Dishwashers troubleshooting: water in, water out, nothing else.
A dishwasher needs water in, water out and a spray arm that turns. Nine complaints in ten are one of those three, and the look takes a flashlight and the bottom rack out. Check the install first on a new unit — the drain hose loop is the most common miss.
First use: what is normal
A new machine can do things on its first run that look like a fault and are not. Here is what the makers say is normal, what to do first, and where the line is.
Normal the first time
- A little water in the tub, or dripping from the drain hose, when it is brand new. It is left from factory testing.
- A new-plastic smell that lasts until after several cycles.
- Moisture on the walls and door after a cycle. That is part of how it dries.
Do this first
- 1Run several cycles with detergent to clear the new smell.
Where the line is. A burning smell, a smell that does not fade after several cycles, or water on the floor is not normal: stop using it and text us.
Before you touch anything
The install rules that decide most of what follows. Check these once; they rule out the causes that look like a broken machine and are not.
The drain hose must loop up to the underside of the counter (a high loop) or through an air gap before it joins the sink drain, or the sink backs up into the tub.
On a new install under a garbage disposal, the knockout plug inside the disposal's dishwasher inlet has to be punched out — a new dishwasher that will not drain almost always has the plug still in.
Hot water at the sink before you start a cycle: the first fill takes whatever is in the pipe.
Water left in the bottom after a cycle
In this order
- New install: is the disposal's knockout plug punched out?
- Is the drain hose kinked behind the unit or lying flat with no high loop?
- Is the filter at the bottom of the tub clogged (lift it out and rinse)?
- Does the drain pump hum at the end of the cycle?
What is usually behind it
A blocked path out — the knockout plug, a kink, a clogged filter or a jammed drain pump (a piece of glass or a bone).
What to do
Punch the plug, straighten and high-loop the hose, clean the filter. A pump that hums but will not move water usually has something in the impeller — reachable from the sump with the lower spray arm off.
Will not fill or starts and stops
In this order
- Is the water supply valve under the sink open?
- Is the door latched all the way (the latch has to click)?
- Is the float (the small dome at the tub floor) stuck up?
- Any code on the panel?
What is usually behind it
A closed valve, a door the latch does not read as shut, a stuck float, or a failed inlet valve.
What to do
Open the valve, free the float and clean under it, make sure the door latches. An inlet valve that hums but passes no water is a part behind the kick plate.
Dishes come out dirty or gritty
In this order
- Do the spray arms spin freely by hand, and are their holes clear?
- Is the filter clean?
- Is the water hot (120°F) at the start?
- Are the dishes blocking the arm or the detergent door?
What is usually behind it
Spray arms clogged or blocked, a dirty filter recirculating grit, cold water, or a detergent cup that cannot open.
What to do
Clear the arm holes with a toothpick, clean the filter monthly, run the sink hot first, and load so nothing blocks the arms or the cup. Use rinse aid — it does more for drying and spotting than detergent does.
Dishes come out wet
In this order
- Is the rinse aid dispenser full?
- Is heated dry or a dry boost option selected?
- Plastics on the bottom rack? Plastic will not dry in any dishwasher.
What is usually behind it
No rinse aid, a dry option off, or plastic dishes — modern dishwashers dry by condensation and need rinse aid to sheet the water off.
What to do
Fill the rinse aid, turn on the heated or extended dry, and crack the door open at the end of the cycle for a few minutes.
Water on the floor at the front
In this order
- Is the door gasket seated all the way around and not torn?
- Is the unit level and the front feet set so the door closes square?
- Is a tall item spraying water at the door?
- Too much detergent or dish soap used? Suds leak.
What is usually behind it
A gasket off its seat, an unlevel install, a spray arm aimed at the door by a dish, or suds from the wrong soap.
What to do
Seat or replace the gasket, level the unit so the door edges meet the tub evenly, and never use dish soap. If a suds spill happened, run a rinse cycle with a cup of white vinegar.
A code on the panel or the lights blinking
In this order
- Write the code down and check the manual — most makers put drain, fill, heater and door codes in a short table.
- Shut the breaker for five minutes and restart.
- Does the code return at the same point in the cycle?
What is usually behind it
A sensor reading a real problem (no drain, no fill, no heat) or a board that needs a reset.
What to do
Fix what the code names first (see the drain and fill entries). A heater code with cold water after the main wash is the heating element or its relay — a service part.
Grinding, buzzing or a loud hum
In this order
- Pull the lower rack and spray arm — anything hard in the sump (glass, a pit, a bone)?
- Does the buzz come only during draining?
- Is the unit screwed to the counter so it does not rock?
What is usually behind it
Debris in the pump, a drain pump impeller hitting something, or an unanchored unit.
What to do
Clear the sump, anchor the unit to the counter or cabinet sides. A grinding wash pump with a clean sump is a motor call.
When it's a warranty call
Every unit leaves with the manufacturer's full factory warranty. These are the faults that warranty exists for — once the checks above have ruled out the install, the power and the vent, call the maker's line with the model and serial, and text us if you want a hand with the claim.
A circulation or drain pump that grinds or stalls with a clean sump.
A control board that throws the same code cold.
A heater that never warms the water after the drain and fill are proven.
All units are surplus inventory (open box, cancelled order, customer return, overstock, or minor scratch & dent). Every unit includes the manufacturer's full factory warranty. Please inspect thoroughly in person before purchasing — cosmetic imperfections or missing accessories are possible.
Text us the model number and what it's doing — we'll point you at the next step.
A fix, a part, or a warranty call — the plate's model and serial plus one line about the symptom is all it takes to tell which.
These pages are educational. Every appliance is a little different — follow the manufacturer's manual and local code, and leave gas, water heater and 240V work to a licensed installer.