Samsung DMT300RFS/XAA dishwasher Parts

On the Samsung DMT300RFS dishwasher, we use Delay Start to have the wash cycle begin later; you select your cycle first, set the delay time, then press Start and keep the door fully closed so the dishwasher can start automatically when the delay ends. For the exact button sequence and delay-hour options, use the DMT300RFS owner's manual.

How to set Delay Start (typical Samsung control steps)

• Load dishes and add detergent and rinse aid.
• Close the door firmly.
• Select the wash cycle you want (the cycle light should illuminate).
• Press Delay Start to choose the number of hours to delay (each press usually advances the delay).
• Press Start/Pause; the dishwasher begins after a few seconds, then waits and starts when the delay countdown finishes.

What to check if Delay Start will not run

• Door not fully latched: if the door is slightly ajar, the selected cycle will not start.
• Cycle canceled: pressing the selected cycle button again can turn the light off and cancel the cycle.
• Power interruption: a breaker trip or power loss can reset the control and clear the delay.
• Control lock or mode setting: confirm the control panel is accepting button presses.
• Standing water or drain issue: resolve draining problems first so the next start is normal.

Quick reference

What you do	What you should see	What it means
Select a cycle	Cycle light on	Cycle is chosen
Set Delay Start	Delay indicator or time changes	Start is scheduled
Press Start/Pause	Start engages, then waits	Dishwasher will start later

Why it matters

Delay Start helps you run the dishwasher during off-peak hours or when hot water demand is lower. It also prevents starting a cycle with the door not fully closed, which stops the cycle for safety.

Last updated: February 2026

To reset (turn off) Child Lock on your Samsung dishwasher model DMT300RFS, press and hold the Child Lock button for about 3 seconds until the Child Lock indicator light turns off. When Child Lock is on, only the Power button works when no cycle is running.

What you should see when it works

• The Child Lock indicator light turns off.
• The control panel stops blinking/ignoring button presses.
• You can select a cycle and options normally.

If the buttons still blink or won’t respond

Try these quick checks in order:

• Make sure the dishwasher is not actively running a cycle; Child Lock behavior can differ mid-cycle.
• Press and hold the correct key labeled Child Lock for a full 3 seconds (a quick tap will not change it).
• Close the door fully; a door not fully latched can prevent normal operation.
• Turn the dishwasher off, wait 10 seconds, then turn it back on and try the 3-second hold again.
• If an error code is showing, look it up first because some faults can limit control-panel operation.

Child Lock behavior at a glance

Status	Child Lock light	What works	What won’t work
Child Lock ON	On	Power (when no cycle is running)	Most cycle/option buttons
Child Lock OFF	Off	All normal selections	None (normal operation)

Why it matters

Child Lock is designed to prevent kids (or accidental bumps) from starting or changing a wash cycle. If it’s enabled, the dishwasher can look “stuck” because the control panel won’t accept most selections.

For the exact button location and indicator-light details for your control panel, use the DMT300RFS owner’s manual. For code-related lockouts, use Samsung dmt dishwasher error codes.

Last updated: February 2026

To force a drain on your Samsung DMT300RFS dishwasher, use the Cancel and Drain function: press Cancel/Drain (or press and hold Start for about 3 to 5 seconds, depending on the control panel), then close the door so the unit can run the drain pump and empty the tub. For exact button names, follow the DMT300RFS owner's manual.

Quick steps to start a drain cycle

• Open the door and press Power.
• Press Cancel/Drain (or press and hold Start for 3 to 5 seconds).
• Close the door firmly so the dishwasher can run.
• Listen for the drain pump; draining usually starts within a few seconds.
• When the cycle ends, open the door and check the sump area for standing water.

If it still will not drain

A drain problem is usually a kinked/clogged drain hose, a blockage in the sump area, or a drain pump issue.

• Check the drain hose under the sink for kinks, crushing, or a high loop that collapsed.
• Clear the air gap (if your setup has one) and the garbage disposal inlet (if connected).
• Remove and clean the filter area and sump inlet; food debris can restrict flow.
• If an information code indicates a drain error, follow the troubleshooting steps in Samsung dmt dishwasher error codes.
• If the dishwasher hums but does not move water, the drain pump may be failing; replacing the dishwasher drain pump DD31-00005A is a common fix.

