Looking for an MCS-certified Vaillant heat pump installer in Wiltshire? You are in the right place.
At Infinity Energy Services we have been designing and installing renewable heating, solar, and battery systems since 2011, with more than 6,500 installations completed across the south of England.
We are one of the most-experienced Vaillant aroTHERM plus installers serving Wiltshire from our head office in Hampshire.
We apply for the £7,500 Boiler Upgrade Scheme grant on your behalf – some properties will get £9,000 from July – and you can take advantage of 0% VAT until at least 31 March 2027.
This page is a deep dive into one product: the award-winning Vaillant aroTHERM plus, the heat pump we recommend most often when budget allows.
Read on for honest cost figures, real running-cost arithmetic, and the technical detail that matters for your home.
If you would prefer to skip ahead, click the button below, or call us on 0800 909 8882 for a tailored quotation.
– Last updated 8 May 2026 –
TABLE OF CONTENTS
• Why Vaillant aroTHERM plus?
• Vaillant aroTHERM plus Technical Details
• Choosing the Right Size
• How Much Does a Vaillant aroTHERM plus Cost?
• Typical Running Costs in Wiltshire
• BUS Grant & 0% VAT
• Will An aroTHERM plus Work in My Wiltshire Home?
• Pairing Your Heat Pump with Solar & Battery
• Our Installation Process
• May 2026 Update
• Areas We Serve in Wiltshire
• Frequently Asked Questions
• Get a Free Vaillant Heat Pump Quote
Why Vaillant aroTHERM plus Is Our Premium Recommendation in Wiltshire
Infinity Energy Services is brand-independent. We specify the right heat pump for your property after a heat-loss survey, not before. That said, when budget allows, the Vaillant aroTHERM plus is the model we install most frequently in Wiltshire.
It earns that recommendation on a combination of three things:
- A market-leading flow temperature of 75 °C (which often eliminates the need to upgrade existing radiators).
- The natural R290 refrigerant (future-proof against the F-Gas Regulation).
- Quiet Mark accreditation on the 3.5, 5, 7, and 12 kW outputs (essential for tighter Wiltshire plots).
Vaillant has been making heating products for over 140 years and heat pumps for over 40, with manufacturing in the EU and a UK service-and-training base in Belper, Derbyshire.
Where the Vaillant aroTHERM plus stands out
- Highest flow temperature in its class: up to 75 °C, often eliminating the need for radiator upgrades in older Wiltshire homes.
- Natural R290 refrigerant with a Global Warming Potential of just 3: future-proof against the F-Gas Regulation.
- A+++ energy efficiency at 35 °C flow; A++ at 55 °C; SCOP up to 5.03 (10 kW model at 35 °C flow).
- Quiet Mark accreditation on 3.5, 5, 7, and 12 kW outputs – sound power as low as 54 dB.
- Designed and tested in Vaillant’s own climate chambers down to -25 °C.
- Up to a seven-year manufacturer warranty when paired with a Vaillant cylinder.
Vaillant in the context of UK adoption
Vaillant is one of the most-installed heat pump brands in the UK, with more than 200,000 Vaillant heat pumps fitted worldwide.
The manufacturer’s own published testing has shown energy savings of up to 43% when the aroTHERM plus replaces an oil or LPG system in retrofit projects – the saving most relevant to off-grid Wiltshire villages.
Real-world performance always depends on heat-loss design, emitter sizing, and commissioning, but it is fair to say the aroTHERM plus sits at the top end of what is technically possible in a domestic heat pump today.
Vaillant aroTHERM plus: The Technical Detail That Matters
If you are weighing one heat pump against another, four numbers matter more than the rest: the refrigerant, the flow temperature, the SCOP, and the sound output. Here is what each one means in practice for a Wiltshire home.
R290 refrigerant
R290 is propane, the same natural refrigerant used in domestic fridges and heat-pump tumble-driers. Its Global Warming Potential is 3, compared with 675 for R32 and 2,088 for the older R410a. That has three practical consequences for the homeowner.
First, the system is exempt from the EU F-Gas Regulation phase-down, so you will not be facing a more expensive refrigerant retrofit later in the system’s life.
