Whirlpool · Refrigerator
Whirlpool Refrigerator Error Code 28
Water inlet solenoid current too high
What this error means
Code 28 means the ice maker water inlet solenoid is drawing excessive current when energized. The module protects the driver circuit by logging code 28 and skipping fill.
How 28 is detected
When 28 appears on a Whirlpool refrigerator, the control board has confirmed that water did not leave the machine within the programmed drain window. On Whirlpool WRX735SDHZ, Whirlpool WRF555SDFZ, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most 28 calls are resolved without parts: inspect the fill tube above the ice maker for an ice plug—thaw with a warm towel. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If 28 returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Frozen fill tube causing back-pressure on the valve
- Shorted solenoid coil on the ice maker fill valve
- Mineral buildup restricting the valve pintle
- Module driver feeding voltage into a shorted harness
Step-by-step fixes
- 1Inspect the fill tube above the ice maker for an ice plug—thaw with a warm towel
- 2Disconnect power and measure fill valve coil resistance per the tech sheet
- 3Manually trigger a fill from diagnostics and watch for normal water stream into the mold
- 4Replace the ice maker fill valve if coil resistance is below spec
When to call a technician
If the valve tests good but code 28 persists, the ice maker module driver needs service replacement.
Affected models
- Whirlpool WRX735SDHZ
- Whirlpool WRF555SDFZ
- Whirlpool WRX986SIHZ
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use refrigerators to prevent 28 from lint and food debris buildup.
- Record when 28 appears in the cycle and whether it clears after a 60-second power reset on your Whirlpool refrigerator—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for 28; Whirlpool uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting 28; reversed plugs on pumps and valves cause immediate repeat faults.