KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave F1 Error Fix: Oven Cavity Thermistor Open/Shorted

The internal cavity temperature sensor has failed (open or shorted circuit). This sensor is used for sensor (auto) cook functions. Without a working sensor, auto-cook and sensor-reheat modes will not function. Manual time/power cooking still works. Check sensor wiring and connector. Replace thermistor if defective.

Medium severity2 fixes available✨ Free fix available

Quick Answer

Error F1 on the KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave means: Oven Cavity Thermistor Open/Shorted. The top-ranked community fix is “Replace Oven Cavity Thermistor Sensor” (medium difficulty, ~30 min, DIY cost: $15-$25). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · microwave

Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.

When to Call a Professional

While many microwave repairs can be done safely at home, consider hiring a qualified technician if:

The repair involves electrical wiring, gas lines, or refrigerant
You've tried the top-ranked fix and the error persists
You smell gas, see sparking, or notice water leaking
The repair requires specialized tools you don't have
Your appliance is still under manufacturer warranty

Average professional repair cost for this issue: $130-$190.

Other KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave Error Codes

ARCING INSIDE

Arcing / Sparking Inside Cavity

2 fixes

DOOR LATCH BROKEN

Door Latch / Handle Broken

2 fixes

Shortkey / Keypad Shorted

2 fixes

Touchpad / Keypad Open Circuit

2 fixes

Control Board Failure

2 fixes

FAN NOISY

OTR Exhaust Fan Noisy or Weak

2 fixes

LIGHT OUT

Interior Light Not Working

2 fixes

Sensor Error — Humidity Sensor

2 fixes

People Also Ask About KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave Error F1

What does error code F1 mean on a KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave?

Error code F1 on the KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave means: Oven Cavity Thermistor Open/Shorted. The internal cavity temperature sensor has failed (open or shorted circuit). This sensor is used for sensor (auto) cook functions. Without a working sensor, auto-cook and sensor-reheat modes will not function. Manual time/power cooking still works. Check sensor wiring and connector. Replace thermistor if defective.

How do I fix error code F1 on my KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave?

The most successful fix is "Replace Oven Cavity Thermistor Sensor" (medium difficulty, ~30 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

Is error code F1 on a KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave serious?

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Can I fix KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave error F1 myself?

Yes — the top-ranked community fix ("Replace Oven Cavity Thermistor Sensor") is rated medium difficulty and takes about 30 minutes. Tools needed: Phillips screwdriver, Multimeter.

How much does it cost to repair KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave error F1?

DIY cost: $15-$25. Professional repair typically costs $130-$190. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave have?

The KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave has 8 other known error codes, including: ARCING INSIDE (Arcing / Sparking Inside Cavity), DOOR LATCH BROKEN (Door Latch / Handle Broken), F2 (Shortkey / Keypad Shorted), F3 (Touchpad / Keypad Open Circuit), F5 (Control Board Failure), and 3 more.

What other error codes does the KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave have?

The KitchenAid KMHS120ESS 30 in. 1000-Watt Over-the-Range Microwave has 8 other known error codes:

ARCING INSIDE — Arcing / Sparking Inside Cavity (2 fixes)
DOOR LATCH BROKEN — Door Latch / Handle Broken (2 fixes)
F2 — Shortkey / Keypad Shorted (2 fixes)
F3 — Touchpad / Keypad Open Circuit (2 fixes)
F5 — Control Board Failure (2 fixes)
FAN NOISY — OTR Exhaust Fan Noisy or Weak (2 fixes)
LIGHT OUT — Interior Light Not Working (2 fixes)
SE — Sensor Error — Humidity Sensor (2 fixes)

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