Second, R290 supports higher flow temperatures – up to 75 °C – which means existing radiators in older Wiltshire properties can usually stay in place.
Third, it operates over a wider temperature envelope, from -25 °C to +46 °C in heating mode. That envelope comfortably covers Wiltshire’s recorded climate range with margin to spare.
Flow temperature, SCOP, and sound output
Flow temperature is the temperature of the water leaving the heat pump and arriving at the radiators. Lower flow temperatures give a better SCOP (Seasonal Coefficient of Performance), but require larger emitters. The aroTHERM plus is rated across a 35-75 °C range; sensible Wiltshire installations sit at 45-55 °C, which gives a real-world SCOP of around 3.5-4.0 in a well-designed system.
The table below is the manufacturer’s published SCOP at five flow temperatures, rated to EN 14511. Real-world figures will be a touch lower, but the relative differences between models hold.
Sound levels at distance
Wiltshire homeowners regularly ask whether their neighbour will notice the unit. The aroTHERM plus 5 kW radiates 46 dB(A) at 1 metre, 36 dB(A) at 3 metres, and 32 dB(A) at 5 metres. By the time the sound reaches the boundary of a typical Swindon or central Salisbury garden, it is quieter than a normal conversation in the next room.
Quiet Mark accreditation matters because the MCS 020 noise calculation must show below 37 dB(A) at the nearest neighbour’s habitable-room window for permitted-development rules to apply. The aroTHERM plus is one of the few heat pumps that comfortably hits that envelope on small terraced or semi-detached plots.
Operating envelope
The aroTHERM plus operates from -25 °C to +46 °C in heating mode, and from -20 °C to +46 °C in domestic hot water mode. Wiltshire’s coldest recorded winter days rarely fall below -7 °C on the higher ground of Salisbury Plain and the Marlborough Downs, and its hottest summer days reach the low to mid 30s. The system is sized with comfortable headroom at both ends.
Choosing the Right Size and Indoor Configuration
Heat pump sizing is the single biggest determinant of real-world running costs. Specify too small and the system relies on the auxiliary electric heater for peak demand; specify too large and it cycles inefficiently.
Every Infinity Energy Services quote starts with a full MCS-compliant heat-loss calculation, room by room. The chart below maps the five aroTHERM plus outputs to typical Wiltshire property archetypes; this is indicative only, and the final size is set by the survey.
uniTOWER, hydraulic module, or heat-pump interface – which is right for me?
Vaillant offers three indoor configurations to pair with the outdoor aroTHERM plus. Each one suits a different kind of Wiltshire property:
- uniTOWER: an integrated 190-litre cylinder with hydraulic components, a modulating electric back-up heater, and a 3-way diverter valve all in a single fridge-freezer-sized unit. Best for new builds, properties where the existing cylinder is end-of-life, and homes where space is at a premium.
- Hydraulic module + uniSTOR cylinder: a wall-mounted hydraulic module with a separate Vaillant uniSTOR heat-pump cylinder. Best for homes with higher hot-water demand than the uniTOWER’s 380 litres of usable output, or where the cylinder needs to live in a different room from the hydraulics.
- Heat-pump interface: a bare interface allowing a fully bespoke installation with existing components retained. Best for retrofits where the existing cylinder is in good condition and a non-standard hydraulic layout is required.
All three configurations are commissioned and controlled through Vaillant’s sensoCOMFORT weather-compensating room thermostat (or the wireless sensoCOMFORT RF), with an optional sensoNET internet gateway and the sensoAPP smartphone app for remote monitoring.
How Much Does a Vaillant aroTHERM plus Cost in Wiltshire in 2026?
The headline range, before any grant, for a fully fitted Vaillant aroTHERM plus heat pump installation in Wiltshire is typically £11,000-£16,000 in 2026.
The uplift over the all-brand average reflects the higher specification of the Vaillant unit, the uniTOWER or uniSTOR cylinder, and the longer-warranty parts that come with the Vaillant ecosystem.
After the £7,500 BUS grant, most Wiltshire homeowners pay £3,500-£8,500. From July 2026, oil and LPG-heated homes – very common across rural Wiltshire, particularly in the Vale of Pewsey, the Marlborough Downs, and the Cranborne Chase – qualify for an uplifted £9,000 grant, which can take the net cost as low as £2,000.
