Rheem furnace Which blink code list applies: Rheem publishes two blink code lists that contradict each other

Rheem's standard gas furnace flash code list and the sequence-of-operation blink codes in the *RC 92+ and *RL 90+ installation instructions disagree on three of the first four counts. Counting blinks on a Rheem is not enough — you have to know which control you are looking at.

Applies to: Rheem, Ruud and Weather King gas furnaces. Read this before acting on any Rheem blink count, because the same count means different things on different Rheem platforms.

What it means

Rheem publishes a short list of diagnostic flash codes on its technical support site, and states plainly at the top that it does not cover modulating, LXE or two-stage furnaces. Separately, the installation instructions for the *RC 92+ upflow and *RL 90+ downflow condensing furnaces describe blink codes inside the sequence of operation rather than in a table. The two do not agree. On the standard list one blink is a one-hour soft lockout, three blinks is an open limit switch, and four blinks is a pressure switch stuck closed. On the condensing furnace instructions one blink is an open limit circuit, three blinks is a pressure switch stuck closed, and four blinks is lockout after five failed ignition attempts. Only two blinks means the same thing on both — a pressure switch that will not close. This is not a contradiction in the documents so much as two different control platforms sold under one brand, but the practical effect is the same: a count read off the wrong list produces the wrong repair.

Most common causes

The two lists come from different control platforms, not from an error in either document.
Rheem's standard flash code page explicitly excludes modulating, LXE and two-stage furnaces from its scope.
The *RC 92+ and *RL 90+ instructions describe their codes in the sequence of operation rather than in a labelled table, so they are easy to miss.
Rheem, Ruud and Weather King are the same equipment under different names, so the ambiguity carries across all three.

How to diagnose it

Find the model number on the rating plate inside the furnace cabinet before counting anything.
A model beginning RC or RL, or described as a 92+ or 90+ condensing furnace, points at the condensing instructions list.
If the furnace is modulating, two-stage, or an LXE model, the standard flash code list does not apply to it at all — Rheem says so directly.
If the model cannot be identified, treat a blink count as ambiguous rather than guessing, and have a technician confirm against the documentation for that specific unit.

How to fix it

There is nothing to fix here. This page exists so a count is not acted on against the wrong list.
Once the platform is identified, follow the matching page on this site.
If the two readings suggest different faults and the model is unclear, the safer of the two interpretations is the one to act on first.

Notes

This is the second manufacturer on this site with the same problem. Heil, Tempstar and Comfortmaker have it too, for a different reason — one of their documents describes the control board and the other a Honeywell SmartValve. In both cases the failure mode for a reader is identical: a confident answer from the wrong table.

All codes for this manufacturer

Rheem, Ruud and Weather King furnace blink codes — every code, with what differs between models.

Sources

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.