Heat Pump vs Oil Boiler vs Gas BoilerAn honest guide for Andover, Marlborough & Hungerford homeowners
Your heating system is the biggest energy decision you'll make. This guide cuts through the hype and gives you the facts — including when a heat pump isn't the right answer.
The Heating Crossroads
Why this decision matters more than ever for Hampshire homeowners
If you live in Andover, Marlborough, Hungerford or the surrounding villages, there's a good chance your heating system is approaching — or past — the point where replacement makes more sense than repair. Perhaps your oil boiler is 15 years old and getting thirsty. Maybe your gas boiler is due its annual service and you're wondering whether to invest in it again. Or you've heard about heat pumps and the £7,500 government grant and want to understand whether the numbers add up.
This guide is written from hands-on experience. As a professional plumber based in Great Bedwyn, I work across the SN8, SP10, SP11 and RG17 postcodes and advise homeowners on heating upgrades every week. I've seen heat pumps transform homes — and I've seen them installed badly in properties that weren't ready. I want to give you the honest picture so you can make the right choice for your home.
Many rural properties around here are off the gas grid and rely on oil, which makes the heat pump question particularly relevant. Conservation areas in Marlborough, listed cottages in Hungerford, and military housing in Tidworth all bring different considerations. This isn't a one-size-fits-all answer — but by the end of this guide you'll know which direction suits your property, budget and priorities.
How Each System Works
A 60-second explanation of each technology — no jargon, just the essentials
Air Source Heat Pump
Works like a fridge in reverse. An outdoor unit extracts heat from the air — even in winter — and concentrates it to heat water. That water flows through your radiators or underfloor heating. Uses electricity, but for every 1kW of electricity it produces 3–4kW of heat.
Oil Boiler
Burns kerosene (heating oil) in a combustion chamber to heat water directly. The hot water circulates through radiators. Common in rural Hampshire where mains gas isn't available. Requires an oil tank (usually outside) and regular deliveries.
Gas Boiler
Burns mains natural gas to heat water. The most common heating system in the UK but not available in many rural areas around Andover, Marlborough and Hungerford. Compact, familiar technology with a well-established supply chain.
Head-to-Head Comparison
Real numbers, not marketing spin — based on a typical 3-bed Hampshire home
| Factor | Heat Pump | Oil Boiler | Gas Boiler |
|---|---|---|---|
| Installation Cost | £10,000–£15,000 | £3,000–£5,000 | £2,500–£4,000 |
| After BUS Grant | £2,500–£7,500 | N/A | N/A |
| Annual Running Cost | £800–£1,200 | £1,400–£2,000 | £700–£1,000 |
| Efficiency | 300–400% | 85–93% | 90–94% |
| Lifespan | 20–25 years | 15–20 years | 12–15 years |
| Annual Service Cost | £100–£150 | £100–£200 | £80–£120 |
| Carbon Emissions | ~75% less | Highest | Medium |
| Fuel Price Volatility | Low (electricity) | High (oil market) | Medium (gas market) |
| Space Required | Outdoor unit + cylinder | Oil tank + boiler | Wall-mounted boiler |
| Planning Permission | Usually permitted dev. | Usually not needed | Not needed |
Key Takeaway
On upfront cost alone, gas and oil win. But factor in the £7,500 BUS grant, lower running costs, longer lifespan, and rising fossil fuel prices — and heat pumps often work out cheaper over 10–15 years. The critical variable is your property: insulation quality determines whether a heat pump delivers those headline efficiency numbers or falls short.
When Heat Pumps Work Brilliantly
The properties and situations where heat pumps are the clear winner
Well-Insulated Properties
Homes with cavity wall insulation, loft insulation (270mm+), and double glazing are ideal. The less heat your home loses, the less work the heat pump needs to do — meaning higher efficiency and lower bills.
Local example: Modern estates in Andover (SP10) and Tidworth (SP9) typically have excellent insulation and are perfect candidates.
Underfloor Heating
Heat pumps produce lower temperature water (35–45°C) which is exactly what underfloor heating needs. This is the single best combination for efficiency — your heat pump runs at its highest COP and your home feels beautifully warm.
Ideal for: New builds, extensions, and barn conversions around Marlborough and Hungerford where UFH is increasingly popular.
Oil Boiler Replacements
If you're currently on oil and your boiler is 15+ years old, a heat pump is the strongest financial case. Oil costs £1,400–£2,000/year vs £800–£1,200 for a heat pump, and the BUS grant closes the installation cost gap significantly.
Many off-gas villages: Shalbourne, Inkpen, Burbage, Ramsbury and most SN8/RG17 villages have no mains gas — making this a common scenario.
New Builds & Major Renovations
If you're building from scratch or doing a significant renovation, design the property around a heat pump from the start. Correct insulation, right-sized radiators, and good pipework make installation simpler and cheaper.
