I have a fisher and Paykel dishwasher model 920, It gets stuck at 33 minutes left and then eventually gets the F4 fault code. I have replaced the temp sensor and made no difference.

Bart, November 2012

That part underneath is not the temperature sensor it is an overheat cut out in series with the element. If the temperature of the cabinet gets up to 85 deg C it will go open circuit and shut off the heater until it cools down then resets back to normal. If you got continuity across the two terminals at normal temperature then it is ok. The temperature sensor is inside the door panel attached to the inner door panel. The control module is waiting for the temperature to reach a set temperature. If this has not been reached after 50 minutes it gives up and signals a fault F4. I will say again check the element for continuity - you should get approx. 35 ohms terminal to terminal. If element ok then check the control module for damage. I would say that is where the problem lies. That is the usual cause of this error. You will have to take it out of the door panel, open the case and look for bad solder joint or faulty relay. Refer to the wiring diagram inside lower panel for location of the wire for the element to aid you in which area to look on the PCB

Lincoln Appliance NZ, November 2012

Hi Lincoln appliance
there is a temp sensor under the unit, i tested it by putting top section in some boiling water and check for ohms change, found no change so replaced it, tried ohms check on element and it tested ok(followed instructions on net how to check with multimeter).
Why would it get stuck at 33 mins for ages then eventually shows F4 fault?, can i do diagnostic on this, ive see other units have diagnostic ability. what are you suggestions to try next?

Bart, November 2012

Hi Lincoln appliance
there is a temp sensor under the unit, i tested it by putting top section in some boiling water and check for ohms change, found no change so replaced it, tried ohms check on element and it tested ok(followed instructions on net how to check with multimeter).
Why would it get stuck at 33 mins for ages then eventually shows F4 fault?, can i do diagnostic on this, ive see other units have diagnostic ability. what are you suggestions to try next?

Bart, November 2012

How did you replace the temperature sensor when it is not sold as a spare part and is wired in to the main control board? Also, why did you replace the temperature sensor? Did you test it first and find a fault with it or just felt like replacing parts at random hoping to do the right thing? F4 means the water is not heating. It will be either a faulty heater element, a wire loose or broken between the control board and the element or a problem on the control board itself. That is the most common reason.

Lincoln Appliance NZ, November 2012