What to check first (fast diagnosis)

What you notice	Most likely cause	What we recommend
Water stays, no sound	Control not entering drain	Retry Cancel/Drain; confirm door fully latched
Hums but little or no water leaves	Partial blockage or weak pump	Check hose/air gap; inspect sump; consider drain pump
Drains slowly	Hose restriction or clog	Straighten hose; clear air gap/disposal inlet
Drain error code shows	Drain path problem	Use the error code steps and inspect hose/pump

Why it matters

Standing water can lead to odors, poor cleaning, and repeated drain errors. Getting the Cancel/Drain function working and keeping the drain path clear helps protect the pump and prevents leaks (your dishwasher uses sensors to detect abnormal water conditions).

Last updated: February 2026

The most common problem we see with Samsung dishwashers like model DMT300RFS is a drain-related issue: the dishwasher will not drain fully, stops mid-cycle, or shows a drain or leak condition. The fastest wins are checking the drain path, confirming the door closes, and using the troubleshooting steps in the DMT300RFS owner's manual.

Most common symptoms and what they usually mean

• Water left in the bottom: drain hose kinked, drain path restricted, or drain pump issue
• Stops and beeps with an information code: the dishwasher detected a drain, fill, heat, or leak condition
• Poor cleaning: spray arm holes blocked, loading issue, or wash system restriction
• Leaking: door sealing surface dirty, door baffle/gasket issue, or overfill/leak detection
• Will not start: door not latched, control lock, power supply problem

Quick checks we recommend first (10 to 20 minutes)

1. Cancel the cycle and run Cancel/Drain (per the manual’s troubleshooting flow).
2. Inspect the drain hose under the sink for kinks, crushing, or a high-loop/air-gap issue.
3. Check that the door closes firmly and nothing is blocking the latch.
4. Clean out visible debris in the tub bottom area and confirm the spray arms spin freely.
5. If an information code is showing, match it to the guide and follow the listed action steps.

Common problems and the parts that often fix them

Problem you notice	What to check first	Part that’s commonly involved (if needed)
Not draining	Hose routing, clogs, drain path	Drain pump, drain hose, check valve area
Leak or leak code	Door sealing surfaces, tub edge, float area	Dishwasher door baffle DD69-00017A, door vent gasket
Poor cleaning	Spray arm holes, loading, water feed	Spray arms, water feed tube, chopper area
Fill or water level errors	Supply valve open, inlet screen, water level sensing	Water inlet valve, dishwasher water-level sensor DD61-00236A

Why it matters

Drain and leak conditions can stop the cycle to protect your kitchen and the dishwasher. Addressing hose routing, clogs, and door sealing early prevents repeat shutdowns, standing water odors, and poor wash results.

For code-specific help, we use the Samsung dmt dishwasher error codes guide alongside the manual.

Last updated: February 2026

For the Samsung DMT300RFS dishwasher, the best everyday choice is a normal wash with rinse aid enabled; it balances cleaning and energy use. Use higher-heat options (like Sanitize) when you need extra hygiene or are fighting heavy soil; confirm option names in the DMT300RFS owner's manual.

Best settings by goal

• Everyday mixed loads: Normal cycle, rinse aid on
• Heavily soiled pots and pans: Heavy cycle (or the strongest wash cycle available)
• Extra hygiene: Sanitize option (raises final rinse temperature for sanitization)
• Better drying and fewer spots: Use rinse aid; choose heated dry if your model offers it
• Hard water: Rinse aid plus an extra rinse option (if available)

Quick comparison

What you want	Setting to use	What to expect
Best overall balance	Normal	Good cleaning with reasonable run time and energy use
Maximum cleaning	Heavy	Longer cycle; better on baked-on soil
Sanitized final rinse	Sanitize	Higher final rinse temperature; longer cycle
Drier dishes	Heated dry + rinse aid	Drier plastics and fewer water spots

Loading and setup tips that matter as much as the setting

Even the best cycle will underperform if spray is blocked. For DMT300RFS, we recommend these basics:

• Scrape off large food pieces before loading
• Load so open sides face the spray (don’t “nest” bowls)
• Keep tall items from blocking the middle and upper spray paths
• After loading, spin the spray nozzles by hand to confirm nothing hits
• Use only automatic dishwasher detergent (not hand dish soap)

Why it matters

Choosing the right cycle and options helps the circulation system and spray arms clean efficiently, reduces redepositing soil, and improves drying. Using Sanitize only when needed also helps keep cycle time and energy use under control.

Last updated: February 2026