These ranges are indicative. Final price depends on heat-loss results, radiator and pipework upgrades, hot-water cylinder specification, and any building work required (such as condensate drainage).
Every Infinity Energy Services quote is fixed in writing before any work starts.
How a Vaillant install compares with a new gas boiler
A like-for-like premium gas boiler replacement in Wiltshire is typically £3,500-£5,500 fully fitted in 2026. After the £7,500 BUS grant and 0% VAT, a Vaillant aroTHERM plus typically lands in the £3,500-£8,500 range – broadly comparable to the boiler, but with a 20-year design life, no exposure to gas price spikes, and a fully decarbonised heating system.
Compared with replacing an oil boiler in rural Wiltshire, the calculation is more favourable still. The aroTHERM plus typically saves £500-£1,000 a year in running costs, and the £9,000 BUS uplift available from July 2026 closes the upfront gap to near zero in many cases. A heat pump installation, viewed as a 20-year investment, returns its capital cost many times over.
Running Costs in Wiltshire on the Live Ofgem Cap
Honest figures, using the Q2 2026 Ofgem energy price cap (1 April to 30 June 2026): gas at 5.74p/kWh, electricity at 24.67p/kWh, an A-rated gas boiler running at 88% efficiency, an oil boiler at 84% efficiency on heating oil at 75p per litre, and a Vaillant aroTHERM plus at the published SCOP figures.
- Gas boiler effective heat cost: 5.74p ÷ 0.88 = 6.5p per kWh of heat delivered.
- Oil boiler effective heat cost: roughly 7.5p per kWh of heat delivered (based on 75p per litre and 10.35 kWh per litre).
- aroTHERM plus at SCOP 3.0: 24.67p ÷ 3.0 = 8.2p per kWh.
- aroTHERM plus at SCOP 3.5 (sensible target with good design): 24.67p ÷ 3.5 = 7.0p per kWh.
- aroTHERM plus at SCOP 4.0 (achievable on low-flow installs at 35-45 °C): 24.67p ÷ 4.0 = 6.2p per kWh.
- Removing your gas meter saves around £105 a year in standing charges.
- Pair the heat pump with solar PV and a battery, and a meaningful share of your heat is generated for free.
The bottom line: in a well-designed Wiltshire installation, the aroTHERM plus delivers heat at a cost broadly comparable to mains gas, and significantly cheaper than oil or LPG. For rural Wiltshire homes currently running on oil, the running-cost saving is typically £500-£1,000 a year before any solar contribution – and the homeowner is fully decoupled from oil-price volatility.
BUS Grant, 0% VAT, and the £9,000 Uplift for Oil and LPG Homes
The Boiler Upgrade Scheme (BUS) is the UK government’s flagship heat pump grant in England and Wales, administered by Ofgem.
As an MCS-certified installer, Infinity Energy Services applies for the grant on your behalf and deducts it from your invoice before you pay.
There is no separate paperwork. The grant is paid directly to us by Ofgem.
Current status (May 2026)
- £7,500 standard BUS grant for an air source heat pump, available now.
- £9,000 BUS grant for properties currently heated by oil or LPG, expected to open for applications in July 2026 and run until 31 March 2027.
- 28 April 2026: EPC requirement removed; scheme extended to 31 March 2030.
- 0% VAT on residential heat pump supply and installation, in place until at least 31 March 2027.
Rural Wiltshire contains a disproportionate number of off-gas-grid villages running on oil or LPG – places like Aldbourne, Ramsbury, Tisbury, Hindon, Mere, Maiden Bradley, Heytesbury, Codford, Broad Chalke, Cricklade, and Ashton Keynes. These properties are exactly where the £9,000 grant, the highest in the scheme’s history, combines with the largest running-cost saving to produce the strongest case to switch.
Will an aroTHERM plus Work in My Wiltshire Home?
Almost any Wiltshire property can run on a Vaillant aroTHERM plus if the system is correctly designed. What matters most is the heat-loss calculation, the choice of emitters, and the flow temperature the system is designed at. The aroTHERM plus has two specific strengths in the Wiltshire context that other heat pumps do not always match.
