Vulcan Commercial Fryer Error Code OPEN PROBE: Temperature Probe Open
OPEN PROBE on a Vulcan PowerFry with the Solid State (D) control means the control sees a break in the temperature probe circuit. It disables the heat demand, cancels cooking cycles and locks the operator buttons. Switch the fryer off, let the oil cool, try one restart and call us if the message returns.
High: the fryer stops heating and the controls lock until the circuit is repaired.
What does Vulcan OPEN PROBE mean?
The oil temperature probe is an RTD sensor sitting in the vat, and the control measures its resistance many times a second. A healthy probe returns a value that matches a temperature. If the circuit is broken, the control sees an open circuit instead, and it cannot know how hot the oil is. Rather than guess, it shows OPEN PROBE, disables the heat demand, cancels any cooking cycle and locks the operator buttons. The fryer stops heating, and the keys do not respond until the open circuit is dealt with. A plug that has pulled loose or corroded, a wire broken inside the lead, a probe that has failed internally or a lead burned near the burner each leave the same message. One restart can show whether the contact was momentary. A repeat means the circuit needs testing by someone with a meter.
Affected models and control systems
This applies to Vulcan VK/TR PowerFry gas fryers with the Solid State (D) control, including the 1TR45, 1VK65 and 2TR85. The Computer (C) control reports the same condition as PROBE OPEN.
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
- OPEN PROBE on the display
- Heat off and keys unresponsive
- Vat cooling down mid-service
- Temperature reading missing or dashes
Possible causes
Listed in Vulcan's documentation
- A probe plug that has pulled loose or corroded in the connector
- A broken wire inside the RTD probe lead
- A failed RTD sensor that no longer completes the circuit
- A lead burned by heat close to the burner area
Other likely causes — what usually sits behind OPEN PROBE on this control. A technician confirms which one it is before any part is replaced.
- Probe lead stretched when the vat or basket lift was moved during cleaning
- Connector contacts green with corrosion from steam and grease
- Lead insulation cracked where it bends against the vat wall
Safe checks before calling for service
- Switch the fryer off and let the oil cool completely.
- Do not reach into the vat or move hot oil.
- Switch the fryer back on and see whether the message clears.
- If OPEN PROBE returns, call us.
- If gas is ever in the room, step out and call the gas utility first.
How a technician diagnoses OPEN PROBE
- Read the message and let the oil cool.
- Inspect the probe lead along its full path for burns or breaks.
- Check the connector for corrosion and seating.
- Measure probe resistance at a known temperature and compare it with a reference.
- Test continuity from the connector to the control input.
- Replace the probe or lead, then verify a normal heat-up.
- The probe sits in hot oil, and the lead runs close to the burner on a gas appliance.
- Resistance and continuity checks are made with a meter against reference values.
- Control inputs sit in a cabinet with line-voltage wiring.
How OPEN PROBE differs from similar codes
OPEN PROBE is the Solid State (D) wording. The Computer (C) control calls the same condition PROBE OPEN.
Technical reference
- Document
- VK/TR/VFRY Gas Fryers Installation & Operational Manual F-32971 Rev U (12-17), Alarms and Error Messages p.29-30
- Maker documentation
- Vulcan owner support
- Edition
- F-32971 Rev. U (12-17)
- Models / control
- Vulcan VK/TR PowerFry Solid State (D) control
- Section
- Alarms and Error Messages, printed pp. 29-30 (plus Troubleshooting Chart p. 30)
- 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 Vulcan fryer error codes
Why did the keys stop working?
The control locks the operator buttons while the probe circuit is open.
Is the oil dangerous?
It may still be hot. Leave it in the vat until it has cooled completely.
Will a new probe always fix it?
Often, but a loose plug or a damaged lead can look the same, so the circuit is tested first.
Need help with Vulcan OPEN PROBE?
A technician confirms the cause on site and gives you the price in writing before any work starts.