Vaillant Heat Pumps In Brief:
Vaillant are a well-known European heating brand. Many UK customers use Vaillant boilers but they have branched-out to be a major supplier of heat pumps. They have a significant slice of the British market and are a reliable company so certainly can be on the list for potential heat pump customers looking to have an upgraded heating system installed.
Although heat pumps can obtain their energy from air, ground or water, most household heating appliance suppliers concentrate on air-source heat pumps which are a practical way to heat homes with hot water. Vaillant is one of the few residential heat pump suppliers which has a range of different heating systems so the customer can choose the setup that is best for their home.
The products are especially quiet, which is important for users: most have been awarded the ‘Quiet Mark’ for their low-decibel sound performance. Some of their most critical parts have been made to resist corrosion, which is important in the rainy British climate.
The brand has four different model ranges. The first is the flexoTHERM air source heat pump, which is the most conventional offering for residential use.
Next there is the aroTHERM hybrid heat pump system, which combines an air-to-water heat pump with a conventional boiler: it always uses the cheapest source of energy, but with the reliability of a standard boiler as an alternate, and backup, form of heating.
The flexoTHERM water-source heat pump range is useful for homeowners who have a nearby source of water such as a lake, river or stream. This can be recommended for rural sites which can utilise this stable input of dependable energy.
The flexoTHERM multi-source heat pump is outstanding in that it can utilise air, water or ground-source for its energy input.
Vaillant did offer a range of ground-source heat pumps for home use, but these have been discontinued. Ground-source heat pumps are efficient, but the heating element needs to be dug into the ground, which limits the locations that it can be installed in and increases costs.
Vaillant heat pumps are certified by the Microgeneration Certification Scheme (MCS), a national quality assurance scheme that ensures high quality standards in renewable energy technologies. It also means that homeowners can access various grants and rebates, depending on which part of the UK you are located in, to reduce purchase and installation costs.
Warranties range from five to seven years duration.
Vaillant Company Overview:
Founded in Germany in 1874, the group of companies now spans Europe with manufacturing sites globally. Unusually for a modern technology company, it remains family-owned. Worldwide it has over 17,000 employees on 10 sites, bringing in €3.7 billion in revenue each year, making it the second-largest heating technology manufacturer in Europe.
Vaillant Heat Pump Specifications
The aroTHERM plus air-to-water heat pump range
- Five different models from 3.5kW to 12kW.
- Environmentally friendly and future-proof.
- Future-proof thanks to the most cutting-edge heat pump technology with natural refrigerant, reducing your carbon footprint.
- High energy efficiency class.
- Very quiet operation – can even be used in densely built-up terraced housing estates.

aroTHERM plus air-to-water 12kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 58 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM plus air-to-water 10kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 58 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM plus air-to-water 7kW
Dimensions (W x H x D mm) | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 53 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM plus air-to-water 5kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 51 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM plus air-to-water 3.5kW
Dimensions (W x H x D mm) | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 51 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
The aroTHERM split air source heat pump range
Enhances the freely available heat from the outside air to heat the home, which can help to reduce resident’s fuel bills and carbon footprint. It comes in two modules: an indoor wall-mounted unit and an outdoor unit.
Up to seven years parts and labour warranties, when installed by a Vaillant partner.
Available in five different sizes of heat output.
aroTHERM Split 12kW
Dimensions outdoor unit (H x W x D mm) | 1480 x 1100 x 450 |
Dimensions indoor unit (H x W x D mm) | 770 x 440 x 350 |
ErP at 35°C | A++ |
ErP at 55°C | A++ |
Sound power level dB(A) | 56 |
Maximum hot water flow temperature °C | 62 |
Global warming potential according to Regulation (EU) No. 517/2014 | 2,088 |
aroTHERM Split 10kW
Dimensions outdoor unit (H x W x D mm) | 1480 x 1100 x 450 |
Dimensions indoor unit (H x W x D mm) | 770 x 440 x 350 |
ErP at 35°C | A++ |
ErP at 55°C | A++ |
Sound power level dB(A) | 56 |
Maximum hot water flow temperature °C | 62 |
Global warming potential according to Regulation (EU) No. 517/2014 | 2,088 |
aroTHERM Split 7kW
Dimensions outdoor unit (H x W x D mm) | 965 x 1100 x 450 |
Dimensions indoor unit (H x W x D mm) | 770 x 440 x 350 |
ErP at 35°C | A++ |
ErP at 55°C | A++ |
Sound power level dB(A) | 55 |
Maximum hot water flow temperature °C | 62 |
Global warming potential according to Regulation (EU) No. 517/2014 | 2,088 |
aroTHERM Split 5kW
Dimensions outdoor unit (H x W x D mm) | 765 x 1100 x 450 |
Dimensions indoor unit (H x W x D mm) | 770 x 440 x 350 |
ErP at 35°C | A++ |
ErP at 55°C | A++ |
Sound power level dB(A) | 54 |
Maximum hot water flow temperature °C | 62 |
Global warming potential according to Regulation (EU) No. 517/2014 | 2,088 |
aroTHERM Split 3.5kW
Dimensions outdoor unit (H x W x D mm) | 765 x 1100 x 450 |
Dimensions indoor unit (H x W x D mm) | 770 x 440 x 350 |
ErP at 35°C | A++ |
ErP at 55°C | A++ |
Sound power level dB(A) | 53 |
Maximum hot water flow temperature °C | 62 |
Global warming potential according to Regulation (EU) No. 517/2014 | 2,088 |
The aroTHERM air-to-water heat pump range
The pump harnesses natural resources, so it can help to save money on home fuel bills and reduce its carbon footprint. Homeowners can benefit from a range of warranties of up to 7 years parts and labour when installed by a renewable partner. There are four sizes of heat output available, so it’s a good solution for most kinds of property.
