What to check yourself
Step 1. Clear the air gap on the sink
This is where GE itself sends you first, and for good reason. The small chrome cylinder next to the tap has a cap that twists off and a cover that lifts out, and underneath there is usually a plug of grey sludge. It narrows the outlet slowly, so the machine drains a little worse every month until it trips the timer.
Step 2. Run the garbage disposal, then check its inlet
A disposal half full of food narrows the dishwasher outlet as well. Run it with the tap on for half a minute. If the disposal is new, look for the plastic knockout plug in the dishwasher spigot: if it was never punched out, the machine has been draining through nothing and this code was inevitable.
Step 3. Follow the drain hose
Pull the machine forward enough to see the hose. A kink behind the machine, or a hose crushed under something in the cabinet, gives exactly this slow drain. Check the high loop too: the hose should rise to counter height before it drops to the drain.
Step 4. Clear the sump under the filter
Lower rack out, filter out, and look into the well with a torch. Rice, seeds and glass collect on the drain side and slow the flow without stopping it, which is precisely what C1 describes.
Feel for glass before you reach in.
What a technician will look at
Described so you know what you are paying for, not as steps to repeat.
Test the drain valve and pump
On these older GE machines the wash motor also drains, through a valve opened by a solenoid. A valve that only half opens, or a check ball that sticks, gives a slow drain that no amount of cleaning outside the machine will fix. The technician meters the solenoid and looks at the valve with the machine out.
When to call a technician
When the air gap, disposal, hose and sump are all clear and C1 still comes back. What remains is inside the machine under the tub, and on this design it is usually the drain valve rather than a pump.
What the repair costs
| Repair | Part only | Fitted by a technician |
|---|---|---|
| Clearing the air gap, disposal and sump | - | Free |
| Diagnosis alone | - | $70 to $130 |
| Drain solenoid or valve replacement | $25 to $60 | $150 to $325 |
| 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
Questions people ask
- My manual does not list C1 at all. Is the display broken?
- No. GE wrote the C codes for its technicians, and the owner's manuals of that era never printed them. The code is real and means what this page says.
- It drains fine when I run the disposal first. Is that a fix?
- It is a diagnosis. The disposal is the restriction. Clean it out properly and check that the dishwasher inlet on it is clear, and the code should stop.
Which machines this applies to
Applies to
Older GE, GE Profile and Hotpoint dishwashers with electronic controls: GSD, GHD, PDW, EDW, GLD and HDA model prefixes. Current GDT, GDF and PDT models show FTD for the same fault.
Last checked
2026-08-28