Rheem Error Codes & Diagnostics
Complete diagnostic directory for official Rheem fault codes. Verify root causes, safe troubleshooting steps, and replacement part numbers before calling a technician.
Rheem furnace one-blink lockout: four trials or four flame failures
Rheem publishes the one-blink code as no flame sensed after four ignition trials, or four flame failures during one call for heat. Those are two different histories: in the first the burner never established a flame, and in the second it lit four times and the signal was lost each time. To clear it, Rheem has the owner interrupt the 115 volt supply, or switch the thermostat off, for a count of five to ten seconds. Applies to: Rheem residential gas furnaces covered by the published technical FAQ This code and reset method come from Rheem's published gas furnace technical FAQ and apply to the Rheem furnaces it covers. Ruud furnaces share much of the Rheem platform but their own literature governs, and a single flash on another manufacturer's control means something else entirely. Owner-safe checks: Stand where you can hear the furnace and note whether the burner is audible on each attempt before the lockout. | Count the blinks and confirm the pattern repeats rather than changing between cycles. | Check that other gas appliances in the house work, without operating a valve or opening the furnace cabinet. | Confirm the filter is clean and every supply register is open, since airflow faults produce a different code. | Clear the lockout once, by interrupting the 115 volt supply or the thermostat for a count of five to ten seconds. Qualified technician: The same lockout returning after one reset with the gas supply confirmed. | A two-blink or four-blink pressure-switch pattern, which is a separate combustion-safety service path. | Any work on the flame sense rod, gas valve, or manifold pressure, all of which need the burner compartment opened. | Suspected supply polarity or grounding problems, which are electrical rather than heating work. | Any smell of gas, which is an evacuation and an emergency call rather than a service request.
Rheem two blinks: the draft proving circuit stopped the sequence
Two blinks on a Rheem furnace control identifies a pressure switch condition in the draft proving circuit. The switch is the device that tells the control whether the inducer has established the airflow the burner needs, so the blink count locates the circuit that failed to reach its expected state rather than the part that caused it. Applies to: Rheem R96V modulating condensing gas furnaces documented in the Rheem service literature This reading follows the diagnostic table published for the Rheem R96V modulating condensing furnace. Rheem and Ruud have used different blink assignments across control generations, and a chart written for another Rheem furnace line can give a different meaning for the same count. Match the model on the rating plate. Owner-safe checks: Count the blinks carefully, since two blinks and three blinks are easy to confuse when the pause between groups is short. | View the vent and intake terminations from ground level and note ice, snow, nests, or vegetation without climbing or reaching in. | Record the outdoor temperature, wind, and whether ignition was ever attempted on each failed cycle. Qualified technician: Measuring draft pressure against the published value, inspecting the inducer wheel, and clearing condensate paths are licensed gas-furnace tasks. | A pressure switch must never be bridged or bypassed to make a furnace run, because it is the only device confirming that combustion products are leaving the building.
Rheem R96V fault 57: pressure switch open at the wrong time
Rheem R96V fault 57 means the combustion pressure switch is open when the control expects it closed. The furnace can withhold gas heat while other modes remain available. The code does not prove a defective switch because draft, venting, condensate, tubing, inducer, wiring, and actual pressure determine its state. Applies to: R96V communicating condensing gas furnaces This definition applies to R96V furnaces covered by Rheem document 92-24161-184. Other Rheem control generations and water-heating products can assign 57 differently, so use the full furnace model. Owner-safe checks: With panels intact, capture code 57, thermostat demand, inducer sound, time to fault, and safe exterior photos of the vent termination. Qualified technician: Draft measurement, vent and condensate access, inducer testing, tubing inspection, switch verification, wiring, and combustion work require licensed furnace service.
Rheem EcoNet A006_C outdoor unit communication failure: why a breaker reset holds for a while
The alarm reports that the control is no longer hearing the outdoor unit, which is a statement about the path between them rather than about the outdoor unit itself. Cutting power at the breaker forces the whole network to start again, so a marginal connection that had drifted out of tolerance gets one more chance to work. That is why the system runs afterwards, and it is also why nothing about the restart tells you the connection has been repaired. Applies to: Rheem and Ruud EcoNet communicating systems in which a smart thermostat or control center shares a four-wire network with indoor and outdoor equipment EcoNet is a wired communicating network, and this page describes the network requirements published for Rheem and Ruud EcoNet controls. It does not cover Rheem equipment running on a conventional 24 volt thermostat, where no equivalent alarm exists. Owner-safe checks: Photograph the alarm history and the current alarm screen before interrupting power, because a restart clears the active entry. | Record the outdoor temperature and the time at each occurrence so a repeatable trigger becomes visible. | Note whether the indoor section kept running, which separates a whole-network problem from an outdoor one. Qualified technician: Inspecting the network run for a star branch, and checking terminations at each device, means opening equipment enclosures and is qualified service work. | Measuring supply voltage at a communicating device under load is an energised measurement for a technician.