Samsung DMT300RFW dishwasher is stopping mid cycle without draining, continuously flashes Heavy / Delicate. Power off/on, and press buttons to drain. Cleaned out water flow assembly - same issue.

A Samsung Dishwasher flashing the Delicate and Heavy light indicates a Heater Error has been detected by the internal electronic diagnostics. You can find more info here
https://appliancerepairinfo.com/samsung-dishwasher-delicate-and-heavy-light-flashing/

How old is your dishwasher? How long has it been since it has been serviced?

The lights that are blinking are indicating an error code--the particular code you describe is a "heater error". You will have to check the circuit for an open heater element, loose or broken wire, defective main control board. The part number for the main board is DE92-02256C. Hope I helped you!

Maybe your heater does not work
thr thermostat will allow the next cycle after water heats

Usually caused by a draining problem. Check your drain hose where it goes into you garbage disposal. That drain hose should be mounted up so water from the sink and garbage disposal can't backwash into the dishwasher. Use a clamp or zip tie to mount the drain hose so it goes up at least 4 to 6 inches above the garbage disposal port.

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Had a look in the user manual for your dishwasher.http://downloadcenter.samsung.com/content/UM/201211/20121101114232459/DW7933LRASR-00141A-02.pdf

Page 26 shows blinking Heavy light means there is leakage in the dishwasher. Most likely there is water in the base under the drain sump which could cause the flood switch to trip. Turn mains power to dishwasher off. Pull it out from under kitchen bench without breaking the hoses. Put some towels on the floor and turn dishwasher back and forth on incline to get water out. Wait a little and turn on. If no difference then you need to dry the base and find the source of the leak. More likely the door seal.

If three lights are blinking (normal, heavy, quick)... I just had this same problem, and I think I figured it out. There was water on the bottom from the last cycle, so I pressed HEAVY and DELICATE at the same time for 3 seconds (you'll see it printed on the control panel), and the unit drained. I was then able to start the new cycle normally without the error. Hope that helps!

A Samsung Dishwasher flashing the Heavy Normal and Quick light indicates a Low Water Level Error has been detected by the internal electronic diagnostics.
You can find more info here
https://appliancerepairinfo.com/samsung-dishwasher-heavy-normal-and-quick-light-flashing/

START/RESET status indicator light flashing

You have pressed the indicator light flashing START/RESET pad while the START/RESET dishwasher is running. This will cancel the cycle. The light will stop flashing after the dishwasher drains (about 90 seconds).

• Press the pad once to start the dishwasher. Press the pad a second time when the dishwasher is running only if you wish to cancel the cycle.

Power to the dishwasher was turned off while a cycle was running and power has just been restored to the dishwasher. The blinking lights indicate that the dishwasher is draining the potential water inside.

• The light will stop flashing after the dishwasher drains. A new cycle will start automatically.

Good luck

Press the cancel button, Then cut power to the dishwasher for a period of time. restore power to it then try a cycle.