Takagi Condensing Code 111
Ignition failure. The heater does not fire after three failed attempts at ignition. Takagi's step one is not the igniter but the hi-limit switch: turn the power off, push the white button in until it clicks, then power back on. Its list continues through gas supply and pressure, a plastic tube between the proportional gas valve and the combustion chamber, the overheat cutoff fuse, a dirty flame sensor, the igniter spark, and vent blockages.
Call a proThe verdict
Call a licensed plumber
Confirm gas is reaching the house — that part is yours. Everything else on Takagi's list is inside the cabinet of a gas appliance, and note what Takagi says about the hi-limit: if resetting it makes the unit fire, the reason it tripped still has to be found.
Typical cost: $150–$900
US estimate for parts and labor. Prices vary by region and by who does the work — see how we estimate costs.
What the manual says
The meaning above is transcribed from the manufacturer's diagnostic documentation for the Condensing — not averaged across the brand.
Source: Takagi Condensing Models On-Demand Water Heater Troubleshooting Guide (p. 15), read Aug 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
Before anything else: if you smell gas, stop here, leave, and call your gas utility.
- If you smell gas, leave the building and call your gas utility from outside.
- Check that other gas appliances in the house work.
- On propane, check the tank level — Takagi notes cold weather can chill the regulator and cause this.
- Do not open the front panel to reset the hi-limit switch or inspect the igniter.
- Book a licensed professional.
Frequently asked questions
Takagi says to reset the hi-limit switch. Should I?
That is written for a technician with the cover off a gas appliance. And read the rest of what Takagi says about it: if the unit fires after the reset, the cause of the trip must still be determined and their technical service contacted. A hi-limit that trips is reporting a real overheat.
It flames for one or two seconds then stops.
Takagi treats that as a specific symptom on this code and points at cleaning the flame sensor. It means ignition is working and flame detection is not.
Code 111 on other Takagi series
The same code number can mean something different on another series — make sure you're reading the page for your exact unit: