Overview.
E1 means the dryer’s temperature-sensing circuit is open. The control can’t “see” the thermistor (temperature sensor), so it can’t regulate heat. You’ll often notice a flashing numeric display, short heat bursts followed by shutdown, or a cycle that runs cool and never finishes properly.
How the sensor works.
KitchenAid dryers use a thermistor (a heat-sensitive resistor) mounted on the exhaust duct or blower housing. As air temperature rises, the thermistor’s resistance changes; the control board reads that signal and adjusts heater power. When the circuit opens—because the sensor or its wiring breaks—the control interprets the reading as invalid and throws E1.
Likely causes (quick read): a failed thermistor, a loose/oxidized connector, a broken wire in the harness, or a damaged board input (rare compared to the first three).
Step-by-step diagnosis (safe and thorough)
1) Unplug the dryer.
Kill power first. Pull the model/serial from the door frame; you’ll need it for parts.
2) Find the thermistor and inspect.
Access the lower front or rear panel (varies by model). The thermistor sits on the exhaust duct or blower housing near the lint path. Look for cracked housings, singed plastic, or lint packed around the sensor.
3) Check connectors and harness.
Reseat the thermistor plug until it clicks. Inspect both the sensor leads and the harness back to the main board for nicks, pinched sections, or green/white oxidation on the terminals. A loose pin or oxidized blade can open the circuit under vibration.
4) Measure continuity/ohms (power still off).
Disconnect the two thermistor wires and read resistance with a multimeter. At room temperature the sensor should show a stable, finite resistance (not OL/open). If your meter shows open or the value jumps wildly when you gently flex the leads, the sensor or its pigtail is bad. If the sensor reads stable, check continuity from the sensor connector back to the control-board pins; a break in the harness will also produce E1.
5) Differentiate from other heat faults.
An open thermal fuse or high-limit thermostat usually stops heat but does not generate E1 on its own. If those safety devices are open, replace the failed device and fix the airflow/overheat cause, but continue to resolve the thermistor circuit that triggered E1.
Fix path that actually works
Start with the obvious: reseat and clean the thermistor connector and repair any damaged harness sections. If the thermistor reads open or erratic, replace it; this is the most common resolution. Only suspect the control board if you’ve confirmed a good thermistor and a good harness end-to-end yet the control still flags E1.
After installing a new sensor or repairing wiring, restore power and run a timed-dry test. The cycle should start heating normally without flashing the display. Watch the temperature behavior: the heater should cycle on/off as exhaust temperature rises and stabilizes.
Airflow matters
A brand-new thermistor can’t save a dryer with poor airflow. Clear the lint screen, vacuum the lint chute and blower housing, and check the vent from the dryer to the outside for kinks, crushed sections, or heavy lint buildup. Restricted airflow causes heat spikes, stresses sensors, and shortens the life of thermostats and fuses.
Safety notes
Don’t bypass the thermistor or run with jumpers “just to test”—you risk overheating and fire. Always unplug before opening panels, and avoid yanking on flat-flex or small-gauge leads; they break internally and create intermittent opens that are hard to trace.
When to call a pro
If the wiring disappears into tight harness bundles, if the connector pins look heat-damaged, or if E1 returns after a verified-good thermistor and harness, bring in a technician. A pro can load-test the circuit, check the control input properly, and confirm that temperature regulation behaves within spec under real airflow.