What It Means
Rollout limit switch open indicating dangerous flame rollout.
Rheem Furnace
Rheem Furnace Error Code 33
Troubleshooting guide for the Rheem Furnace system fault 33.
Possible Causes
- Flame rollout or combustion issue.
- Blocked heat exchanger or vent.
- Damaged heat exchanger.
- Loose wiring or failed safety switch.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
Rollout limit / manually reset limit control open.
All Recorded Causes
Flame rollout or serious combustion/venting problem, blocked heat exchanger or vent, unstable flame, damaged heat exchanger, loose wiring, or bypassed/failed safety switch. Do not run the furnace until inspected.
Verify Before Replacing Parts
- Confirm the exact Rheem model family and furnaces context before acting on a generic code description.
- Walk the entire heating sequence in order instead of jumping straight to the reported code, watching for flame rollout or serious combustion/venting problem, blocked heat exchanger or vent, unsta….
- Verify each safety device and prove where the sequence stops under live operation, including whether do not run the furnace until inspected.
- After the correction, run the system long enough to confirm the furnaces fault does not return under normal load.
Still unsure about this fault?
ACLogics walks you through Rheem Furnace diagnostics step-by-step — so you confirm the cause before swapping parts.