Planning note: From 2025, new builds are effectively required to install low-carbon heating. Heat pumps are the standard choice.
The Success Formula
Good insulation + right-sized emitters + correct design = happy heat pump owner
All three elements matter. A heat pump in a well-insulated home with tiny radiators will still underperform. This is why we always do a full heat-loss survey before quoting — it's the foundation of a successful installation.
When Heat Pumps Struggle
Honest about the situations where a heat pump may not be the best first step
I could sell more heat pumps by glossing over this section. But a poorly matched heat pump leads to high bills, cold rooms, and a disillusioned homeowner — which helps nobody. Here are the scenarios where I'd recommend caution or an alternative approach:
Poorly Insulated Solid-Wall Properties
Many period cottages around Marlborough (SN8) and Hungerford (RG17) have solid stone or brick walls with no insulation. Heat leaks out faster than a standard heat pump can replace it efficiently. The pump runs at higher temperatures, efficiency drops to 200% or below, and running costs approach oil levels. Solution: insulate first, then install a heat pump.
Small Radiators Throughout
Older systems were designed for 70–80°C water from a boiler. Heat pumps work best at 35–45°C. If your radiators are too small, they can't deliver enough warmth at lower temperatures. Upgrading radiators adds £2,000–£4,000 to the project — worthwhile, but needs factoring into your budget.
Listed Buildings in Conservation Areas
Parts of Marlborough town centre, Ramsbury, and several Hungerford streets are in conservation areas. External wall insulation is often prohibited, and the outdoor heat pump unit may need planning permission or careful siting. It's not impossible — I've installed heat pumps in listed properties — but it requires more planning and potentially higher costs.
Very Tight Budget
Even with the £7,500 BUS grant, a heat pump installation typically costs £2,500–£7,500 out of pocket. If your oil boiler has failed and you need heating this week with minimal outlay, a new oil boiler at £3,000–£5,000 (no grant) may be the pragmatic choice. There's no shame in that — and you can plan for a heat pump next time.
Will's Honest Note
About 1 in 4 enquiries I get for heat pumps, I recommend doing something else first — usually improving insulation or upgrading radiators. It might cost me a sale today, but it means when you do get a heat pump, it works properly. A £12,000 heat pump in a drafty cottage with tiny radiators is £12,000 wasted. A £5,000 insulation upgrade followed by a heat pump two years later is an investment that pays back for decades.
When Oil or Gas Still Makes Sense
There are genuine scenarios where traditional boilers remain the right choice
Oil Boiler: Replace Like-for-Like
- Your property needs major insulation work you can't afford yet
- You need a boiler replacement urgently (failed mid-winter)
- Budget is under £5,000 and you need heating now
- You plan to sell the property within 2–3 years
Tip: A modern condensing oil boiler (93% efficient) is still a significant upgrade from a 20-year-old unit running at 75–80%.
Gas Boiler: Still Competitive
- You have mains gas and your current boiler needs replacing
- Gas is currently the cheapest fuel per kWh of heat
- Your property has space constraints (no room for outdoor unit)
- You're on a strict budget and running costs are already manageable
Note: New gas boiler installations may face restrictions from 2035. Consider a heat pump for your next replacement cycle.
The Stepping-Stone Approach
For many homeowners around Andover and Marlborough, the smartest plan is phased:
Replace failing boiler with modern oil/gas unit. Improve loft insulation.
Add wall insulation, upgrade key radiators, improve glazing where possible.
Install heat pump into a properly prepared home. Maximise efficiency from day one.
BUS Grant & The Financial Case
£7,500 off your installation — here's how it works
You CAN Apply If:
- Your property is in England or Wales
- You have a valid EPC (Energy Performance Certificate)
- You're replacing an existing fossil fuel heating system
- Your installer is MCS certified
- The property is not a new build (must have existing heating)
You CANNOT Apply If:
- The property is a new build
- You don't have a valid EPC
- The installer isn't MCS certified
- You've already received a BUS grant at this property
- You're installing a replacement heat pump (like-for-like)
Typical Cost Breakdown: Oil → Heat Pump
Based on a 3-bed detached house near Andover with reasonable insulation
Payback Calculation
Saving £500–£800/year on fuel vs oil, with an out-of-pocket cost of £2,500–£7,500 after the grant, typical payback is 3–10 years. After that, you're saving money every year for the remaining 10–15 years of the heat pump's life. That's a potential £5,000–£12,000 lifetime saving.
Which Heating System Is Right for You?
Work through these questions to find your answer
Do you have mains gas?
Yes → Your options are gas boiler or heat pump
Gas is currently cheapest to run. Heat pump wins on carbon and long-term costs.
