Vitocal 100-AW

Total hydronic heat pump solution for heating, cooling, and domestic hot water

Residential air-to-water heat pump system featuring an outdoor unit, an indoor unit and a steel buffer tank (20 gal). Three sizes available: 1.5, 3.0 and 4.3 tons for cooling / 20.5, 34 and 58 MBH for heating.

Fast and simple installation
Energy efficient
Future ready with R32 low GWP refrigerant
Sustainable operation

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Highly efficient

Lower utility bills with efficiencies up to 4.9 COP and 16.8 EER.

Low cost of ownership

With minimal maintenance and low operating costs.

AIM Act ready

Achieves a global warming potential (GWP) under 700 kg CO2eq/kg Refrigerant

Flexible applications

Use for radiant heating, forced air, chilled panel and domestic hot water applications.

Quiet operation

Maximum sound level at 3 ft distance is between 52 - 56 dB, depending on model.

Installation ready

Each Vitocal 100-AW system comes with installation fittings included.

Vitocal 100-AW: The most accessible air-to-water heat pump solution in North America

The Vitocal 100-AW is a true "all-in-one kit" with an outdoor unit, indoor unit and buffer tank. This provides for a fast and simple installation. The kit can be delivered on a single pallet for easy inventory, delivery, and jobsite ease.  


The easiest way to add heat pump hot water

There is no reason to purchase a separate heat pump water heater with the available (optional) indirect-fired domestic storage tanks that save space and installation cost over other types of domestic hot water heating. The optional domestic indirect tanks come in two sizes. They are designed to pair with the Vitocal 100-AW, and the buffer tank can be physically mounted on top of the domestic tank to save space. A customer only needs to decide if they prefer 53 or 66 gallons of domestic hot water storage.


Simple set up and easy control

The indoor unit has an integrated controller that can be run with continuous pumping and outdoor reset using the included sensors (outdoor, indoor, and tank sensors) with no thermostat needed in what Viessmann calls a "European style" system; or set it up North American style with a third party thermostat or with third party zone controller directly wired to the dry contacts on the unit.


Flexible application types

Vitocal 100-AW works in a variety of application types. Whether you want forced air heating and cooling or you are retrofitting a legacy radiant heating system – or a mix of both, these systems easily adapt to different heating and cooling strategies.


Look inside the indoor unit

  1. Diverting valve
  2. System pump
  3. Electric heating element
  4. Controller
  5. Expansion tank
  6. Dual fuel switch
  7. Pump outputs

Look inside the outdoor unit

  1. Dynamically balanced fan blade
  2. Heavy gauge steel casing with baked enamel finish
  3. Pre-charged with R32 refrigerant
  4. Enhanced vapor injection (EVI) system
  5. Refrigerant to water brazed plate heat exchanger
  6. Robust inverter driven variable speed rotary compressor
  7. Large evaporator coil with corrosion-resistant coating
  8. Integrated control with Modbus for communication with indoor unit
Our goal: healthy homes, emission-free cities and a planet worth living on. Image: KeyFame /

Advantages of the Vitocal 100-AW

Fully electric low temperature heating with an output range of 20.5, 34.0 and 58.0 MBH for heating and 1.5, 3.0, and 4.3 tons for cooling.
Indoor unit comes with integrated system pump and a digital controller with outdoor reset logic.
Suitable for both new construction and retrofit projects.
Pairs with Vitocell 100-V indirect-fired domestic hot water tanks.
The kit can be delivered on a single pallet for easy inventory, delivery, and on-site convenience.
Auxiliary electric heating elements integrated into the indoor unit. Can be paired with a furnace or boiler using the "dual fuel switch".

Product details

Heating capacity

20.5 MBH (6 kW) for AM2V-020028
34.0 MBH (10 kW) for AM2V-034043
58.0 MBH (17 kW) for AM2V-051078

Cooling capacity range (low - high)

1.4 - 1.5 tons (5.0 - 5.2 kW) for AM2V-020028
2.8 - 3.0 tons (9.8 - 10.5 kW) for AM2V-034043
4.2 - 4.3 tons (14.7 - 15.1 kW) for AM2V-051078

Efficiency ratio (EER)

16.81 for AM2V-020028
16.75 for AM2V-034043
14.46 for AM2V-051078

Coefficient of performance (COP)

4.927 for AM2V-020028
4.909 for AM2V-034043
4.238 for AM2V-051078

Refrigerant type


Minimum outdoor air temperature

-13 °F (-25 °C)

Maximum outdoor air temperature

109 °F (43 °C)

Water flow rates for outdoor unit

3.7 - 8.8 GPM (0.85 - 2.0 m³/h) for AM2V-020028
6.2 - 15.0 GPM (1.4 - 3.4 m³/h) for AM2V-034043
11.4 - 25.5 GPM (2.6 - 5.8 m³/h) for AM2V-051078

Power supply for outdoor unit

208/230 VAC
1 Phase  
60 Hertz  

Total electrical load for outdoor unit

13.0 Amps for AM2V-020028
21.8 Amps for AM2V-034043
35.1 Amps for AM2V-051078

Dimensions of outdoor unit

31¼ inches (795 mm) for AM2V-020028
36½ inches (928 mm) for AM2V-034043
52⅜ inches (1329 mm) for AM2V-051078

46 inches (1165 mm) for AM2V-020028
50¾ inches (1285 mm) for AM2V-034043
49¼ inches (1250 mm) for AM2V-051078

15¾ inches (400 mm) for AM2V-020028
18⅛ inches (460 mm) for AM2V-034043
19½ inches (495 mm) for AM2V-051078

198 lbs (90 kg) for AM2V-020028
291 lbs (132 kg) for AM2V-034043
353 lbs (160 kg) for AM2V-051078

Power supply for indoor unit

230 VAC
1 Phase  
60 Hertz  

Amperage (FLA) for indoor unit

31 Amps for AM2V-020028 & AM2V-034043
43 Amps for AM2V-051078

Electric heater output for indoor unit

20,500 BTU (6 kW) for AM2V-020028 & AM2V-034043
30,700 BTU (9 kW) for AM2V-051078

Maximum operating temperature

165 °F (74 °C)

Maximum operating pressure

30 PSI (2 bar)

Dimensions of indoor unit

28½ inches (723 mm)

16¼ inches (416 mm)

12¾ inches (323 mm)

64 lbs (29 kg)

Hydronic connections

Indoor unit    
1¼ inch NPT (male threads)

Outdoor unit  
1 inch NPT (male threads)

Buffer tank capacity

20 USG (75 L)

Buffer tank water temperature range

45 to 230 °F (7 to 110 °C)

Buffer tank dimensions

26½ inches (668 mm)

21 inches (533 mm)

110 lbs (50 kg)


Limited 5-year warranty for the compressor, 3-year warranty for individual components of the indoor unit and outdoor unit, and a 1-year warranty for the fittings. See warranty sheet for details.

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