GE Dishwasher C4 — What It Means & How to Fix It

By Callum Griffin · Researched and verified against manufacturer and repair documentation · Reviewed June 2026

C4 means the dishwasher refilled twice after a power interruption, which usually traces to a stuck overfill float or a clogged sump rather than anything electrical.

What this code means

C4 is set when the machine detects it has filled twice following a power failure, a pattern that points at the float system. The overfill float — a plastic cover like an upside-down cup in the front-left corner of the tub floor — can stick and make the control misjudge the water level, and debris around the sump at the back of the tub can confuse the same logic. GE's guidance is to reset, free the float, and check the sump before suspecting anything deeper.

C4 ties to the float and fill logic on GE's C-code dishwashers. Float placement is consistent — the front-left corner of the tub floor — but if your model labels this fault differently, its manual is the authority.

Most likely causes

CauseHow likelyDIY-fixable?
Overfill float stuck in the raised position Common Yes — tap it free
Debris around the sump at the rear tub floor Common Yes — inspect and clear
Cycle interrupted by a power failure Occasional Yes — reset and restart
Float switch or water-level sensor faulty Less common No — technician job

What you can try yourself

  1. Press Start, then Cancel/Reset, to clear the doubled-fill state GE flags with C4.
  2. Find the float cover — the upside-down-cup shape in the front-left corner of the tub floor — and tap it gently up and down to free any sticking; it should rise and drop back freely.
  3. Look at the sump at the back-bottom of the tub, which resembles an upside-down silverware basket, and clear any debris caught around it.
  4. Wipe detergent scale or grit from around the float so it seats cleanly, then restore power.
  5. Run a short cycle and watch that the fill stops at a normal level instead of running on.

When to call a technician

Typical professional repair cost: Freeing the float costs nothing. A float switch or water-level sensor replacement runs roughly $130–$250 with labor.

Frequently asked questions

Where is the float on a GE dishwasher?

It's in the front-left corner of the tub floor — a small plastic cover shaped like an upside-down cup. It rises with the water level to tell the control when to stop filling, and tapping it up and down frees it if it has stuck.

Why did C4 appear after a power cut?

C4 specifically flags that the dishwasher filled twice after a power interruption, which the control reads as a float or level problem. Often it is just the interrupted cycle plus a slightly sticky float, and a reset and a tap on the float clear it.

Could C4 cause a leak?

If the float genuinely sticks and the machine overfills, water can eventually reach the door. That is why freeing or replacing a faulty float matters — but the C4 code itself is the control catching the problem, usually before it gets that far.

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