The aroTHERM range 15kW
Dimensions (H x W x D mm) | 1375 x 1103 x 463 |
ErP at 35°C | A++ |
ErP at 55°C | A+ |
Sound power level dB(A) | 66 |
Maximum hot water flow temperature °C | 63 |
The aroTHERM range 11kW
Dimensions (H x W x D mm) | 975 x 1103 x 463 |
ErP at 35°C | A+ |
ErP at 55°C | A+ |
Sound power level dB(A) | 66 |
Maximum hot water flow temperature °C | 63 |
The aroTHERM range 8kW
Dimensions (H x W x D mm) | 975 x 1103 x 463 |
ErP at 35°C | A++ |
ErP at 55°C | A++ |
Sound power level dB(A) | 60 |
Maximum hot water flow temperature °C | 63 |
The aroTHERM range 5kW
Dimensions (H x W x D mm) | 834 x 970 x 408 |
ErP at 35°C | A++ |
ErP at 55°C | A+ |
Sound power level dB(A) | 58 |
Maximum hot water flow temperature °C | 60 |
The aroTHERM Plus hybrid heat pump system
Hybrid heating solution which combines aroTHERM air-to-water heat pump with a traditional boiler. Unique triVAI technology to ensure the most efficient energy source is always used. Great first step into a renewable and sustainable heating system for your home.
aroTHERM Plus hybrid 12kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 58 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM Plus hybrid 10kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 58 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM Plus hybrid 7kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 53 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM Plus hybrid 5kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 51 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
aroTHERM Plus hybrid 3.5kW
Dimensions (W x H x D) mm | 1,100 x 765 x 449 |
Sound power, EN 12102, EN 14511 LWA, A7/W35 dB(A) | 51 |
Energy efficiency class 35°C band | A+++ |
Energy efficiency class 55°C band | A++ |
Global warming potential | 3 |
flexoTHERM air source heat pump
The heat pump harnesses natural energy from the air, which means it can help to save money on fuel bills and reduce the home’s carbon footprint. Homeowners can benefit from a range of warranties of up to 7 years parts and labour when installed by a Vaillant renewable partner.
There are a range of heat outputs available, so it’s a good solution for homes that have a 400V power supply.
flexoTHERM 5kW 400V
Product dimensions (H x D x W) mm | 1185 x 600 x 595 |
aroCOLLECT dimensions (H x D x W) mm | 1256 x 785 x 1192 |
Weight, with packaging kg | 155 |
Weight, without packaging kg | 145 |
Sound power level A7/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 40.3 |
Energy-related Products at 35°C* band | A+++ |
Energy-related Products at 55°C* band | A+++ |
flexoTHERM 8kW 400V
Product dimensions (H x D x W) mm | 1185 x 600 x 595 |
aroCOLLECT dimensions (H x D x W) mm | 1256 x 785 x 1192 |
Weight, with packaging kg | 170 |
Weight, without packaging kg | 160 |
Sound power level A7/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 45.8 |
Energy-related Products at 35°C* band | A+++ |
Energy-related Products at 55°C* band | A+++ |
flexoTHERM 11kW 400V
Product dimensions (H x D x W) mm | 1185 x 600 x 595 |
aroCOLLECT dimensions (H x D x W) mm | 1256 x 785 x 1192 |
Weight, with packaging kg | 178 |
Weight, without packaging kg | 168 |
Sound power level A7/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 44.4 |
Energy-related Products at 35°C* band | A+++ |
Energy-related Products at 55°C* band | A+++ |
flexoTHERM 15kW 400V
Product dimensions (H x D x W) mm | 1185 x 600 x 595 |
aroCOLLECT dimensions (H x D x W) mm | 1256 x 785 x 1192 |
Weight, with packaging kg | 185 |
Weight, without packaging kg | 176 |
Sound power level A7/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 48.7 |
Energy-related Products at 35°C* band | A+++ |
Energy-related Products at 55°C* band | A+++ |
flexoTHERM 19kW 400V
Product dimensions (H x D x W) mm | 1185 x 600 x 595 |
aroCOLLECT dimensions (H x D x W) mm | 1256 x 785 x 1192 |
Weight, with packaging kg | 197 |
Weight, without packaging kg | 187 |
Sound power level A7/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 48.1 |
Energy-related Products at 35°C* band | A+++ |
Energy-related Products at 55°C* band | A+++ |
flexoTHERM water source heat pump
The heat pump harnesses natural energy from a water source, which can help to save money on home fuel bills and reduce the building’s carbon footprint. Homeowners can benefit from a range of warranties of up to 7 years parts and labour when installed by a Vaillant renewable partner. There are a range of heat outputs available, so it’s a good solution for homes that have a local water source, such as a lake, river or stream.
