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York · YZF42B21S LX Series AC

York YZF42B21S LX Series AC EC Error Fix: Outdoor Coil Sensor Open Circuit

The outdoor coil temperature sensor circuit is open or disconnected. This causes inaccurate temperature readings and may cause system faults or shutdown.

Medium severity2 fixes available

Quick Answer

Error EC on the York YZF42B21S LX Series AC means: Outdoor Coil Sensor Open Circuit. The top-ranked community fix is “Replace Outdoor Coil Temperature Sensor” (medium difficulty, ~35 min, DIY cost: $25-$40). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · air conditioner

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.

Root Cause Analysis

Sensor MalfunctionPrimary

When to Call a Professional

While many air conditioner 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 York Models with Error EC

DERA-F036N07 14 SEER

air_conditioner · 2 fixes

Other York YZF42B21S LX Series AC Error Codes

Indoor Temperature Sensor Failure

2 fixes

Outdoor Coil Temperature Sensor Fault

2 fixes

High Pressure Switch Trip

2 fixes

Low Pressure Switch Trip

2 fixes

Compressor Overcurrent Protection

2 fixes

Indoor Fan Motor Locked Rotor

2 fixes

Outdoor Fan Motor Locked Rotor

2 fixes

Indoor Coil Freeze Protection Activated

2 fixes

People Also Ask About York YZF42B21S LX Series AC Error EC

What does error code EC mean on a York YZF42B21S LX Series AC?

Error code EC on the York YZF42B21S LX Series AC means: Outdoor Coil Sensor Open Circuit. The outdoor coil temperature sensor circuit is open or disconnected. This causes inaccurate temperature readings and may cause system faults or shutdown.

How do I fix error code EC on my York YZF42B21S LX Series AC?

The most successful fix is "Replace Outdoor Coil Temperature Sensor" (medium difficulty, ~35 minutes). Estimated DIY cost: $25-$40. HomeMD has 2 community-ranked fixes for this error.

Is error code EC on a York YZF42B21S LX Series AC 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 York YZF42B21S LX Series AC error EC myself?

Yes — the top-ranked community fix ("Replace Outdoor Coil Temperature Sensor") is rated medium difficulty and takes about 35 minutes. Tools needed: Phillips screwdriver, Multimeter.

How much does it cost to repair York YZF42B21S LX Series AC error EC?

DIY cost: $25-$40. Professional repair typically costs $130-$190. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the York YZF42B21S LX Series AC have?

The York YZF42B21S LX Series AC has 8 other known error codes, including: E1 (Indoor Temperature Sensor Failure), E2 (Outdoor Coil Temperature Sensor Fault), E3 (High Pressure Switch Trip), E4 (Low Pressure Switch Trip), E5 (Compressor Overcurrent Protection), and 3 more.

Which other York models have the EC error?

Error code EC also appears on 1 other York model: DERA-F036N07 14 SEER. The fix may vary by model, so check each model's specific page for tailored repair steps.

What other error codes does the York YZF42B21S LX Series AC have?

The York YZF42B21S LX Series AC has 8 other known error codes:

E1 — Indoor Temperature Sensor Failure (2 fixes)
E2 — Outdoor Coil Temperature Sensor Fault (2 fixes)
E3 — High Pressure Switch Trip (2 fixes)
E4 — Low Pressure Switch Trip (2 fixes)
E5 — Compressor Overcurrent Protection (2 fixes)
E6 — Indoor Fan Motor Locked Rotor (2 fixes)
E7 — Outdoor Fan Motor Locked Rotor (2 fixes)
E8 — Indoor Coil Freeze Protection Activated (2 fixes)

Which other York models have the EC error?

Error code EC also appears on 1 other York model:

DERA-F036N07 14 SEER (air conditioner) · 2 fixes

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