Takagi Error Code 291: Flow Rate Issue

Severity
Warning
Type
digital display
Estimated repair cost: $100 — $350 (parts + labor)
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

  1. Step 1: Locate the cold water inlet filter (usually a small screen at the bottom of the unit) and clean any sediment or debris.
  2. Step 2: Make sure the cold water isolation valve is fully open u2014 turn counterclockwise until it stops.
  3. Step 3: Check that other fixtures in the home have normal water pressure. If pressure is low everywhere, the issue may be upstream.
  4. Step 4: Power-cycle the unit by turning it off, waiting 30 seconds, and turning it back on.
  5. 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

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. 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

PartOEM NumberEst. Cost
Inlet Water Filter Screen TK-KP05
Flow Sensor TK-KP09
Heat Exchanger

Related Codes on Same Models

CodeDescriptionSeverity
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