Jackson Dishwasher Error Code F6: No Water in Wash Tank
F6 on a Jackson DishStar HT-E means the control could not confirm water in the wash tank, so the wash heater is not allowed to run. Check the supply valve and pressure first. If F6 returns, the fill circuit, the wash probe or the float switch needs a technician.
High: the heater is locked out and the machine will not wash until the cause is fixed.
- Code
- F6
- Maker
- Jackson
- Equipment
- Dish machines
- Applies to
- DishStar HT-E undercounter dishmachines (same F-code table is also printed in the DynaTemp door-type manual 07610-004-29-29-D, pp. 22-24, where F12 is 'Not Used
What does Jackson error code F6 mean?
The wash heater sits in the tank that holds the cleaning solution, and it must never run without water around it. The control therefore looks for confirmation that the tank holds water before it lets the heater work. When it cannot get that confirmation, it shows "F6 Service needed" with the line "No water in wash tank". The manual lists six causes: low or no water pressure, an inlet valve or fill relay that has failed, a wash heater contactor that is not turning off, a failed wash temperature input (T1) on the IO module, a failed probe T1, and a failed float switch that lets heaters run with no water in the tub. Read together, the list covers three things: water not arriving, water arriving but the control not seeing it, and the heater being powered anyway. The first has an operator check, the supply pressure of 10 +/- 2 PSI. The other two require the cabinet to be opened.
Affected models and control systems
Jackson DishStar HT-E undercounter dishmachines. The F-code table is also printed in the DynaTemp door-type manual, pp. 22-24.
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
- Display reads F6 Service needed, No water in wash tank
- Machine will not start or stops partway through filling
- Tank is empty or only partly filled
Possible causes
Listed in Jackson's documentation
- Low or no water pressure
- Inlet valve or fill relay failed
- Wash heater contactor not turning off
- Wash temperature input (T1) on the IO module failed
- Probe T1 failed
- Float switch failed, letting heaters run with no water in the tub
Other likely causes — what usually sits behind error code F6 on this control. A technician confirms which one it is before any part is replaced.
- A supply valve that was shut after a delivery, a repair or a long closed day
- Mineral build-up in the fill solenoid screen that slows the water down
- A float that sticks on residue from heavy food soil
Safe checks before calling for service
- Check that the machine's water supply valve is open all the way.
- Look at the tank through the door if it is safe to do so: is there any water at all?
- Turn the machine off, wait a minute, and turn it on again.
- Note what the screen showed just before F6 and whether the tank was visibly empty.
How a technician diagnoses error code F6
- Confirm F6 and measure the incoming water pressure against 10 +/- 2 PSI.
- Verify that the fill relay supplies voltage to the fill solenoid and replace the failed part.
- Check the wash heater contactor for welded contacts.
- Substitute a 1.2 kOhm resistor for T1 and verify the wash heater turns off; otherwise replace the IO module.
- Verify T1 resistance against the manual's table and replace the float switch if the others pass.
- The wash heater and contactor run on the machine's full line voltage.
- A float switch that looks clean can still be stuck, and finding it means draining the tank.
- Running a heater in an empty tank would destroy it, so a technician confirms the water before heat is restored.
How error code F6 differs from similar codes
F6 is the wash tank version of F1. F3 and F8 also describe a tank that is not filling, but they include the door.
Technical reference
- Document
- DishStar HT-E Installation, Operation, and Service Manual
- Edition
- 07610-004-43-79-J (Rev J)
- Models / control
- DishStar HT-E undercounter dishmachines (same F-code table is also printed in the DynaTemp door-type manual 07610-004-29-29-D, pp. 22-24, where F12 is 'Not Used
- Section
- Fault Codes / Troubleshooting, printed pp. 26-28 (PDF pp. 33-35)
- 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 Jackson dish machine error codes
What is the difference between F6 and F3?
F6 says the control cannot confirm water in the wash tank, and it stops the heater. F3 is about the fill itself and the door.
Will F6 go away if I refill by hand?
We do not recommend that. The control needs to prove the tank is filling through its own circuit.
Can I use the machine with F6 showing?
No. The wash heater is not allowed to run, so the machine will not wash properly.
Need help with Jackson error code F6?
A technician confirms the cause on site and gives you the price in writing before any work starts.