Samsung dmt400rhs blinking HEAVY light - Samsung DMT400RHS Builtin Dishwasher

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/

usersmanualguide.com

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!

It depends on which 2 lights are blinking. Samsung uses a combination of blinking lights to tell what's wrong; sometimes it's 1 light; sometimes it's 2; sometimes it's 3 (or more), but we need to know what lights are blinking to tell what's wrong.

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

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

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.

Try to unstick the float. The float tells the DW how much water is in it at any given time. It is shaped like a mushroom on the bottom of the DW basin. Gently pick it up and set it back down. Does it seem free? Try the cycle again.

I have a Samsung DMT400RHS and I started getting the low water level error ('Normal'+Heavy'+Smart Auto' LED blinking). The error started intermittently a few weeks ago, but the the last day or two the problem was solid, and simply restarting the cycle no longer worked.
I looked of the code in the dishwasher user guide and it said 'low water level.' Searched the internet and located the repair manual at tradebit.com for $15. The manual was well worth the $15.
The manual suggested: 1) loose level sensor connector 2) Faulty Assy case sensor or stuck floater aka 'remove foreign matter' 3) Bad Main PBA assy.
Since we do 10+ loads a week for the last 18 months the stuck floater seemed to be the most likely cause.
Go to Samsung DMT400RHS Low Water Level Error ('Normal'+Heavy'+Smart Auto' LED) (new link is https://photos.google.com/album/AF1QipNtp1neOR7icVG8cSs71bLpxQD5k_xljiWcJD2P click the i on each picture to see the caption - DM 04/17/2016) to see the pictures and read the captions documenting what I did. Do this at your own risk. You must turn off and disconnect the electric power and turn off the water supply before you begin.

It sits at the bottom of the lowest plastic tub. assuming you have no more active leak, you may have to tilt is on it's side to drain the last bit of water.

read you instruction manual, section troubleshooting, go to the menu, and proceed. If you do not have instr.manual download from www. retrevo.com or www.fitness.manualsonline.com
However you can reset from the main power, reset the c.breaker that control the dishwasher machine.
God bless you