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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

Top WILLIS cold-climate picks, by size

Only units that keep at least 70% of their heat at 5°F, ranked on heat kept, efficiency at 5°F and seasonal efficiency (HSPF2), against units their size.

Showing Ducted, 2.5–3 tons (27,000–38,999 Btu/h cooling), the most-listed ducted size. Pick yours above. What size is my system?

4 of WILLIS’s 4 models of this size and type qualify.

  1. 1HW-COND36Kwith ducted air handler HW-AHU36KWILLIS2.5 tons · 32,000 Btu/h · DuctedKeeps 97% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    97% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    2.15 (COP at 5°F)
    Great
    Seasonal efficiency
    10.5 (HSPF2)
    Top 10%
    87.9score / 100
  2. 2FLEX36KUHR32with ducted air handler FLEXAH36KR32WILLIS3 tons · 34,000 Btu/h · DuctedKeeps 100% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    100% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    2.00 (COP at 5°F)
    Good
    Seasonal efficiency
    10.0 (HSPF2)
    Great
    76.9score / 100
  3. 3MZUHW36KR32-OWILLIS3 tons · 36,000 Btu/h · DuctedKeeps 92% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    92% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.90 (COP at 5°F)
    Below the middle
    Seasonal efficiency
    8.1 (HSPF2)
    Below the middle
    52.2score / 100
  4. 4MZUHW30KR32-OWILLIS2.5 tons · 28,400 Btu/h · DuctedKeeps 87% of its heat at 5°FMeets CEE 2025, CEE 2026, Xcel CC, ENERGY STAR CC
    Heat kept at 5°F
    87% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    1.88 (COP at 5°F)
    Below the middle
    Seasonal efficiency
    8.1 (HSPF2)
    Below the middle
    48.2score / 100

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.

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