comparison

By Sarah Cooper, Technical Reviewer, MCS Certified Heat Pump Engineer — Last reviewed

Vaillant Arotherm Plus Review: Is It Worth the Price?

First published

TL;DR

  • The Vaillant aroTHERM Plus is one of the UK’s most efficient air source heat pumps, with a SCOP of up to 5.03 and 75°C flow temperatures, making it ideal for older homes with existing radiators.
  • Its R290 refrigerant (GWP 3) ensures compliance with upcoming EU F-Gas regulations, unlike competitors using R32 (GWP 675), which will be phased out by 2030.
  • Installed costs range from £9,000-£20,000, but the £7,500 Boiler Upgrade Scheme (BUS) grant can reduce this to £1,500-£12,500, making it more accessible.
  • Real-world running costs are 30-50% cheaper than gas boilers in well-insulated homes, but efficiency drops significantly in poorly insulated properties, increasing costs.
  • The sensoCOMFORT controller offers intuitive weather compensation and scheduling, but the myVAILLANT app has mixed reviews due to Wi-Fi connectivity issues and limited smart home integration.
  • Best suited for homeowners prioritising long-term efficiency, low carbon footprint, and retrofit compatibility, but not the cheapest upfront option.
  • Pairing with solar PV and battery storage can further reduce running costs and enhance sustainability.

In 2024, UK homeowners installed over 50,000 heat pumps, marking a significant shift toward low-carbon heating solutions, according to industry reports from MCS. With over 100 models available, selecting the right heat pump can be daunting. The Vaillant aroTHERM Plus consistently ranks at the top of "best heat pump" lists, praised for its high efficiency, low-carbon refrigerant, and ability to deliver 75°C flow temperatures. However, with installed costs £2,000-£5,000 higher than budget alternatives, is it worth the premium?

This independent review provides a comprehensive analysis of the Vaillant aroTHERM Plus, covering:

  • Real UK running costs and how they compare to gas boilers.
  • Grant savings through the Boiler Upgrade Scheme (BUS) and how to maximise them.
  • Hands-on testing of the myVAILLANT app and sensoCOMFORT controller.
  • A detailed head-to-head comparison with competitors like the Mitsubishi Ecodan and Daikin Altherma.
  • Common problems, installer tips, and whether the aroTHERM Plus is truly "future-proof" or overhyped.

We’ll also explore real-world case studies, regulatory impacts, and practical advice for homeowners considering this investment.

Table of Contents

Vaillant aroTHERM Plus: Our Independent A-E Rating

We evaluated the Vaillant aroTHERM Plus across five critical categories, scoring it from A (excellent) to E (poor). Here’s how it performed:

CategoryRatingWhy?
EfficiencyAThe aroTHERM Plus achieves a SCOP of up to 5.03 (7kW model) and can deliver 75°C flow temperatures, making it one of the most efficient air source heat pumps (ASHPs) for UK climates. It outperforms gas boilers in well-insulated homes, where it can achieve 30-50% lower running costs.
Retrofit-ReadinessAThe R290 refrigerant (GWP 3) and high flow temperatures make it ideal for older homes with existing radiators. Its Quiet Mark certification (54dB) also makes it suitable for urban installations, where noise restrictions may apply.
Running CostsBIn optimal conditions, the aroTHERM Plus is 30-50% cheaper to run than a gas boiler. However, efficiency drops significantly in poorly insulated homes, where the SCOP can fall below 3.0, increasing running costs. Electricity prices (currently 24.5p/kWh, according to OFGEM) also impact savings.
User-FriendlinessCThe sensoCOMFORT controller is intuitive and offers features like weather compensation and holiday mode. However, the myVAILLANT app has received mixed reviews for Wi-Fi connectivity issues and limited third-party smart home integration, such as Google Home or Apple HomeKit.
PriceDThe installed cost ranges from £9,000-£20,000 (before grants). While the £7,500 Boiler Upgrade Scheme (BUS) grant can reduce this significantly, the aroTHERM Plus remains £2,000-£5,000 more expensive than budget alternatives like the Samsung EHS Mono.

Verdict: The Vaillant aroTHERM Plus earns top marks for efficiency and retrofit readiness, but its high upfront cost and app quirks hold it back. It is best suited for homeowners who prioritise long-term savings, low carbon footprint, and compatibility with older homes over initial affordability.

For those considering alternatives, our heat pump comparison guide provides a detailed breakdown of other top models.

Is the aroTHERM Plus Worth the Premium Price in 2026?

The Vaillant aroTHERM Plus is not a budget option. A 5kW model starts at £9,000 installed, while a 12kW unit can exceed £20,000-before grants. For comparison:

  • A Mitsubishi Ecodan 8.5kW costs around £12,000 installed.
  • A Samsung EHS Mono 9kW starts at £10,000 installed.
  • A Daikin Altherma 3 8kW ranges from £13,000-£16,000 installed.

Despite the higher upfront cost, three key factors justify the premium:

1. Future-Proofing with R290 Refrigerant

The Vaillant aroTHERM Plus uses R290 (propane), a natural refrigerant with a Global Warming Potential (GWP) of 3. This is a stark contrast to R32, which has a GWP of 675 and is used in most competing heat pumps. The choice of R290 is significant for several reasons:

  • Regulatory Compliance: The EU F-Gas Regulation is phasing out high-GWP refrigerants, with a ban on R32 and similar refrigerants expected by 2030. This means that heat pumps using R32 may become obsolete or require costly retrofits in the near future. The aroTHERM Plus, with its R290 refrigerant, is exempt from these regulations, ensuring long-term compliance.
  • Efficiency at Low Temperatures: R290 is more efficient at low temperatures compared to R32, which improves performance during UK winters. This is particularly important for homes in colder regions, where heat pumps must work harder to maintain indoor comfort.
  • Environmental Impact: With a GWP of 3, R290 has a minimal environmental impact, aligning with the UK’s net-zero carbon targets. This makes the aroTHERM Plus a more sustainable choice for eco-conscious homeowners.

Downside: R290 is mildly flammable, which requires installers to follow strict safety protocols. For example, indoor units must be installed in well-ventilated areas, and installers must be MCS-certified to handle R290 safely. However, when installed correctly, the risk is minimal and manageable.

For more information on refrigerants and their environmental impact, see the GOV.UK F-Gas Regulation guidance.

2. High Flow Temperatures (75°C): Retrofit-Friendly

One of the biggest challenges with heat pumps is their compatibility with older heating systems, which often require higher flow temperatures (60-70°C) to function effectively. Most heat pumps max out at 60-65°C, which means homeowners with older radiators may need to upgrade their entire heating system, adding £1,000-£3,000 to the overall cost.

The Vaillant aroTHERM Plus addresses this issue by delivering 75°C flow temperatures, making it one of the few ASHPs suitable for retrofits without radiator upgrades. This feature is particularly valuable for:

  • Older homes (pre-1980s) with existing radiators.
  • Homes with high heat demand, such as those in colder regions or with poor insulation.
  • Homeowners looking to avoid costly upgrades to their heating systems.

Trade-off: While 75°C flow temperatures improve compatibility with older systems, they reduce efficiency. For optimal performance, aim for 55-60°C flow temperatures and prioritise insulation upgrades to maximise savings. Our home insulation guide provides practical tips for improving your home’s energy efficiency.

3. Quiet Mark Certification: Ideal for Urban Installations

Noise levels are a critical consideration for heat pump installations, particularly in urban areas where noise restrictions may apply. The Vaillant aroTHERM Plus is Quiet Mark certified, operating at just 54dB(A) at 1 metre-comparable to the noise level of a modern fridge. This makes it one of the quietest ASHPs on the market, ideal for:

  • Urban installations where noise complaints could delay or derail a project.
  • Homes with outdoor units near bedrooms or living spaces.
  • Homeowners who prioritise a quiet living environment.

For reference, here’s how the aroTHERM Plus compares to other common noise levels:

  • 50dB: Quiet conversation.
  • 54dB: Vaillant aroTHERM Plus (at 1m).
  • 55dB: Modern fridge.
  • 60dB: Normal conversation.
  • 70dB: Vacuum cleaner.

For more details on noise levels and Quiet Mark certification, visit the Quiet Mark website.

Case Study: The Smiths, Manchester - A Real-World Example

To illustrate the real-world performance of the Vaillant aroTHERM Plus, let’s look at a composite case study based on typical UK installations:

Home Details:

  • Type: 1930s semi-detached house, 3 bedrooms.
  • EPC Rating: D (poor insulation, single-glazed windows).
  • Old System: 20-year-old gas boiler with 85% efficiency.
  • New System: Vaillant aroTHERM Plus 7kW with new radiators (total cost: £15,000).

Grant and Savings:

  • Boiler Upgrade Scheme (BUS) Grant: £7,500, reducing the net cost to £7,500.
  • Annual Savings: £650 vs. gas boiler, based on Energy Saving Trust estimates.
  • Payback Period: 11.5 years, assuming no further increases in energy prices.
  • Carbon Emissions: Reduced by 50%, from 2,900 kg CO₂/year to 1,450 kg CO₂/year.

Key Takeaways:

  • The BUS grant significantly reduces the upfront cost, making the aroTHERM Plus more accessible.
  • Annual savings of £650 are achievable in a moderately insulated home, but better insulation could increase savings further.
  • The payback period is longer than some alternatives, but the carbon savings and future-proofing make it a worthwhile investment for homeowners prioritising sustainability.

For a personalised estimate of your potential savings, use our heat pump running costs calculator.

Is the aroTHERM Plus Worth It?

  • Yes, if:
    • You want a long-term, low-carbon heating solution.
    • Your home is moderately to well-insulated, or you plan to upgrade insulation.
    • You can afford the higher upfront cost and benefit from the BUS grant.
    • You live in an urban area where noise restrictions apply.
  • No, if:
    • You are on a tight budget and need the cheapest option.
    • Your home is poorly insulated, and you are unwilling to upgrade.
    • You prioritise short-term savings over long-term efficiency and sustainability.

Real UK Running Costs: aroTHERM Plus vs. Gas Boiler

Heat pumps are cheaper to run than gas boilers, but only if your home is well-insulated. The efficiency of a heat pump is measured by its Seasonal Coefficient of Performance (SCOP), which indicates how much heat is produced per unit of electricity consumed. A higher SCOP means lower running costs.

Here’s how the Vaillant aroTHERM Plus compares to a gas boiler in terms of annual running costs:

Annual Running Costs (2026 Estimates)

SystemEfficiencyAnnual Cost (3-bed house)Savings vs. Gas BoilerCarbon Emissions (kg CO₂/year)
Gas boiler (85% eff.)85%£1,200-2,900
aroTHERM Plus (SCOP 4.5)450%£650£5501,200
aroTHERM Plus (SCOP 3.0)300%£975£2251,800
Mitsubishi Ecodan (SCOP 3.8)380%£760£4401,400

Assumptions:

  • Annual heat demand: 15,000 kWh (typical for a 3-bed house).
  • Gas price: 7.42p/kWh (OFGEM 2024).
  • Electricity price: 24.5p/kWh (OFGEM 2024).
  • SCOP varies by insulation: Well-insulated homes achieve SCOP 4.5, while poorly insulated homes may see SCOP 3.0 or lower.

Key Takeaways on Running Costs

  1. Insulation is Everything:

    • A well-insulated home (SCOP 4.5) can save £550/year compared to a gas boiler.
    • A poorly insulated home (SCOP 3.0) saves only £225/year, making the payback period much longer.
    • Upgrading insulation (e.g., loft, walls, windows) can dramatically improve efficiency and savings. Our home insulation guide provides practical tips.

  2. Electricity Prices Matter:

    • If electricity prices drop to 20p/kWh, savings increase to £650/year for a SCOP 4.5 system.
    • Conversely, if electricity prices rise, savings will decrease. Monitoring OFGEM’s price cap can help you anticipate changes.

  3. Carbon Savings:

    • The aroTHERM Plus reduces carbon emissions by 50-60% compared to a gas boiler, aligning with the UK’s net-zero targets.
    • For homeowners prioritising sustainability, this is a significant advantage.

  4. Regional Variations:

    • Running costs can vary by region due to differences in climate and energy prices. For example, homes in Scotland may have higher heating demands than those in Southern England.
    • Use our heat pump running costs calculator to estimate savings based on your location and home size.

How Insulation Impacts Efficiency

The efficiency of a heat pump is heavily dependent on home insulation. Here’s how different insulation levels impact the SCOP and running costs of the aroTHERM Plus:

Insulation LevelSCOPAnnual Running CostSavings vs. Gas BoilerPayback Period (After Grant)
Poor (EPC F/G)2.5£1,170£3025+ years
Moderate (EPC D/E)3.0£975£22515-20 years
Good (EPC C)3.8£760£44010-15 years
Excellent (EPC A/B)4.5£650£5507-10 years

Recommendations:

  • Prioritise insulation upgrades before installing a heat pump. Focus on:
    • Loft insulation (270mm thickness).
    • Cavity wall insulation (if applicable).
    • Double or triple-glazed windows.
    • Draught-proofing doors and windows.
  • Use the Energy Saving Trust’s insulation advice for tailored recommendations.

Key Features Explained: Why R290 and 75°C Flow Matter

The Vaillant aroTHERM Plus stands out from competitors due to its unique features, which address common challenges in heat pump adoption. Below, we explore the key features in detail and explain why they matter for UK homeowners.

1. R290 Refrigerant: The "Future-Proof" Choice

The R290 refrigerant (propane) is one of the most significant advantages of the aroTHERM Plus. Here’s why it matters:

  • Low Global Warming Potential (GWP):

    • R290 has a GWP of 3, compared to 675 for R32 (used in most competitors).
    • This makes it far more environmentally friendly and compliant with upcoming regulations.

  • Regulatory Compliance:

    • The EU F-Gas Regulation is phasing out high-GWP refrigerants, with a ban on R32 expected by 2030.
    • Heat pumps using R32 may require costly retrofits or replacements in the near future.
    • The aroTHERM Plus, with its R290 refrigerant, is exempt from these regulations, ensuring long-term compliance.

  • Efficiency at Low Temperatures:

    • R290 performs better at low temperatures compared to R32, making it more efficient in UK winters.
    • This is particularly important for homes in colder regions, where heat pumps must work harder to maintain indoor comfort.

  • Safety Considerations:

    • R290 is mildly flammable, which requires installers to follow strict safety protocols.
    • MCS-certified installers are trained to handle R290 safely, minimising risks.
    • Indoor units must be installed in well-ventilated areas to prevent gas accumulation.

For more information on refrigerants and their environmental impact, see the GOV.UK F-Gas Regulation guidance.

2. 75°C Flow Temperatures: Retrofit-Friendly

Most heat pumps struggle with older heating systems, which often require higher flow temperatures (60-70°C) to function effectively. The Vaillant aroTHERM Plus addresses this challenge by delivering 75°C flow temperatures, making it one of the few ASHPs suitable for retrofits without radiator upgrades.

Why This Matters:

  • Compatibility with Older Radiators:

    • Older homes often have radiators designed for high flow temperatures (70-80°C).
    • Most heat pumps max out at 60-65°C, which can lead to cold spots and reduced comfort.
    • The aroTHERM Plus’s 75°C flow temperatures ensure compatibility with existing radiators, eliminating the need for costly upgrades.

  • Cost Savings:

    • Upgrading radiators can add £1,000-£3,000 to the overall cost of a heat pump installation.
    • By avoiding this expense, the aroTHERM Plus can reduce upfront costs and shorten the payback period.

  • Flexibility for High Heat Demand:

    • Homes in colder regions or with poor insulation may require higher flow temperatures to maintain comfort.
    • The aroTHERM Plus’s 75°C capability ensures it can meet these demands without sacrificing performance.

Trade-off:

  • While 75°C flow temperatures improve compatibility, they reduce efficiency.
  • For optimal performance, aim for 55-60°C flow temperatures and prioritise insulation upgrades to maximise savings.

3. Quiet Mark Certification (54dB)

Noise levels are a critical consideration for heat pump installations, particularly in urban areas where noise restrictions may apply. The Vaillant aroTHERM Plus is Quiet Mark certified, operating at just 54dB(A) at 1 metre-comparable to the noise level of a modern fridge.

Why This Matters:

  • Urban Installations:

    • Noise complaints can delay or derail heat pump installations in urban areas.
    • The aroTHERM Plus’s 54dB noise level ensures compliance with most local noise regulations.

  • Comfortable Living Environment:

    • A quiet heat pump is less disruptive to daily life, particularly if the outdoor unit is near bedrooms or living spaces.

  • Comparison to Competitors:

    • Most heat pumps operate at 55-60dB, making the aroTHERM Plus one of the quietest options on the market.

For more details on noise levels and Quiet Mark certification, visit the Quiet Mark website.

4. sensoCOMFORT Controller: Smart but Flawed

The sensoCOMFORT controller is a wall-mounted touchscreen that allows homeowners to control the Vaillant aroTHERM Plus. Here’s what you need to know:

Key Features: ✅ Weather Compensation: Adjusts flow temperatures based on outdoor temperature, improving efficiency. ✅ Holiday Mode: Reduces energy use when you’re away, saving money. ✅ Hot Water Scheduling: Set timers for heating and hot water, ensuring comfort when needed. ✅ Intuitive Interface: The touchscreen is user-friendly and easy to navigate.

Limitations: ❌ No Geofencing: Unlike smart thermostats like Nest or Hive, the sensoCOMFORT cannot detect if you’re home and adjust settings automatically. ❌ Limited Smart Home Integration: Works with Amazon Alexa but not Google Home or Apple HomeKit. ❌ Basic Customisation: Cannot set different temperatures for individual rooms.

Verdict: The sensoCOMFORT controller is intuitive and functional, but it lacks some of the advanced features found in third-party smart thermostats. For homeowners seeking greater customisation, pairing the aroTHERM Plus with a Nest or Hive thermostat may be a better option.

The User Experience: A Hands-On Review of the App & Controls

The user experience of a heat pump is a critical factor in its long-term satisfaction. The Vaillant aroTHERM Plus offers two primary control options: the sensoCOMFORT controller and the myVAILLANT app. Below, we provide a hands-on review of both.

sensoCOMFORT Controller: Intuitive but Basic

The sensoCOMFORT controller is a wall-mounted touchscreen that provides direct control over the aroTHERM Plus. Here’s what we found during testing:

Pros: ✅ Weather Compensation: Automatically adjusts flow temperatures based on outdoor conditions, improving efficiency. ✅ Holiday Mode: Reduces energy use when you’re away, saving money without sacrificing comfort. ✅ Hot Water Scheduling: Allows you to set timers for heating and hot water, ensuring comfort when needed. ✅ User-Friendly Interface: The touchscreen is intuitive and responsive, making it easy to navigate.

Cons: ❌ No Geofencing: Unlike smart thermostats like Nest or Hive, the sensoCOMFORT cannot detect if you’re home and adjust settings automatically. ❌ Limited Smart Home Integration: Works with Amazon Alexa but not Google Home or Apple HomeKit. ❌ Basic Customisation: Cannot set different temperatures for individual rooms, which may be a drawback for larger homes.

Verdict: The sensoCOMFORT controller is a solid, user-friendly option for controlling the aroTHERM Plus. However, it lacks some of the advanced features found in third-party smart thermostats. For homeowners seeking greater customisation, pairing the aroTHERM Plus with a Nest or Hive thermostat may be a better choice.

myVAILLANT App: Mixed Reviews

The myVAILLANT app allows homeowners to control the aroTHERM Plus remotely via their smartphone. Here’s what users are saying:

Pros: ✅ Real-Time Energy Monitoring: Track your energy usage and savings in real time. ✅ Fault Alerts: Receive notifications if the system encounters an issue, allowing for quick troubleshooting. ✅ Remote Control: Adjust temperature settings, schedules, and modes from anywhere. ✅ Alexa Integration: Works with Amazon Alexa for voice control.

Cons: ❌ Wi-Fi Connectivity Issues: Some users report frequent dropouts, requiring manual reconnection. ❌ Limited Customisation: Cannot set different temperatures for individual rooms, which may be a drawback for larger homes. ❌ No Google Home/Apple HomeKit Support: Lacks integration with Google Home or Apple HomeKit, limiting smart home compatibility. ❌ App Reliability: Some users report crashes or slow response times, particularly during peak usage.

Verdict: The myVAILLANT app is functional but not best-in-class. While it offers remote control and energy monitoring, its reliability issues and limited smart home integration hold it back. For homeowners prioritising smart home compatibility, pairing the aroTHERM Plus with a third-party thermostat (e.g., Nest) may be a better option.

How to Get the aroTHERM Plus for £1,500: A Guide to the BUS Grant

The Boiler Upgrade Scheme (BUS) offers £7,500 off the cost of a heat pump, making the Vaillant aroTHERM Plus far more accessible. Here’s a step-by-step guide to maximising your savings:

Step 1: Check Eligibility

To qualify for the BUS grant, you must meet the following criteria:

  • Property Location: Must be in England or Wales (Scotland has separate grants).
  • Replacement: Must replace a gas/oil boiler or electric heating (not an existing heat pump).
  • EPC Requirements: Your home must have no uninsulated cavity walls or loft (unless exempt). If your home has an EPC rating of F or G, you may need to upgrade insulation before applying.
  • Installer: Must use an MCS-certified installer.

For full eligibility details, visit the GOV.UK BUS guidance.

Step 2: Get Quotes from MCS Installers

  • Use the MCS installer database to find Vaillant-approved installers in your area.
  • Get 3+ quotes: Prices can vary by £2,000-£5,000 for the same job, so it’s essential to compare options.
  • Ask for:
    • An itemised breakdown of costs (unit, labour, radiators, etc.).
    • Warranty details (standard 2 years, extendable to 7 with Vaillant MasterTEC).
    • References from past customers.

For help finding an installer, use our MCS installer tool.

Step 3: Apply for the Grant

  • Your installer applies on your behalf-you do not need to submit a separate application.
  • Processing time: Typically 4-8 weeks.
  • Payment: The £7,500 grant is deducted directly from your invoice, reducing your upfront cost.

Example Cost Breakdown

Here’s how the BUS grant can reduce the cost of the aroTHERM Plus:

ModelInstalled CostAfter BUS GrantAdditional Savings
aroTHERM Plus 5kW£9,000£1,500£300/year vs. gas (SCOP 4.5)
aroTHERM Plus 7kW£12,000£4,500£500/year vs. gas (SCOP 4.5)
aroTHERM Plus 12kW£20,000£12,500£800/year vs. gas (SCOP 4.5)

Key Takeaways:

  • The BUS grant can reduce the cost of a 5kW model to just £1,500, making it one of the most affordable heat pumps on the market.
  • Larger models (7kW-12kW) still require a significant upfront investment, but the annual savings can offset this over time.
  • Insulation upgrades can further increase savings and shorten the payback period.

For more details on the BUS grant, see our £7,500 grant guide.

aroTHERM Plus vs. Competitors: A Head-to-Head Comparison

The Vaillant aroTHERM Plus is one of the top-performing heat pumps on the market, but how does it compare to its main competitors? Below, we provide a detailed head-to-head comparison with the Mitsubishi Ecodan, Daikin Altherma 3, and Samsung EHS Mono.

Feature Comparison Table

FeatureVaillant aroTHERM PlusMitsubishi EcodanDaikin Altherma 3Samsung EHS Mono
RefrigerantR290 (GWP 3)R32 (GWP 675)R32 (GWP 675)R32 (GWP 675)
Max Flow Temp75°C60°C65°C65°C
Min Operating Temp-20°C-15°C-20°C-25°C
SCOP (7kW model)5.034.24.54.3
Noise Level54dB (Quiet Mark)58dB56dB55dB
Warranty2-7 years5-7 years3-7 years5 years
Installed Cost (7kW)£12,000-£15,000£11,000-£14,000£13,000-£16,000£10,000-£13,000
After BUS Grant£4,500-£7,500£3,500-£6,500£5,500-£8,500£2,500-£5,500

Which Model is Best for You?

  • Best for Retrofits: Vaillant aroTHERM Plus (75°C flow temps).
  • Best for Efficiency: Vaillant aroTHERM Plus (SCOP 5.03).
  • Best Budget Option: Samsung EHS Mono (£10,000 installed).
  • Best for Cold Climates: Daikin Altherma 3 (-20°C min temp).
  • Best for Noise-Sensitive Areas: Vaillant aroTHERM Plus (54dB, Quiet Mark certified).

Winner?

  • If you prioritise efficiency, retrofit compatibility, and future-proofing, the Vaillant aroTHERM Plus is the best choice.
  • If you’re on a tight budget, the Samsung EHS Mono offers good performance at a lower cost.
  • If you live in a cold climate, the Daikin Altherma 3 is a strong contender.

For a more detailed comparison, see our heat pump comparison guide.

Common Problems & Criticisms: The "Bad and the Ugly"

While the Vaillant aroTHERM Plus is a high-performing heat pump, it is not without its drawbacks. Below, we explore the most common problems and criticisms reported by users and installers.

1. High Upfront Cost

  • The installed cost of the aroTHERM Plus ranges from £9,000-£20,000 (before grants), which is £2,000-£5,000 more expensive than budget alternatives like the Samsung EHS Mono.
  • Workaround: Use the £7,500 BUS grant to reduce the upfront cost. Additionally, compare quotes from multiple installers to ensure you’re getting the best price.

2. App Reliability Issues

  • The myVAILLANT app has received mixed reviews for Wi-Fi connectivity issues and limited smart home integration.
  • Workaround: Pair the aroTHERM Plus with a third-party smart thermostat (e.g., Nest or Hive) for better reliability and customisation.

3. Flammable Refrigerant (R290)

  • R290 is mildly flammable, which requires installers to follow strict safety protocols.
  • Workaround: Ensure your installer is MCS-certified and follows Vaillant’s guidelines for safe installation. Indoor units should be installed in well-ventilated areas.

4. Efficiency Drops in Poorly Insulated Homes

  • The SCOP of the aroTHERM Plus can fall below 3.0 in poorly insulated homes, increasing running costs.
  • Workaround: Upgrade insulation before installing the heat pump. Focus on loft, walls, and windows to maximise efficiency. Our home insulation guide provides practical tips.

Finding the Right Installer: Get Your Vaillant Quotes

Choosing the right installer is critical to the success of your heat pump installation. Below, we outline the steps to finding a reputable installer and getting the best price for your Vaillant aroTHERM Plus.

Step 1: Use the MCS Database

  • Visit the MCS installer database and filter for Vaillant-approved installers in your area.
  • MCS certification ensures that the installer meets strict quality and safety standards.
  • Look for installers with positive reviews and a track record of successful installations.

Step 2: Get 3+ Quotes

  • Prices can vary by £2,000-£5,000 for the same job, so it’s essential to compare multiple quotes.
  • Ask for:
    • An itemised breakdown of costs (unit, labour, radiators, etc.).
    • Warranty details (standard 2 years, extendable to 7 with Vaillant MasterTEC).
    • References from past customers.
    • Examples of previous work, including photos or case studies.

Step 3: Check Reviews

  • Look for Google or MyBuilder reviews mentioning:
    • Noise levels: The aroTHERM Plus should operate at <55dB in most installations.
    • App functionality: Ask about Wi-Fi reliability and smart home integration.
    • After-sales support: Vaillant’s helpline is 0330 100 3000, but local installers should also provide ongoing support.

For help finding an installer, use our MCS installer tool.

Additional Considerations for Homeowners

Before investing in a Vaillant aroTHERM Plus, there are several additional factors to consider to ensure it’s the right choice for your home.

1. Pairing with Solar PV and Battery Storage

  • The aroTHERM Plus can integrate with solar PV panels to reduce running costs and enhance sustainability.
  • In summer, solar panels can power the heat pump directly, cutting electricity bills.
  • For best results, pair the aroTHERM Plus with a battery storage system (e.g., Tesla Powerwall) to store excess solar energy for use during peak demand.

For more information on solar PV and battery storage, see our solar PV guide.

2. Smart Home Integration

  • The myVAILLANT app offers basic smart home integration, including Amazon Alexa support.
  • However, it lacks compatibility with Google Home and Apple HomeKit.
  • For greater customisation, consider pairing the aroTHERM Plus with a third-party smart thermostat (e.g., Nest or Hive).

3. Maintenance and Servicing

  • Heat pumps require annual servicing to maintain efficiency and longevity.
  • Servicing costs typically range from £100-£200/year.
  • Vaillant offers a 2-year standard warranty, extendable to 7 years if installed by a Vaillant MasterTEC partner.

For more information on heat pump maintenance, see our heat pump maintenance guide.

4. Environmental Impact and Carbon Savings

  • The aroTHERM Plus reduces carbon emissions by 50-60% compared to a gas boiler.
  • This aligns with the UK’s net-zero carbon targets and makes it a sustainable choice for eco-conscious homeowners.
  • Pairing the aroTHERM Plus with renewable energy sources (e.g., solar PV) can further reduce your carbon footprint.

For more information on the environmental impact of heat pumps, see the Energy Saving Trust’s heat pump advice.

FAQ

1. How long does a Vaillant aroTHERM Plus last?

Most heat pumps, including the Vaillant aroTHERM Plus, have a lifespan of 15-20 years with proper maintenance. Key factors that influence longevity include:

  • Annual servicing: Regular maintenance (£100-£200/year) ensures optimal performance and extends the lifespan.
  • Installation quality: A poor installation can lead to premature wear and tear, so it’s essential to use an MCS-certified installer.
  • Usage patterns: Running the heat pump at high flow temperatures (75°C) for extended periods can reduce efficiency and lifespan.

Warranty:

  • Standard warranty: 2 years (parts and labour).
  • Extended warranty: Up to 7 years if installed by a Vaillant MasterTEC partner.

For more information on heat pump warranties, see our heat pump warranty guide.

2. Can the aroTHERM Plus work with solar panels?

Yes! The Vaillant aroTHERM Plus can integrate with solar PV panels to reduce running costs and enhance sustainability. Here’s how it works:

  • Direct power: In summer, solar panels can power the heat pump directly, reducing reliance on the grid.
  • Battery storage: Pairing the aroTHERM Plus with a battery storage system (e.g., Tesla Powerwall) allows you to store excess solar energy for use during peak demand.
  • Smart controls: The sensoCOMFORT controller can be programmed to prioritise solar energy when available.

Benefits:

  • Lower running costs: Solar energy is cheaper than grid electricity, reducing annual bills.
  • Reduced carbon footprint: Using renewable energy further lowers your home’s carbon emissions.

For more information on pairing heat pumps with solar PV, see our solar PV and heat pumps guide.

3. Is the aroTHERM Plus noisy?

The Vaillant aroTHERM Plus is Quiet Mark certified, operating at just 54dB(A) at 1 metre-comparable to the noise level of a modern fridge. This makes it one of the quietest ASHPs on the market, ideal for:

  • Urban installations where noise restrictions apply.
  • Homes with outdoor units near bedrooms or living spaces.
  • Homeowners who prioritise a quiet living environment.

Noise Comparison:

  • 50dB: Quiet conversation.
  • 54dB: Vaillant aroTHERM Plus (at 1m).
  • 55dB: Modern fridge.
  • 60dB: Normal conversation.
  • 70dB: Vacuum cleaner.

For more details on noise levels and Quiet Mark certification, visit the Quiet Mark website.

4. What’s the difference between the 5kW, 7kW, and 12kW models?

The Vaillant aroTHERM Plus is available in three sizes: 5kW, 7kW, and 12kW. The right size for your home depends on heat demand, insulation, and property size. Here’s a breakdown:

ModelSuitable forInstalled Cost (After Grant)SCOPAnnual Running Cost (3-bed house)
5kW1-2 bed flats, well-insulated£1,500-£3,5005.03£650
7kW3-bed semi-detached£4,500-£7,5005.03£650
12kW4+ bed detached, poor insulation£12,500-£15,0004.5£760

How to Choose:

  • Use our home suitability check to determine the right size for your property.
  • Consider insulation: Poorly insulated homes may require a larger model (e.g., 12kW) to meet heat demand.
  • Consult an MCS installer: They can perform a heat loss calculation to recommend the best size.

5. How does the aroTHERM Plus compare to a gas boiler?

The Vaillant aroTHERM Plus and gas boilers each have advantages and disadvantages. Here’s a detailed comparison:

FactoraroTHERM PlusGas Boiler
Upfront Cost£9,000-£20,000 (£1,500-£12,500 after grant)£2,500-£4,500
Running Cost (3-bed)£650-£975/year£1,200/year
Carbon Emissions1,200-1,800 kg CO₂/year2,900 kg CO₂/year
Lifespan15-20 years10-15 years
Maintenance£100-£200/year£80-£150/year
CompatibilityRequires good insulationWorks with any home
Future-ProofingR290 refrigerant (GWP 3)Fossil fuel-dependent

Winner?

  • Long-term savings: The aroTHERM Plus is £550/year cheaper to run in well-insulated homes.
  • Upfront cost: Gas boilers are £5,000-£10,000 cheaper to install.
  • Carbon footprint: The aroTHERM Plus reduces emissions by 50-60%.
  • Future-proofing: The aroTHERM Plus is compliant with upcoming regulations, while gas boilers may be phased out in the coming decades.

For a more detailed comparison, see our heat pump vs. gas boiler guide.

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