Takagi Error Code 101: Combustion Abnormality

Severity
Critical
Type
digital display
Estimated repair cost: $100 — $350 (parts + labor)
Warning: This error indicates a problem with the combustion process, which could lead to a dangerous buildup of carbon monoxide. Shut down the unit immediately and call a qualified technician.

How to Fix Takagi Code 101

  1. Step 1: Ensure all gas appliances are working correctly. If other gas appliances aren't working, there may be a gas supply problem.
  2. Step 2: Check the venting for any obvious obstructions like leaves, snow, or debris. Clear any blockages you can safely reach from the ground.
  3. Step 3: Contact a qualified HVAC technician or plumber to inspect the unit and diagnose the problem. Do not attempt to repair the unit yourself.

How to Reset Takagi Code 101

  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 101 mean?

The Takagi error code 101, 'Combustion Abnormality,' means the unit's control board isn't seeing the expected flame signal during operation. This can happen for a few reasons, but it always points to a problem in the burner or venting system. The unit is designed to shut down as a safety measure when this happens to prevent the uncontrolled release of gas or the production of dangerous levels of carbon monoxide.

When this error occurs, the water heater will likely lock out, meaning it won't attempt to restart until the issue is resolved and the error is cleared. Continuing to try and run the unit without addressing the underlying problem is unsafe. A qualified technician needs to diagnose the root cause and make the necessary repairs to ensure safe and reliable operation.

Affected Models

Replacement Parts

PartOEM NumberEst. Cost
Flame Rod — —
Gas Valve — —
Igniter — —

Related Codes on Same Models

CodeDescriptionSeverity
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
610 Fan Motor Fault Warning