fix Takagi Code 710
- Step 1: Turn the unit OFF and then back ON using the power switch. This might reset a temporary error.
- Step 2: Check the main electrical panel for tripped breakers. Reset the breaker if necessary.
- Step 3: If the error persists after power cycling and checking the breaker, contact a qualified HVAC technician to diagnose and repair the unit.
How to Reset Takagi Code 710
- Turn off the unit using the power button on the front panel.
- Turn off the gas supply valve.
- Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
- Restore power at the breaker, then open the gas valve.
- Turn the unit back on. If the error returns, the underlying issue needs repair.
What does 710 mean?
The Takagi 710 error code indicates a fault within the Printed Circuit Board (PCB), which is the main control board of your tankless water heater. This board is essentially the 'brain' of the unit, responsible for managing all operations, from monitoring temperature sensors and flow rates to controlling the gas valve and ignition sequence. A fault here means the unit can't reliably control these functions, so it shuts down as a safety measure. The PCB monitors many internal sensors, and the 710 code is a general error that can be triggered by a variety of internal faults. Because the PCB manages so many functions, a 710 error can sometimes be triggered by other failing components.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Main PCB | — | — |
| Wiring Harness | — | — |
| Flame Rod | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 101 | Combustion Abnormality | Critical |
| 111 | Ignition Failure | Critical |
| 121 | Flame Failure | Critical |
| 200 | Overheating | Warning |
| 207 | Bypass Valve Error | Warning |
| 291 | Flow Rate Issue | Warning |
| 312 | Outlet Temp Sensor | Warning |
| 321 | Inlet Temp Sensor | Warning |
| 391 | Exhaust Temp Sensor | Warning |
| 510 | Gas Solenoid Valve | Critical |