TK'S vs WILLIS: heat pump ratings compared
Against heat pumps of the same size and type, a typical TK'S model beats 48% and a typical WILLIS model 51%. WILLIS rates slightly higher overall.
Covers older R-410A heat pumps, no longer installed new. See models sold today · Updated
TK'S
48%
of similar heat pumps beaten by its typical model
About average15 models listed
WILLIS
51%
of similar heat pumps beaten by its typical model
About average15 models listed
- Efficiency on a 5°F dayCOP at 5°FTK'S: Beats 34%WILLIS: Beats 39%
- Heating power kept at 5°FCapacity at 5°F vs 47°FTK'S: Beats 31%WILLIS: Beats 64%
- Winter-long heating efficiencyHSPF2TK'S: Beats 58%WILLIS: Beats 52%
- Summer-long cooling efficiencySEER2TK'S: Beats 64%WILLIS: Beats 55%
- Hot-day cooling efficiencyEER2TK'S: Beats 47%WILLIS: Beats 46%
Average (50%)Dashed outline: the other brand, for comparison
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Rebate standards
CEE 2025
- TK'S
- 67%
- WILLIS
- 87%
Xcel CC
- TK'S
- 20%
- WILLIS
- 87%
CEE Advanced
- TK'S
- 0%
- WILLIS
- 0%
ENERGY STAR CC
- TK'S
- 0%
- WILLIS
- 73%
Top cold-climate picks, ductless 3.5–4.5 tons
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 Ductless, 3.5–4.5 tons (39,000–56,999 Btu/h cooling). What size is my system?
TK'S
None of TK'S’s ductless, 3.5–4.5 tons models qualifies.
WILLIS
No ductless, 3.5–4.5 tons model from WILLIS.
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.
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