Miele Dishwasher Error Code F15

F15 indicates a water intake fault on the hot water connection, specifically that the incoming hot water temperature is below 100 degrees Fahrenheit. The code is an advisory notice and does not stop the dishwasher from completing its current program. It signals that the hot water supply should be inspected by a specialist to ensure proper water temperature is reaching the appliance.

Yes, the dishwasher continues operating normally when F15 appears and does not shut down the cycle. However, consistently low incoming water temperature can affect wash and sanitization performance since the machine uses incoming water temperature as part of its heating process. It is advisable to address the underlying hot water supply issue rather than ignore the code long term.

Repair costs vary widely depending on the cause. If the fix is as simple as adjusting the water heater thermostat, there may be no parts cost at all, though a service call fee from a plumber or technician could range from $75 to $150 or more. If the hot water inlet hose needs replacement or a plumbing correction is required, total costs could range from $100 to $400 or higher depending on labor rates and parts.

The first step is to have a plumber or qualified appliance specialist check the hot water supply line connected to the dishwasher. Verify that the water heater is set to an adequate temperature and that hot water is actually flowing to the hot water inlet rather than cold water. If the supply line is long, flushing the hot water at a nearby tap before running the dishwasher may help confirm whether heat loss in the pipe is the issue.

Resetting the dishwasher may clear the displayed code temporarily, but F15 will return if the root cause has not been corrected. Because the fault is tied to the actual temperature of incoming water, the code will continue appearing until the hot water supply consistently delivers water at or above 100 degrees Fahrenheit to the dishwasher inlet.