Ruud Error Codes & Diagnostics
Complete diagnostic directory for official Ruud fault codes. Verify root causes, safe troubleshooting steps, and replacement part numbers before calling a technician.
Ruud R96T fault 58: open water-sensor circuit
On the documented Ruud R96T, fault 58 means the water-sensor circuit is open. Depending on the installed configuration, that path can include a water sensor or a required jumper plus its wiring and control input. It is not the same as the combustion pressure-switch codes and does not prove water is present. Applies to: R96T two-stage communicating condensing furnaces This definition is limited to the R96T manual cited here. Rheem and Ruud share some platforms, but model suffix, control generation, optional sensor configuration, and the exact code table still govern the diagnosis. Owner-safe checks: Keep panels closed, photograph fault 58 and the rating plate, and observe only external water or recent drain work from a safe position. Qualified technician: Configuration verification, sensor and jumper access, continuity tests, condensate diagnosis, wiring repair, and control-input checks require qualified furnace service.
Ruud blink codes: counting correctly is most of the diagnosis
A Ruud furnace control reports its diagnosis as a number of blinks separated by pauses, and the number is the whole message. Two blinks and three blinks describe different conditions, the pause between groups is easy to miss, and a miscount sends the whole diagnosis somewhere it does not belong. Applies to: Ruud gas furnaces whose integrated controls report diagnostics through a blinking indicator, including the R96T range Blink assignments belong to a control platform rather than to the Ruud name, and they have differed across furnace ranges and generations. The diagnostic label inside the furnace door, and the installation instructions for the model on the rating plate, are the reference for what a given count means. Owner-safe checks: Record a video through the door sight glass across several full repetitions rather than counting by eye. | Keep the blower door closed, since opening it can remove control power and clear the indication. | Write the count down immediately with the date and time, and note whether it has changed between attempts. Qualified technician: Interpreting a count against the diagnostic label, testing components, and any work inside the furnace cabinet are licensed gas-furnace tasks. | A count corresponding to a limit, a rollout, or a flame condition is a stop condition rather than something to observe across further cycles.