291 🟡 Repair Required

Takagi Error Code 291: Flow Rate Issue

⚠️ 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 — 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.
Type: digital display

What Does Takagi Error Code 291 Mean?

Water flow rate too low — check inlet filter

Common Causes of Takagi Code 291

  • Clogged inlet water filter or strainer — sediment and debris restriction
  • Low incoming water pressure from the municipal supply or well pump
  • Partially closed isolation valve on the cold water inlet
  • Scale buildup inside the heat exchanger reducing flow capacity
  • Flow sensor malfunction or wiring fault giving false low-flow readings

Applicable Takagi Models

T-D2U⚡T-H2S⚡T-H3⚡T-H3J⚡T-H3M⚡T-H3S⚡T-K4⚡T-M32⚡T-M50⚡TK-110U⚡TK-310U⚡TK-510U⚡
🔧

Need a Pro to Fix Takagi Code 291?

A licensed HVAC technician can diagnose and fix this issue quickly.

Find a Licensed Tech Near You →

Replacement Parts for Takagi HVAC System Code 291

Inlet Water Filter Screen OEM: TK-KP05
Flow Sensor OEM: TK-KP09
Heat Exchanger