Willis Heat Pump Manuals
Select your Willis model number below for installation steps, settings, maintenance schedules, troubleshooting and the full specification sheet. Your model number is printed on the rating plate on the side of the outdoor unit.
Willis heat pumps by model number
| Model | Description | Certified |
|---|---|---|
| AUHW09KR32-OULTIMA | 9,100 Btu/h ductless mini-split heat pump | June 2026 |
| AUHW12KR32-OULTIMA | 12,000 Btu/h ductless mini-split heat pump | May 2026 |
| AUHW18KR32-OULTIMA | 18,000 Btu/h ductless mini-split heat pump | March 2026 |
| AUHW24KR32-OULTIMA | 22,000 Btu/h ductless mini-split heat pump | November 2025 |
| CHW09KAR32-OCharmo | 9,100 Btu/h ductless mini-split heat pump | March 2026 |
| CHW12KCH18S2-OCharmo | 12,000 Btu/h ductless mini-split heat pump | June 2026 |
| CHW12KR32-OCharmo | 12,000 Btu/h ductless mini-split heat pump | March 2026 |
| CHW18KR32-OCharmo | 18,000 Btu/h ductless mini-split heat pump | January 2026 |
| CHW24KR32-OCharmo | 24,000 Btu/h ductless mini-split heat pump | June 2026 |
| CHW30KR32-OCharmo | 30,000 Btu/h ductless mini-split heat pump | March 2026 |
| CHW36KR32-OCharmo | 33,600 Btu/h ductless mini-split heat pump | March 2026 |
| FLEX24/36KUHFLEXX High-efficiency Series | 3-ton split-system heat pump | June 2026 |
| FLEX24KUHR32FLEXX R32 | 2-ton split-system heat pump | September 2026 |
| FLEX36KUHR32FLEXX R32 | 2-ton split-system heat pump | September 2026 |
| FLEX48/60KUHFLEXX High-efficiency Series | 4.5-ton split-system heat pump | July 2026 |
| FLEX48KUHR32FLEXX R32 | 4-ton split-system heat pump | September 2026 |
| FLEX60KUHR32FLEXX R32 | 4-ton split-system heat pump | September 2026 |
| HW-COND36KHi-PRO HD | 2.5-ton split-system heat pump | April 2026 |
| MZUHW18KCH21S2-OMultiHeat | 17,000 Btu/h ductless mini-split heat pump | June 2026 |
| MZUHW18KR32-OMULTI HEAT | 18,000 Btu/h ductless mini-split heat pump | March 2026 |
| MZUHW24KCH21S2-OMultiHeat | 23,200 Btu/h ductless mini-split heat pump | June 2026 |
| MZUHW24KR32-OMULTI HEAT | 24,000 Btu/h ductless mini-split heat pump | March 2026 |
| MZUHW30KCH21S2-OMultiHeat | 28,400 Btu/h ductless mini-split heat pump | June 2026 |
| MZUHW30KR32-OMULTI HEAT | 28,400 Btu/h ductless mini-split heat pump | March 2026 |
| MZUHW36KCH21S2-OMultiHeat | 34,000 Btu/h ductless mini-split heat pump | June 2026 |
| MZUHW36KR32-OMULTI HEAT | 36,000 Btu/h ductless mini-split heat pump | March 2026 |
| MZUHW42KCH21S2-OMultiHeat | 36,000 Btu/h ductless mini-split heat pump | June 2026 |
| MZUHW42KR32-OMULTI HEAT | 42,000 Btu/h ductless mini-split heat pump | March 2026 |
| PRT60KUHUltra Heat Rooftop Series | 4.5-ton packaged heat pump | June 2026 |
| PUHW09KR32-OHEATFINITY | 9,100 Btu/h ductless mini-split heat pump | March 2026 |
| PUHW12KCH24S2-OHeatfinity | 12,000 Btu/h ductless mini-split heat pump | June 2026 |
| PUHW12KR32-OAll MATCH | 12,000 Btu/h ductless mini-split heat pump | March 2026 |
| PUHW18KCH23S2-OHeatfinity | 18,000 Btu/h ductless mini-split heat pump | June 2026 |
| PUHW18KR32-OHEATFINITY | 18,000 Btu/h ductless mini-split heat pump | March 2026 |
| PUHW24KR32-OHEATFINITY | 22,000 Btu/h ductless mini-split heat pump | November 2025 |
| PUHW36KR32-OCENTURION | 33,600 Btu/h ductless mini-split heat pump | March 2026 |