Takagi Error Code 291: Flow Rate Issue
Warning: Your Takagi tankless water heater is detecting low water flow. The unit cannot fire safely without adequate flow rate.
How to Fix Takagi Code 291
- Step 1: Locate the cold water inlet filter (usually a small screen at the bottom of the unit) and clean any sediment or debris.
- Step 2: Make sure the cold water isolation valve is fully open u2014 turn counterclockwise until it stops.
- Step 3: Check that other fixtures in the home have normal water pressure. If pressure is low everywhere, the issue may be upstream.
- Step 4: Power-cycle the unit by turning it off, waiting 30 seconds, and turning it back on.
- Step 5: If the error persists, call a plumber or Takagi-certified technician to flush the heat exchanger and test the flow sensor.
How to Reset Takagi Code 291
- 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 291 mean?
Water flow rate too low — check inlet filter
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Inlet Water Filter Screen | TK-KP05 | — |
| Flow Sensor | TK-KP09 | — |
| Heat Exchanger | — | — |
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 |
| 312 | Outlet Temp Sensor | Warning |
| 321 | Inlet Temp Sensor | Warning |
| 391 | Exhaust Temp Sensor | Warning |
| 510 | Gas Solenoid Valve | Critical |
| 610 | Fan Motor Fault | Warning |