Willis / AIR-SOURCE HEAT PUMP
FLEX48/60KUH
FLEXX High-efficiency Series · EPA record 3544274
Source checked Sep 21, 2026
Performance & equipment details
Values below belong to EPA record 3544274. Temperature points and test metrics are preserved as reported. Missing and zero values are not substituted with estimates.
| Metric or attribute | Source value |
|---|---|
| SEER2 · BTU/Wh | 16.00 |
| EER2 · BTU/Wh | 10.00 |
| HSPF2 · BTU/Wh | 9.00 |
| Cooling capacity · BTU/h | 54000 |
| Heating capacity at 47°F / 8.3°C · BTU/h | 54000 |
| Heating capacity at 17°F / −8.3°C · BTU/h | 44000 |
| Heating capacity at 5°F / −15°C · BTU/h | 41000 |
| COP at 5°F / −15°C | 1.80 |
| Equipment / loop type | HP - Split System |
| Refrigerant / source-reported GWP | R-410A (GWP:2088) |
| Compressor staging | Continuously variable |
| Connected capability | No |
This listed system
These ratings apply to the listed configuration. Changing a component may change performance.
Outdoor unit
+FLEX48/60KUHIndoor unit
FLEXAH48/60KAHRI reference 214797686 · reported by ENERGY STAR; no direct AHRI data connection.
All source records for FLEX48/60KUH →Specifications & provenance
Every value below is preserved from the source record. Checked Sep 21, 2026. Asterisks and other model wildcards are retained as published.
| Source field | Reported value | Evidence |
|---|---|---|
| pd id | 3544274 | EPA Sep 21, 2026 |
| markets | United States, Canada | EPA Sep 21, 2026 |
| cop at 5 f | 1.80 | EPA Sep 21, 2026 |
| eer2 btu wh | 10.00 | EPA Sep 21, 2026 |
| series name | FLEXX High-efficiency Series | EPA Sep 21, 2026 |
| cold climate | Yes | EPA Sep 21, 2026 |
| hspf2 btu wh | 9.00 | EPA Sep 21, 2026 |
| model number | FLEX48/60KUH | EPA Sep 21, 2026 |
| product type | HP - Split System | EPA Sep 21, 2026 |
| seer2 btu wh | 16.00 | EPA Sep 21, 2026 |
| date certified | 2026-07-07T00:00:00.000 | EPA Sep 21, 2026 |
| manufacturer type | System Manufacturer | EPA Sep 21, 2026 |
| compressor staging | Continuously variable | EPA Sep 21, 2026 |
| energy star partner | 4435273 Canada Inc | EPA Sep 21, 2026 |
| connected capability | No | EPA Sep 21, 2026 |
| refrigerant with gwp | R-410A (GWP:2088) | EPA Sep 21, 2026 |
| ahri reference number | 214797686 | EPA Sep 21, 2026 |
| cooling capacity btu h | 54000 | EPA Sep 21, 2026 |
| outdoor unit brand name | Willis | EPA Sep 21, 2026 |
| date available on market | 2024-06-05T00:00:00.000 | EPA Sep 21, 2026 |
| indoor unit model number | FLEXAH48/60K | EPA Sep 21, 2026 |
| installation capabilities | None | EPA Sep 21, 2026 |
| energy star model identifier | ES_1128541_FLEX48/60KUH_06042024223004_7193164 | EPA Sep 21, 2026 |
| heating capacity at 5 f btu h | 41000 | EPA Sep 21, 2026 |
| meets most efficient criteria | Yes | EPA Sep 21, 2026 |
| heating capacity at 17 f btu h | 44000 | EPA Sep 21, 2026 |
| heating capacity at 47 f btu h | 54000 | EPA Sep 21, 2026 |
| meets peak cooling requirements | No | EPA Sep 21, 2026 |
| controls verification procedure cvp test | ENERGY STAR CVP Test | EPA Sep 21, 2026 |