flexoTHERM water 5kW 230V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 43.3 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 8kW 230V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 46.9 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 11kW 230V
Dimensions (H x W x D) mm | 183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 50.0 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 5kW 400V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 41.2 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 8kW 400V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 47.9 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 11kW 400V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 45.0 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 15kW 400V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 49.9 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
flexoTHERM water 19kW 400V
Dimensions (H x W x D) mm | 1183 x 595 x 600 |
fluoCOLLECT dimensions (H x D x W) mm | 720 x 291 x 733 |
Sound power level B0/W35 EN 12102/EN 14511 LWI in heating mode dB(A) | 50.6 |
Energy-related Products at 35˚C* band | A+++ |
Energy-related Products at 55˚C* band | A+++ |
The flexoTHERM multi-source heat pump
A smart and flexible multi-source heating system that uses renewable heat sources from the ground, water or air. The heat pump can be configured to work with either air, ground, or water sources.
The heat pump comes in different sizes of heat output to suit every property, with 5, 8, 11, 15 and 19kW models available. It’s simple to install, and features intelligent weather compensating controls and Wi-Fi connectivity for remote operation.
flexoTHERM multi-source 5kW 230V
Product dimensions (H x D x W) mm | 1183 x 595 x 600 |
Sound power level B0/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 43.8 |
Energy-related Product 35°C* band | A+++ |
Energy-related Product 55°C* band | A+++ |
flexoTHERM multi-source 8kW 400V
Product dimensions (H x D x W) mm | 1183 x 595 x 600 |
Sound power level B0/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 42.4 |
Energy-related Product 35°C* band | A+++ |
Energy-related Product 55°C* band | A+++ |
flexoTHERM multi-source 11kW 400V
Product dimensions (H x D x W) mm | 1183 x 595 x 600 |
Sound power level B0/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 45.2 |
Energy-related Product 35°C* band | A+++ |
Energy-related Product 55°C* band | A+++ |
flexoTHERM multi-source 15kW 400V
Product dimensions (H x D x W) mm | 1183 x 595 x 600 |
Sound power level B0/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 45.2 |
Energy-related Product 35°C* band | A+++ |
Energy-related Product 55°C* band | A+++ |
*A+++ is achievable when paired with Vaillant’s VRC 700/ VRC 700f system control.
flexoTHERM multi-source 19kW 400V
Product dimensions (H x D x W) mm | 1183 x 595 x 600 |
Sound power level B0/W35 | |
EN 12102/EN 14511 LWI in heating mode dB(A) | 48.4 |
Energy-related Product 35°C* band | A+++ |
Energy-related Product 55°C* band | A+++ |
Vaillant Heat Pump Pros and Cons
Pros
- Good range of products
- Reliable
- More flexible than competitor offerings
- ‘Quiet Mark’ accreditation
- Adapted to British climate
Cons
- Can involve complex installation
- Higher costs than some systems
Vaillant Heat Pump FAQs
Q: How does a heat pump work?
A: By using ambient energy embedded in the surroundings, heat pumps can extract this pollution-free source of energy and then use it to heat water (for example) and pipe it around your home. It does consume some energy to do this, but generally is 75% more efficient than other forms of heating, potentially saving a lot on bills.
Q: Can you attach a heat pump to existing radiators?
A: Heat pumps can often be attached to existing radiators, so it is possible they can be retrofitted into an existing home-heating system without much disruption. Much will depend on the size of the existing radiators as heat pumps operate at lower flow temperatures than traditional gas boilers, so require large or ‘oversized’ radiators to function effectively.
Q: How long do heat pumps last?
A: Modern units currently last for 20-25 years before they need replacing. They have few parts that can wear out, compared to boilers, so are considered more reliable: boiler life expectancy tends to be 10-12 years.
Q: Is there funding available to reduce the cost of the system?
A: Currently there are grants available for heat pump installation but they depend on where you are in the UK. Government funding is prone to abrupt changes of policy so please contact your supplier to discuss what is available now.
Vaillant Heat Pump Summary
Vaillant heat pumps are among the most flexible types available to residential customers. They have a track record of reliability. This makes them a good product to install in a home heating system. There are downsides, depending on the exact model and purpose: ground and water-source heat pumps do have more extensive and complex installations than air-source heat pumps so that is reflected in their costs, although these types do also have advantages to balance that out.
Vaillant is a market-leading company, and can be recommended as a potential home heating system for most situations.