Blakeslee Conveyor Dishwasher Error Code C5: Pre-Rinse Overtemperature
C5 PRE-RINSE OVERTEMPERATURE means the pre-rinse section is over temperature. The manual says to turn off the appliance and contact Technical Service. Let it cool and have a service technician inspect the heater control.
High: an over-temperature section is a safety condition and the machine must stay off.
- Code
- C5
- Maker
- Blakeslee
- Equipment
- Conveyor dish machines
- Applies to
- Blakeslee rack conveyor with pre-rinse section (PDF is Blakeslee's 'RC64 User Manual'; the RC86 user manual is the same document); prints no model name
What does Blakeslee error code C5 mean?
A heated tank must never run past its upper limit, so the control compares the pre-rinse temperature with a ceiling. If the reading goes above it, the heater is cut and the display shows C5 PRE-RINSE OVERTEMPERATURE. The manual lists it as the pre-rinse section over-temperature, with the instruction to turn off the appliance and contact Technical Service. No reset step is given, because the heat itself is the problem. The cause can be a relay that has stuck closed, a probe that reads low so the control keeps heating, or a tank that has run low on water with the element still powered. It is the high-limit counterpart of C3. The control stops the machine, since more heating on an over-limit tank risks scalding and damage.
Affected models and control systems
Blakeslee rack conveyor dishwasher with a pre-rinse section. The PDF is Blakeslee's RC64 User Manual, and the RC86 manual is the same document; it prints no model name.
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
- C5 PRE-RINSE OVERTEMPERATURE on the display
- Steam rising from the first station
- Water very hot to the touch
- Machine stops and stays off
Possible causes
Likely causes — what usually sits behind error code C5 on this control. A technician confirms which one it is before any part is replaced.
- Heater relay stuck closed
- Pre-rinse probe reading lower than the real temperature
- Tank running low on water with the heater on
- Control output keeping the pre-rinse heater powered after the limit
Safe checks before calling for service
- Turn the appliance off, as the manual instructs, and switch off the disconnect.
- Keep clear of the first station and let everything cool.
- Do not restart to see whether it clears.
- Check that the floor is dry and nothing is leaking.
- Note the display and any steam, hissing or odor.
How a technician diagnoses error code C5
- Read the alarm history and note any earlier fill or probe alarms.
- With power locked out, check the heater relay for welded contacts.
- Compare the probe reading with a reference thermometer.
- Confirm the tank fills and keeps its level.
- Test the element and safety devices and replace the confirmed part.
- An over-temperature tank holds scalding water.
- A stuck relay is a line-voltage problem found with the supply locked out.
- Telling a bad probe from a bad output needs a meter and a reference thermometer.
How error code C5 differs from similar codes
C5 is the pre-rinse running too hot. B5 and E5 are the same alarm for boiler 1 and wash tank 1.
Technical reference
- Document
- Instructions for Use and Maintenance (USA) rack conveyor with pre-rinse section; published on blakesleeinc.com as 'RC64 User Manual'
- Maker documentation
- Blakeslee owner support
- Edition
- COD. 4900E_U_USA, Ed. 01 - 02/2018
- Models / control
- Blakeslee rack conveyor with pre-rinse section (PDF is Blakeslee's 'RC64 User Manual'; the RC86 user manual is the same document); prints no model name
- Section
- Chapter 12.2.1 Alarms description (pp. 54-55)
- 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 Blakeslee conveyor dish machine error codes
Is C5 a safety alarm?
Yes. The manual says to turn the appliance off.
Can I reset and carry on?
No. If the heater cannot switch off, it will overheat again.
Could low water cause C5?
It can, since the element heats a smaller volume faster.
Need help with Blakeslee error code C5?
A technician confirms the cause on site and gives you the price in writing before any work starts.