Older homes with smaller cast-iron radiators
Period properties in Marlborough, Bradford-on-Avon, Devizes, Salisbury, and Malmesbury often have radiators sized for a 70-80 °C gas-boiler flow. The aroTHERM plus is rated to deliver 75 °C flow when needed, which means existing radiators can frequently stay in place – a saving of several hundred pounds and several days of disruption per home. We always design at the lowest sensible flow temperature for efficiency, but the headroom is there if your house needs it.
Densely built-up terraces and semis
In Swindon, central Salisbury, and parts of Trowbridge, garden depths are short and neighbour boundaries are close. The aroTHERM plus 3.5, 5, 7, and 12 kW outputs all carry Quiet Mark accreditation, and the 5 kW model is rated at just 32 dB(A) at 5 metres – quieter than a fridge in the next room. Combined with the Sound Safe System and the floating-floor design that absorbs vibration, this makes the aroTHERM plus one of the few heat pumps comfortably installable on a tight Wiltshire plot without falling foul of the 37 dB(A) MCS 020 noise limit at the neighbour’s window.
Conservation areas and listed buildings
Listed buildings always require Listed Building Consent, and conservation areas have their own rules under Wiltshire Council’s or Swindon Borough Council’s Local Plan. Our survey covers planning status as standard. For a heat pump within a conservation area, the unit must not face a highway. Many of Wiltshire’s conservation areas – the heart of Marlborough, Bradford-on-Avon’s town centre, the Cathedral Close in Salisbury, the National Trust villages of Lacock and Castle Combe – accommodate sympathetic side- or rear-of-property installations without trouble.
Pairing Your Vaillant Heat Pump with Solar, Battery, and a Smart Tariff
A Vaillant aroTHERM plus is SG-Ready, which means it can be controlled by a smart power-grid signal or a time-of-use electricity tariff. Combined with solar PV and battery storage – both of which Infinity Energy Services installs as a single accountable contractor – the heat pump can shift its hot-water generation into the cheapest hours of the day, and use solar generation directly during the warmer months.
For a Wiltshire homeowner with a typical 4 kW solar array, a 5 kWh battery, and a 7 kW aroTHERM plus, annual heating-electricity costs can be reduced by 30-50% compared with the heat pump on a flat tariff alone. The whole-home approach also means a single survey, single design, and single point of warranty contact – not three separate trades blaming each other when something needs adjusting.
See our companion Wiltshire pages for solar and battery storage:
Our Installation Process for Wiltshire Homeowners
From first enquiry to commissioning, our process is structured to remove uncertainty.
- FREE REMOTE QUOTE: Share your property details and we will provide an indicative cost within 24 hours.
- ON-SITE SURVEY AND HEAT-LOSS CALCULATION: A full MCS-compliant room-by-room heat-loss assessment, typically 60-90 minutes.
- DETAILED SYSTEM DESIGN: Heat pump model and output, hot-water cylinder specification, radiator schedule, pipework route, controls strategy.
- FIXED-PRICE QUOTE: BUS grant and 0% VAT applied; nothing to pay upfront beyond a small deposit.
- BUS APPLICATION SUBMITTED: We handle this with Ofgem on your behalf.
- INSTALLATION: Typically two to five days, with minimal disruption to your home.
- COMMISSIONING AND HANDOVER: A walkthrough of the controls, a performance check, and a complete document pack.
- AFTERCARE: Service plans available; insurance-backed workmanship guarantee through RECC.
Total time from accepted quote to commissioned heat pump in Wiltshire is typically four to six weeks, depending on the season.
May 2026 Update
Here is your latest monthly news regarding Vaillant and heat pumps in Wiltshire:
- £9,000 BUS grant for oil and LPG homes confirmed for July 2026 launch – the highest grant level in the scheme’s history. Rural Wiltshire homes off the gas grid are best placed to benefit.
- 28 April 2026 BUS rule changes now in force: EPC requirement scrapped; scheme extended to 31 March 2030.
- Q2 2026 Ofgem energy price cap (1 April to 30 June): gas 5.74p/kWh, electricity 24.67p/kWh. The Q3 cap is announced by Ofgem in late May.
- 0% VAT on residential heat pump installations confirmed until at least 31 March 2027.
