Not heating: Codes, Causes & Fixes
When a dishwasher, washer, dryer or oven runs but doesn't heat, the usual suspects are the heating element, the temperature sensor (thermistor) that controls it, a safety thermal fuse or – in dryers – restricted airflow that trips the overheat protection. Error codes often distinguish between a sensor fault and a heater circuit fault, which helps decide what to test. Heating elements run on mains voltage, so replacement is a job for a technician unless you are qualified; for boilers see “No heat or hot water”.
71Codes
3.0Average severity
17%High or critical
41%DIY-friendly
Severity distribution
Most viewed
U4
Daikin · Air Conditioner / Heat Pump
The indoor unit has lost its data link with the outdoor unit, so the system can't cool or heat.
Moderate
E6
Mitsubishi Electric · Air Conditioner / Heat Pump
The indoor unit isn't getting valid signals back from the outdoor unit over the S3 wire.
Moderate
D80
LG · Dryer
LG Flow Sense detected restricted airflow in the vent. The dryer still runs, but lint buildup…
Moderate
HE
Samsung · Dryer
The Samsung dryer isn’t heating as expected – often no heat at all. Check power, gas supply…
Moderate
F2
GE Appliances · Oven / Range
The control saw the oven running hotter than its safety limit and shut the heat off.
High
F3
Whirlpool · Oven / Range
The control can't get a valid reading from the oven temperature sensor, so it won't heat…
Moderate