What to check yourself
Step 1. Check the model number first
GE gives two different answers for 999 and they depend on the model. On GDT225, PDT145 and ZDT165 the code is a control lockout: hold Cycle Select and Start together for five seconds until 999 disappears, then press any button. If that clears it and it stays clear, you are done. On any model with Floor Protect with Alert, go on to the next step.
Step 2. Cut the power and the water
Breaker off before anything else. Water in the base pan sits beside the pump motor and the harness, and that is not a place to work live. Close the supply valve under the sink too.
Breaker off, not just the panel. The pan is under the electrics.
Step 3. Remove the kickplate and dry the pan
Two screws hold the panel at the bottom front. Behind it is the pan with the moisture sensor. Towel out the water and leave the door open and the panel off. The sensor has to dry, and it takes a day, sometimes two; while it is wet the code will return whatever you press.
Step 4. Work out where the water came from
In order of how often it turns out to be the cause: foam from the wrong detergent or a pod plus rinse aid in soft water, which climbs the tub and reaches the pan; the door gasket at the bottom corners; the pump shaft seal weeping under the tub; a hose clamp or the inlet valve dripping; a machine not level, so pan water runs to the sensor end. Run a rinse cycle with the panel off and watch.
What a technician will look at
Described so you know what you are paying for, not as steps to repeat.
Find and fix the leak
If the pan refills within a cycle, the leak is inside: pump seal, sump seal or a split hose. The technician runs the machine with the panel off and follows the drip. A sensor or microswitch that trips with a dry pan is the false alarm case, and it is diagnosed the same way.
When to call a technician
As soon as the pan refills after you dried it. A door gasket is an owner's job; a pump seal or an internal hose is not, and running a machine that keeps wetting its own electrics is how a cheap repair becomes a new dishwasher.
What the repair costs
| Repair | Part only | Fitted by a technician |
|---|---|---|
| Control reset on GDT225, PDT145 and ZDT165 | - | Free |
| Drying the pan, changing the detergent | - | Free |
| Diagnosis alone | - | $70 to $130 |
| Door gasket replacement | $18 to $80 | $50 to $150 |
| Leak sensor or flood switch replacement | $9 to $42 | $100 to $200 |
| Pump seal or pump replacement | $50 to $120 | $150 to $400 |
A new machine of the same class runs $500 to $1,500. Once a quote passes about a third of that on an older appliance, the repair stops making sense.
Codes people confuse this with
Questions people ask
- I unplugged it for ten minutes and 999 came straight back. Why?
- Because the sensor is still wet. A power cycle clears the control, not the pan. Dry the pan and give the sensor a day; then the code clears on its own.
- There is no puddle on the floor. How can it be a leak?
- The pan is designed to catch it. Floor Protect holds a good deal of water before anything reaches the kitchen floor, which is the point of it. The leak is real; it just has not got out yet.
- Is 999 the same as LEAK DETECTED?
- On the leak alert models, yes: some displays show the number, some the words, and some both. The number on the entry models without the alert is the separate reset case above.
Which machines this applies to
Applies to
Current GE, GE Profile, Café and Monogram dishwashers. On GDT, PDT, CDT and ZDT models with Floor Protect with Alert it is the leak case. On GDT225, PDT145 and ZDT165 it is the control reset case, and GE lists those models by name.
Last checked
2026-08-28