Frymaster M3000 Fryer Error Code E13: Return Valve Not Closed
ERROR RETURN VALVE NOT CLOSED (E13) on a Frymaster Gen II LOV fryer with the M3000 computer means the return valve failed to close and its position is unknown. The manual says to call service. Check the vat and the pan for oil that is in the wrong place.
Medium: oil may move between pan and vat, so filtering is unreliable, but cooking can continue.
What does Frymaster error return valve not closed mean?
A return valve must close after filtering so that oil does not drift between the pan and the vat while cooking or draining. The M3000 computer commands the valve to close and expects confirmation. When the valve fails to close, or the computer cannot confirm that it closed, it logs E13 and shows ERROR RETURN VALVE NOT CLOSED. A valve that stays partly open can let oil flow in a direction it should not, for example returning oil to the pan during a drain, or pulling oil from the vat. The manual gives the meaning and one action, call service. The valve may be mechanically stuck, the actuator may stop short, or the closed-position signal may not be reaching the computer. The computer will not trust the position until it is repaired. E13 is part of the Gen II LOV M3000 table and is not on the 3000/3010 controller.
Affected models and control systems
Gen II LOV fryers with the M3000 computer, BIELA14 series electric; the BIGLA30 gas fryer uses the same computer family.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- ERROR RETURN VALVE NOT CLOSED on the computer
- Oil level changing without a filter run
- Oil in the filter pan after cooking
- Alarm sounding
Possible causes
Likely causes — what usually sits behind error return valve not closed on this control. A technician confirms which one it is before any part is replaced.
- Shortening residue holding the valve off its seat
- A return actuator that does not complete its closing stroke
- A closed-position switch that is out of adjustment
Safe checks before calling for service
- Look at the vat oil level and whether oil has collected in the pan.
- Keep hands away from the valve area while it is hot.
- Do not start a filter cycle until the valve is checked.
- Note the vat and the time, then call service.
How a technician diagnoses error return valve not closed
- Read the error log for E13 and related E10, E11 or E12 codes.
- Inspect the return valve and seat for buildup once the oil is cool.
- Check actuator closing travel and linkage movement.
- Test the closed-position sensing.
- Replace the stuck or failed part after the test, then run a filter cycle to confirm.
- The valve is in a hot oil line, and a partly open return can move oil unexpectedly.
- Actuator and sensor tests are done with the computer commanding valves on a live fryer.
- Several parts can give this same message, so replacing them blind costs more.
How error return valve not closed differs from similar codes
E13 is the return valve not closing; E12 is the same valve not opening. Neither code exists on the 3000/3010 controller.
Technical reference
- Maker documentation
- Frymaster owner support
- Edition
- May 2011, 819-6446
- Models / control
- 3000 controller / M3000
- Section
- 1.14.4 Error Log Codes, p. 1-35
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Frymaster fryer error codes
Why does the pan have oil after cooking?
A return valve that did not close can let oil move back toward the pan. Check with a technician.
Is E13 worse than E12?
They affect different parts of the filter cycle. E13 can move oil in the wrong direction, while E12 stops oil returning.
Will the message go away when I power cycle?
It may reset, but if the valve is still stuck the computer will report it again.
Need help with Frymaster error return valve not closed?
A technician confirms the cause on site and gives you the price in writing before any work starts.