Takagi uses direct spark ignition. When the igniter fails, the unit throws Code 111.
Confirm igniter failure
- Turn off gas
- Trigger ignition attempt by opening hot tap
- In dark room, look through sight glass
- Bright blue spark = igniter OK
- No spark = igniter or cable failed
Replacement (DIY)
- Power off and shut off gas
- Remove front cover
- Locate igniter (ceramic-encapsulated probe with high-voltage cable)
- Disconnect cable from PCB; unscrew igniter
- Install new igniter; reconnect
- Restore gas, power on, test
Cost
OEM Takagi igniter: $50-100. OEM-equivalent: $20-60.
Bottom line
Visual confirmation before ordering. Replacement is straightforward DIY.