What C4 Means
GE describes C4 as the machine having filled twice after a power failure, with a stuck or failed float switch or a clogged drain or sump behind it. The float is the safety device that tells the control the tub is full; if it sticks, the dishwasher can keep taking water when it should have stopped, which is why this one is worth dealing with promptly rather than ignoring.
Common Causes of C4
- Float dome stuck up or down by debris or detergent residue
- Failed float switch
- Sump or drain clogged so water is not leaving the tub
- Water inlet valve not closing fully
🔧 One Safe Check You Can Try
GE's own steps come first: touch START then CANCEL/RESET, and tap the float cover - the small plastic dome inside the tub - to free it if it is stuck. Check the sump area at the bottom of the tub for debris, broken glass or a stray utensil, with the dishwasher switched off and using a torch rather than bare fingers. If the code returns after that, stop and book service, and close the dishwasher's water shut-off if you see any sign of overfilling.
⚠ Why You Shouldn't Go Further Than That
- None for tapping the float cover and inspecting the sump - GE lists both as owner steps.
- An inlet valve that will not close is a flooding risk and needs the water and power isolated before it is touched.
- Damage caused during a repair attempt may not be covered - check your warranty terms first.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.