Takagi Condensing Code 941
Abnormal exhaust temperature. The exhaust temperature is outside the range Takagi expects. On a condensing unit the flue is supposed to run cool — that is where the efficiency comes from — so an abnormal reading usually means heat is not crossing into the water, and scale in the heat exchanger is the classic reason.
Call a proThe verdict
Call a licensed plumber
Treat it as a professional visit rather than a DIY flush: restricted venting produces the same reading, and once a heat exchanger has been running hot it deserves inspecting rather than just descaling.
Typical cost: $150–$1,400
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.
- Stop using the unit and leave it off until it is checked.
- Note when it was last flushed and whether your water is hard.
- Check the vent terminal outside for obstructions.
- Book a licensed professional.
Frequently asked questions
How is 941 different from 341?
941 says the exhaust temperature itself is abnormal. 341 says the sensor measuring it has failed. The first is a real condition, the second is a broken instrument.