Takagi Condensing Code 611
Fan motor fault. The combustion fan motor is not behaving as the board expects. That fan supplies combustion air and pushes exhaust through the vent, so nothing burns correctly without it.
Call a proThe verdict
Call a licensed plumber
A real part at a real price, in the combustion air path. Debris in the housing is worth ruling out before the motor is replaced, but that means the unit open with power and gas off.
Typical cost: $250–$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. 13), 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.
- Turn the unit off at the controller and at the breaker.
- Note any rattle or whine you heard before it failed.
- Book a licensed professional.
Frequently asked questions
The fan keeps spinning after the unit stops. Is that this code?
Not by itself — a post-purge run is normal on a sealed-combustion heater, and Takagi's guide treats a fan still spinning after operation as a general question rather than a fault. Code 611 is the board reporting the fan is not doing what it was asked.
Code 611 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:
Don't confuse this with
One other Takagi Condensing code points at a fan too. They are different components in different places, and ordering a part against the wrong one is the most common way this fault gets expensive: