The Vaillant aroTHERM Plus
The "Boiler Replacement" Heat Pump. 75°C flow temperature, whisper-quiet operation, and designed specifically for UK retrofits.
Why We Install Vaillant
We choose the aroTHERM Plus because it solves the biggest problem with heat pumps: Temperature. Most units only reach 55°C, requiring larger radiators. The Vaillant reaches 75°C, meaning it works with your existing radiators in most cases.
Weather Compensation
Eliminate energy waste.
The sensoCOMFORT system uses an external sensor to monitor ambient weather in real-time. By detecting temperature drops outside before they affect your home, it gently adjusts the flow temperature.
- Proactive: Stops the "Stop/Start" cycling of old boilers.
- Low & Slow: Runs at 35-40°C for maximum efficiency (SCOP 4.0+).
App Control & Support
Complete control via myVAILLANT.
Manage your heating zones and hot water from anywhere in the world. Plus, it connects directly to our engineering team.
- Zone Management: Heat only the rooms you are using.
- Holiday Mode: Set "Frost Protection" while you are away.
- Remote Diagnostics: We can fix many faults without a home visit.
Energy Dashboard
Verify your savings.
The sensoCOMFORT screen features a live Energy Dashboard to validate performance and efficiency.
- Env. Yield: See how much free energy you have harvested.
- Working Figure: Live SCOP calculation (Efficiency).
- Power Usage: Track Heating vs Hot Water costs.
*Real world cost per unit of heat delivered. Based on 24p/kWh electricity.
Comparison: A gas boiler costs approx 7-8p per kWh.
This estimate covers the heat pump system only. It excludes radiator upgrades or pipework changes.
Suitability of existing radiators is determined via a full room-by-room Volumetric Heat Loss Survey. If upgrades are required to achieve maximum efficiency (SCOP) or hydraulic balancing, these will be quoted separately following your technical survey.
| Feature |
Our Pick
Vaillant aroTHERM Plus | Viessmann Vitocal 150-A | Daikin Altherma 3 | Mitsubishi Ecodan R32 |
|---|---|---|---|---|
| Max Flow Temp Radiator Compatibility | 75°C ✓ | 70°C ✓ | 60°C ⚠ | 60°C ⚠ |
| Refrigerant Environmental Impact | Natural R290 | Natural R290 | Synthetic R32 | Synthetic R32 |
| Efficiency (SCOP) @ 42°C "Sweet Spot" | 4.13 (A+++) | 4.05 (A+++) | 3.75 (A++) | 3.72 (A++) |
| Noise Level Sound Pressure @ 3m | 28 dB(A) | 30 dB(A) | 38 dB(A) | 40 dB(A) |
| Warranty Standard Term | 7 Years | 5-7 Years | 3-5 Years | 3-5 Years |
| Dimensions Outdoor Unit Size | Compact | Compact | Large (Tall) | Large (Boxy) |
The Expert Verdict
Why we recommend Vaillant over the competition.
The "Temperature" Problem
Competitor units often use older R32 Refrigerant, limiting their flow temperature to 55°C. This struggles in older homes.
The Vaillant aroTHERM Plus uses R290 to reach 75°C, matching your old gas boiler. This means you rarely need to replace your radiators.
The "Support" Advantage
While Viessmann offers similar performance, we choose Vaillant for peace of mind. Vaillant manufactures here in the UK & Europe.
Spare parts are stocked at almost every local merchant in the Midlands. If you ever need a repair, it can usually be fixed same-day, rather than waiting for parts from Germany.
Vaillant aroTherm Plus Features
No. Because the Vaillant aroTHERM Plus reaches 75°C, it is designed specifically to work with existing radiators. During our survey, we perform a "Volumetric Heat Loss Calculation" to confirm this. In 80% of our retrofits, we only need to upgrade 1 or 2 radiators (usually in the lounge or hallway) to ensure maximum efficiency.
It is whisper quiet. The aroTHERM Plus is Quiet Mark Certified. At a distance of 3 metres, the sound pressure is just 28dB—which is quieter than a library whisper. It also features a "Night Mode" which reduces fan speed during sleeping hours to ensure you and your neighbours are never disturbed.
£7,500. The Boiler Upgrade Scheme (BUS) provides a £7,500 voucher towards the cost of the installation. Greenmotion handles all the paperwork for you. We apply for the voucher, and the amount is deducted directly from your final invoice, so you never have to wait for a refund.
Usually, No. In most cases, installing an air source heat pump is considered "Permitted Development". However, to qualify, the unit must be at least 1 metre from your boundary and used for heating only. If you live in a Listed Building or Conservation Area, we will help you check with the local council.
No. We install a dedicated Vaillant uniSTOR cylinder (150L - 250L). The heat pump recharges this cylinder rapidly. Unlike older systems, the Vaillant heats water to 70°C+ naturally, killing Legionella bacteria without needing an expensive immersion heater backup.
Yes, if designed correctly. With a SCOP of roughly 4.0, the heat pump turns 1 unit of electricity into 4 units of heat. By switching to a smart tariff like Octopus Cosy, you can expect to save 20-30% on your heating bills compared to a gas boiler.