What to check yourself
Step 1. Tap the float cover
GE's own first step. Front left corner of the tub floor there is a plastic dome the shape of an upturned cup. The float underneath it is what tells the machine the tub is full. Tap the dome a few times and lift it: a float held down by a seed, a bit of glass or a fork tine cannot rise, and the fill never stops.
Step 2. Check whether there was a power cut
The code names it directly: a machine that loses power mid-fill and then restarts can fill a second time on top of the first. If the lights in the house flickered, press Start and then Cancel to drain, and run the cycle again. If C4 does not return, that was the whole story.
Step 3. Clear the sump at the back of the tub floor
The drain sump looks like an upturned silverware basket at the back. If it is packed with debris, the machine does not empty properly between fills, the next fill lands on top of what stayed behind, and the float trips. Clear it, then look at the drain outlet as well.
Glass collects here. Look first.
What a technician will look at
Described so you know what you are paying for, not as steps to repeat.
Test the float switch
If the float moves freely but the fill still runs on, the switch under it has failed. It is a cheap microswitch reached from below the tub floor, and the technician meters it while lifting the float.
Check the inlet valve for closing
Rarer, and the one to check when the float and switch are both good: an inlet valve that lets water dribble through when it is off. The tell is a tub that has water in it after sitting unused for a day.
When to call a technician
When the float moves freely, the sump is clear and there was no power cut, yet C4 comes back. The float switch and the inlet valve are both simple parts, but the risk of getting it wrong is a flooded kitchen, which is why this one is worth a visit.
What the repair costs
| Repair | Part only | Fitted by a technician |
|---|---|---|
| Freeing the float and clearing the sump | - | Free |
| Diagnosis alone | - | $70 to $130 |
| Float switch replacement | $9 to $25 | $100 to $200 |
| Inlet valve replacement | $30 to $70 | $80 to $170 |
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
- C4 is showing but the tub is empty. How can it be overfilled?
- Because the code is about what the float reported, not what you see. A float stuck up says full when the tub is dry. Tap the dome, lift the float and let it drop, and the report usually corrects itself.
- Is C4 the same as C5?
- Opposite. C4 is too much water or a float that did not rise. C5 is too little water, a pump-out over almost before it began. Both live at the float, which is why they get confused.
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. Seen on machines back to around 1990.
Last checked
2026-08-28