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First Co. vs WILLIS: heat pump ratings compared

Against heat pumps of the same size and type, a typical First Co. model beats 7% and a typical WILLIS model 51%. WILLIS rates higher overall.

Covers older R-410A heat pumps, no longer installed new. See models sold today · Updated

First Co.

7%

of similar heat pumps beaten by its typical model

Well below average

16 models listed

WILLIS

51%

of similar heat pumps beaten by its typical model

About average

15 models listed

Rating by ratingEach bar is the share of same-size, same-type heat pumps that a typical model beats, so the two brands compare fairly even if they make different sizes.
  • Efficiency on a 5°F dayCOP at 5°FFirst Co.: Beats 16%WILLIS: Beats 39%
  • Heating power kept at 5°FCapacity at 5°F vs 47°FFirst Co.: Beats 9%WILLIS: Beats 64%
  • Winter-long heating efficiencyHSPF2First Co.: Beats 2%WILLIS: Beats 52%
  • Summer-long cooling efficiencySEER2First Co.: Beats 1%WILLIS: Beats 55%
  • Hot-day cooling efficiencyEER2First Co.: Beats 10%WILLIS: Beats 46%

Average (50%)Dashed outline: the other brand, for comparison

Want ranks, distributions per size class and cold-weather curves? Switch to Advanced

Rebate standards

Share of each brand’s models that meet the level. Programs can have other rules too.

  • CEE 2025

    First Co.
    0%
    WILLIS
    87%

  • Xcel CC

    First Co.
    0%
    WILLIS
    87%

  • CEE Advanced

    First Co.
    0%
    WILLIS
    0%

  • ENERGY STAR CC

    First Co.
    0%
    WILLIS
    73%

All-around best, ducted 2.5–3 tons

Balances heating (5°F output and efficiency, HSPF2) and cooling (SEER2, EER2), each rating 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?

First Co.

No ducted, 2.5–3 tons model from First Co..

WILLIS

  1. 1MZUHW30KCH21S2-OWILLIS2.5 tons · 28,400 Btu/h · DuctedCold-climate pick, score 54.7Meets CEE 2025, CEE 2026, Xcel CC
    Heat kept at 5°F
    89% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.80 (COP at 5°F)
    Below the middle
    Winter efficiency
    8.1 (HSPF2)
    Below the middle
    Cooling efficiency
    16.0 (SEER2)
    Good
    Hot-day cooling
    11.0 (EER2)
    Below the middle
    53.1score / 100Heating 55 · Cooling 52
  2. 2MZUHW42KCH21S2-OWILLIS3 tons · 36,000 Btu/h · DuctedCold-climate pick, score 52.1Meets CEE 2025, CEE 2026, Xcel CC
    Heat kept at 5°F
    81% (Capacity at 5°F vs 47°F)
    Good
    Efficiency at 5°F
    1.84 (COP at 5°F)
    Below the middle
    Winter efficiency
    8.1 (HSPF2)
    Below the middle
    Cooling efficiency
    16.0 (SEER2)
    Good
    Hot-day cooling
    11.0 (EER2)
    Below the middle
    51.8score / 100Heating 52 · Cooling 52
  3. 3MZUHW36KCH21S2-OWILLIS3 tons · 34,000 Btu/h · DuctedCold-climate pick, score 50.8Meets CEE 2025, CEE 2026, Xcel CC
    Heat kept at 5°F
    83% (Capacity at 5°F vs 47°F)
    Great
    Efficiency at 5°F
    1.80 (COP at 5°F)
    Below the middle
    Winter efficiency
    8.1 (HSPF2)
    Below the middle
    Cooling efficiency
    16.0 (SEER2)
    Good
    Hot-day cooling
    11.0 (EER2)
    Below the middle
    51.1score / 100Heating 51 · Cooling 52

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

Next steps

The advanced view adds ranks, both brands’ models inside every size class, standout models per rating and cold-weather curves.

Open the advanced view