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WILLIS heat pumps: how do their ratings compare?

A typical WILLIS heat pump beats 63% of similar heat pumps (same size and type), which is well above average. WILLIS has 29 heat pump models in this list.

Covers heat pumps sold new today (R-454B and R-32 refrigerant). See older R-410A models · Updated

Overall score

63%

of similar heat pumps beaten by its typical model

Well above average

WILLIS has no QMID (the manufacturer ID the 25C tax credit needs) on file, so it is not ranked against other brands. Based on 42 models with every rating.

WILLIS, rating by ratingStrongest on hot-day cooling efficiency (beats 72%), weakest on efficiency on a 5°f day (beats 44%).
  • Efficiency on a 5°F dayCOP at 5°FBeats 44%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FBeats 71%
  • Winter-long heating efficiencyHSPF2Beats 50%
  • Summer-long cooling efficiencySEER2Beats 69%
  • Hot-day cooling efficiencyEER2Beats 72%

Average (50%)

Each bar: the share of similar heat pumps a typical model beats on that rating.

Want WILLIS’s ranks and its models inside every size class? Switch to Advanced

Rebate standards

Share of this brand’s models that meet the efficiency levels rebate programs use. Programs can have other rules too.

  • 97%

    meet CEE 2025 Tier 1, the level many utility rebates use.

    28 models. All brands: 57%.

    See them

  • 97%

    meet Xcel Energy Colorado’s cold-climate rebate levels.

    28 models. All brands: 53%.

    See them

  • 10%

    reach the cold-climate tier: full heating output and a COP of 2.1 or more at 5°F.

    3 models. All brands: 3%.

    See them

WILLIS all-around best, by size

Balances heating (5°F output and efficiency, HSPF2) and cooling (SEER2, EER2), each rating against units their size.

Showing Ducted, 3.5–4.5 tons (39,000–56,999 Btu/h cooling). What size is my system?

3 of WILLIS’s 3 models of this size and type have all five ratings.

  1. 1FLEX48KUHR32with ducted air handler FLEXAH48KR32WILLISAlso listed as FLEX60KUHR324 tons · 48,000 Btu/h · DuctedCold-climate pick, score 78.9Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    100% (Capacity at 5°F vs 47°F)
    Top 10%
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Winter efficiency
    10.0 (HSPF2)
    Great
    Cooling efficiency
    19.0 (SEER2)
    Great
    Hot-day cooling
    12.0 (EER2)
    Great
    83.1score / 100Heating 79 · Cooling 87
  2. 2MZUHW42KR32-OWILLIS3.5 tons · 42,000 Btu/h · DuctedCold-climate pick, score 55.7Meets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    86% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.90 (COP at 5°F)
    Below the middle
    Winter efficiency
    8.1 (HSPF2)
    Good
    Cooling efficiency
    18.0 (SEER2)
    Great
    Hot-day cooling
    12.0 (EER2)
    Great
    69.1score / 100Heating 56 · Cooling 83

These are certified test ratings, not a recommendation for your home. The right size comes from a load calculation by a contractor.

What to do next

The advanced view has WILLIS’s ranks on each rating, its models inside every size and type, cold-weather curves and its newest certifications.

Open the advanced view