🌡️Heat Pump

ALERT 22

Lennox · XP21 Dave Lennox Signature Collection 20 SEER Heat Pump

Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump ALERT 22 Error Fix: Compressor Short-Cycle Protection Active

The compressor is in its minimum off-time delay (typically 5 minutes) to allow refrigerant pressure equalization. This is a normal protective function, not a fault. If this alert appears continuously, check for rapid thermostat cycling, short cycling from a refrigerant issue, or an oversized system.

Low severity2 fixes available✨ Free fix available

Quick Answer

Error ALERT 22 on the Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump means: Compressor Short-Cycle Protection Active. The top-ranked community fix is “Inspect Refrigerant Levels and System Sizing” (medium difficulty, ~60 min, DIY cost: $0-$20). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · heat pump

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 heat pump 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: $150-$300.

Other Lennox Models with Error ALERT 22

XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner

air_conditioner · 2 fixes

XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner

air_conditioner · 2 fixes

XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump

heat_pump · 2 fixes

Other Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump Error Codes

1 FLASH YELLOW

High Pressure Switch Open

2 fixes

2 FLASHES YELLOW

Low Pressure Switch Open

2 fixes

3 FLASHES YELLOW

Compressor Thermal Overload

2 fixes

4 FLASHES YELLOW

Short-Cycle Protection

2 fixes

ALERT 1

Communication Loss — Outdoor Unit

2 fixes

ALERT 11

High Pressure Protection — Outdoor Unit

2 fixes

ALERT 12

Low Pressure Protection — Outdoor Unit

2 fixes

ALERT 14

Compressor Discharge Temperature High

2 fixes

People Also Ask About Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump Error ALERT 22

What does error code ALERT 22 mean on a Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump?

Error code ALERT 22 on the Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump means: Compressor Short-Cycle Protection Active. The compressor is in its minimum off-time delay (typically 5 minutes) to allow refrigerant pressure equalization. This is a normal protective function, not a fault. If this alert appears continuously, check for rapid thermostat cycling, short cycling from a refrigerant issue, or an oversized system.

How do I fix error code ALERT 22 on my Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump?

The most successful fix is "Inspect Refrigerant Levels and System Sizing" (medium difficulty, ~60 minutes). Estimated DIY cost: $0-$20. HomeMD has 2 community-ranked fixes for this error.

Is error code ALERT 22 on a Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump serious?

This error is rated low severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Can I fix Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump error ALERT 22 myself?

Yes — the top-ranked community fix ("Inspect Refrigerant Levels and System Sizing") is rated medium difficulty and takes about 60 minutes. Tools needed: Refrigerant manifold gauge set, Vacuum pump (if needed).

How much does it cost to repair Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump error ALERT 22?

DIY cost: $0-$20. Professional repair typically costs $150-$300. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump have?

The Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump has 8 other known error codes, including: 1 FLASH YELLOW (High Pressure Switch Open), 2 FLASHES YELLOW (Low Pressure Switch Open), 3 FLASHES YELLOW (Compressor Thermal Overload), 4 FLASHES YELLOW (Short-Cycle Protection), ALERT 1 (Communication Loss — Outdoor Unit), and 3 more.

Which other Lennox models have the ALERT 22 error?

Error code ALERT 22 also appears on 3 other Lennox models: XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner, XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner, XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump. The fix may vary by model, so check each model's specific page for tailored repair steps.

What other error codes does the Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump have?

The Lennox XP21 Dave Lennox Signature Collection 20 SEER Heat Pump has 8 other known error codes:

1 FLASH YELLOW — High Pressure Switch Open (2 fixes)
2 FLASHES YELLOW — Low Pressure Switch Open (2 fixes)
3 FLASHES YELLOW — Compressor Thermal Overload (2 fixes)
4 FLASHES YELLOW — Short-Cycle Protection (2 fixes)
ALERT 1 — Communication Loss — Outdoor Unit (2 fixes)
ALERT 11 — High Pressure Protection — Outdoor Unit (2 fixes)
ALERT 12 — Low Pressure Protection — Outdoor Unit (2 fixes)
ALERT 14 — Compressor Discharge Temperature High (2 fixes)

Which other Lennox models have the ALERT 22 error?

Error code ALERT 22 also appears on 3 other Lennox models:

XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner (air conditioner) · 2 fixes
XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner (air conditioner) · 2 fixes
XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump (heat pump) · 2 fixes

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