- Vaillant aroTHERM plus current lead time in Wiltshire: four to six weeks from accepted quote to commissioned system.
Areas We Serve in Wiltshire
We install Vaillant aroTHERM plus heat pumps for homeowners across the whole of Wiltshire, including all of the following towns and villages:
- Salisbury
- Swindon
- Trowbridge
- Chippenham
- Devizes
- Warminster
- Melksham
- Westbury
- Calne
- Corsham
- Bradford-on-Avon
- Amesbury
- Marlborough
- Tidworth
- Royal Wootton Bassett
- Highworth
Plus all the surrounding villages: Lacock, Castle Combe, Aldbourne, Ramsbury, Tisbury, Mere, Cricklade, and many more. Wherever you are in Wiltshire, we cover you.
Frequently Asked Questions
Yes. It is a premium-tier air source heat pump using natural R290 refrigerant, with a SCOP of up to 5.03, A+++ ErP energy rating at 35 °C flow, and Quiet Mark accreditation on the 3.5, 5, 7, and 12 kW outputs. It is one of the most efficient and quietest heat pumps on the UK market, and the best-suited Vaillant model for the majority of Wiltshire homes.
In 2026, a Vaillant aroTHERM plus installation in Wiltshire typically costs £11,000-£16,000 fully fitted, before any grant. After the £7,500 BUS grant, most homeowners pay £3,500-£8,500. From July 2026, oil and LPG-heated homes qualify for an uplifted £9,000 BUS grant, taking the net cost as low as £2,000 in some cases.
The 5 kW model is Quiet Mark accredited and rated at 54 dB sound power, equivalent to 46 dB(A) at 1 metre, 36 dB(A) at 3 metres, and 32 dB(A) at 5 metres – quieter than a normal conversation. This makes it suitable for densely built-up Wiltshire areas including Swindon terraces and central Salisbury.
Vaillant heat pumps are typically rated for 15-20 years with annual servicing. The compressor and key parts are designed to a 20+ year life. The hot-water cylinder is usually rated for 25 years.
Vaillant aroTHERM plus heat pumps come with a two-year standard warranty, extendable to between two and seven years depending on installer accreditation tier and whether the installation is registered with a Vaillant cylinder. We will confirm the exact warranty available to you at survey stage.
Yes. The aroTHERM plus is MCS-listed and qualifies in full for the BUS grant when installed by an MCS-certified contractor like Infinity Energy Services. From July 2026, oil and LPG-heated properties qualify for an uplifted £9,000 grant.
Sometimes – but less often than with most heat pumps. The aroTHERM plus is rated to deliver flow temperatures up to 75 °C, which means existing radiators in older Wiltshire homes can frequently stay in place. Our heat-loss calculation specifies, room by room, exactly which radiators (if any) need upsizing.
Yes. The aroTHERM plus operates from -25 °C to +46 °C in heating mode, well outside the range Wiltshire ever experiences. R290 refrigerant maintains efficiency at low temperatures more effectively than older R32 refrigerants.
In most cases, no. Air source heat pumps are classed as permitted development under Class G of the General Permitted Development Order (as amended on 29 May 2025), provided MCS Planning Standards are met. Listed buildings always require Listed Building Consent, and conservation area installations face additional restrictions – we cover this as part of our survey.
Yes. The aroTHERM plus is SG-Ready and integrates with photovoltaic systems and battery storage. Infinity Energy Services installs solar, battery, EV chargers, and heat pumps as a single coordinated package, designed and commissioned together for maximum efficiency.
Get a Free Vaillant Heat Pump Quote in Wiltshire
If a Vaillant aroTHERM plus is on your shortlist for your Wiltshire home, the next step is straightforward. Request a free no-obligation heat pump installation quote from Infinity Energy Services and we will give you an indicative cost within 24 hours, followed by a detailed on-site survey at a time that suits you.
We design every system to deliver real-world efficiency, we apply for your £7,500 BUS grant (or £9,000 from July 2026 if you are on oil or LPG) and 0% VAT relief, and we stand behind the work for years afterwards through our RECC-backed workmanship guarantee.
Call us on 0800 909 8882 or click the button below to start your project.
