What to check yourself
Step 1. If the machine is new, check the disposal knockout plug
Read this first if the machine was installed in the last few weeks. A new garbage disposal ships with a plastic disc sealing the dishwasher inlet, and it has to be punched out. Miss it and the very first cycle ends in FTD. Technicians on the trade forums say it is the single most common cause on a fresh install.
Step 2. Take the filters out and clear the sump
Lower rack out, twist the fine filter and lift the coarse one, rinse both, then look into the sump with a torch. Fruit stickers, rice and glass gather on the drain side. While you are there, lift the small flood float in the sump and let it drop: a float held up by debris tells the control the tub is full.
Check for glass before reaching in.
Step 3. Follow the drain hose and find the high loop
Pull the machine forward and trace the hose. A kink behind the machine or a hose crushed in the cabinet is enough. The hose should rise to the underside of the counter before dropping to the drain; a loop that has sagged lets sink water run back and gives FTD at the end of a cycle that seemed fine.
Step 4. Clear the air gap and run the disposal
Cap off the chrome cylinder by the tap and clear the sludge inside. Run the disposal with the tap on for half a minute. Both narrow the outlet slowly, and on a machine that has drained for years this is where the restriction usually is.
Step 5. Look at the detergent
Too much detergent, a pod plus rinse aid in soft water, or hand dish soap in the machine makes foam that the drain pump moves badly. If the tub had suds in it, run a rinse cycle with nothing added and try again before buying anything.
What a technician will look at
Described so you know what you are paying for, not as steps to repeat.
Test the drain pump and the pressure sensor
Current GE machines drain with a separate pump and watch the level with a pressure sensor in the sump. A pump that hums and moves nothing is jammed or dead; a sensor fouled with grease reports water that is not there. Both are reached from underneath with the machine out.
When to call a technician
When the filters and sump are clean, the hose runs properly with a high loop, the disposal and air gap are clear, and FTD still returns. From that point the fault is inside the machine rather than in the plumbing around it.
What the repair costs
| Repair | Part only | Fitted by a technician |
|---|---|---|
| Punching out the disposal plug, clearing filters and sump | - | Free |
| Diagnosis alone | - | $70 to $130 |
| Pressure sensor replacement | $15 to $30 | $100 to $200 |
| Drain pump replacement | $50 to $100 | $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
- Not enough water arrived in the time the machine allows for filling.
H2O
- On machines with Floor Protect with Alert, water has reached the sensor in the base pan. On the entry models without it, the control has locked and wants a reset.
999
- The machine will not drain at all: the control asked for a pump-out and nothing happened.
C3
Questions people ask
- Does FTD mean flood detected?
- No, and that mistake is on several sites. FTD is failure to drain. A leak on these machines shows as 999 or LEAK DETECTED, which is a different page.
- Where is F56 from?
- Some models report the drain timeout as F56 rather than FTD. The meaning and the checks are identical.
- What is PrS, which I also saw?
- The pressure sensor reporting a signal the control cannot read at all, rather than a level it disagrees with. It is the same part that FTD and H2O depend on, and the same technician visit.
Which machines this applies to
Applies to
Current GE, GE Profile and Café dishwashers: GDT, GDF, GDP, PDT, PDP and CDT models from about 2013 onward. F56 is the same fault on some models. Older machines show C1, C2 or C3 instead.
Last checked
2026-08-28