No → Your options are oil boiler or heat pump
Most off-gas homes in SP10/SP11/SN8/RG17 are in this category. Heat pump is usually the stronger choice here.
How well insulated is your property?
Good (EPC C or above)
Heat pump will work brilliantly. Proceed to question 3.
Average (EPC D)
Heat pump will work but may need radiator upgrades. Get a heat-loss survey first.
Poor (EPC E–G)
Insulate first. Replace boiler if needed now. Plan heat pump for later.
What's your budget?
£5,000+ (after grant)
Full heat pump installation is within reach. Excellent long-term investment.
£3,000–£5,000
Heat pump possible with BUS grant. May need smaller system or fewer upgrades.
Under £3,000
New oil/gas boiler is more realistic now. Save towards a heat pump next time.
What type of heating do you have or want?
Underfloor heating or large radiators
Perfect for a heat pump. This is the ideal combination for maximum efficiency.
Standard/small radiators
Budget for radiator upgrades (£2,000–£4,000) or consider a traditional boiler for now.
Quick Summary
Choose Heat Pump
Good insulation + budget for grant contribution + off-gas or eco-minded
Choose Oil Boiler
Off-gas + poor insulation + tight budget + need heating urgently
Choose Gas Boiler
On mains gas + tight budget + space constraints + lowest running costs now
Local Considerations for Our Area
What makes the Andover, Marlborough & Hungerford area different
Off-Gas Grid Prevalence
A huge proportion of homes in the SN8 and RG17 postcodes have no mains gas. Villages like Shalbourne, Inkpen, Ramsbury, Burbage and Chilton Foliat rely almost entirely on oil or LPG. This makes the heat pump business case even stronger — you're comparing against expensive oil, not cheap gas.
Even in Andover (SP10/SP11), many properties on the outskirts and surrounding villages like Upper Clatford, Appleshaw and the Wallops are off the gas grid.
Conservation Areas & Listed Buildings
Marlborough High Street, parts of Ramsbury, central Hungerford and many Kennet Valley villages have conservation area restrictions. External wall insulation may be prohibited, and outdoor heat pump units may need screening or specific siting.
This doesn't rule out heat pumps — but it means working with the planners and choosing quieter, more compact units. I've successfully installed heat pumps in several conservation area properties.
Stone & Brick Cottage Construction
Many properties across the area are built from local stone, flint, or old brick with solid walls. These have higher heat loss than cavity-wall houses. Internal wall insulation is often the best option, adding around £5,000–£8,000 but dramatically improving heat pump performance.
Thatched cottages around Pewsey (SN9) and the Wallops (SP10) need specialist insulation advice to avoid moisture issues.
Military Housing (Tidworth/Bulford)
Service families in Tidworth (SP9) and Bulford often live in MOD housing where heating upgrades are managed by DIO. For privately owned homes in the area, the housing stock is mixed — 1960s–2000s builds are generally well-suited to heat pumps.
Private homeowners near the garrison benefit from good infrastructure and newer building standards that make heat pump installation straightforward.
Frequently Asked Questions
Common questions from homeowners across Andover, Marlborough & Hungerford
Can I replace my oil boiler with a heat pump?
Yes — and you may qualify for the £7,500 BUS grant to help cover costs. Your property will need reasonable insulation and ideally larger radiators or underfloor heating. We carry out a full heat-loss survey before recommending a switch so you know exactly what to expect.
Are heat pumps worth it in older Hampshire cottages?
It depends on the property. Well-insulated period homes with upgraded radiators can work brilliantly with heat pumps. However, solid-wall stone cottages with poor insulation may need significant upgrades first. We always give an honest assessment — sometimes improving insulation first delivers better value.
What is the BUS grant and am I eligible?
The Boiler Upgrade Scheme provides £7,500 towards air source heat pump installation. You need an EPC (Energy Performance Certificate), your property must not be a new build, and the installer must be MCS certified. The grant is applied at point of installation so you never need to fund the full amount.
How much does a heat pump cost to run compared to oil?
A well-installed heat pump with a COP of 3.0 typically costs £800–£1,200 per year to heat a 3-bed home. Oil heating for the same property runs £1,400–£2,000 depending on oil prices. Gas is currently the cheapest at £700–£1,000 but prices fluctuate. The gap narrows further as electricity tariffs fall for heat pump users.
Do heat pumps work in cold weather?
Modern air source heat pumps work efficiently down to -15°C and below. Even on the coldest Hampshire winter nights they continue producing heat. Performance drops slightly in extreme cold, but annual efficiency (known as SCOP) accounts for this. Ground source heat pumps are unaffected by air temperature.
How long does it take to install a heat pump?
A typical air source heat pump installation takes 2–4 days including the outdoor unit, cylinder, pipework modifications, and commissioning. If you also need radiator upgrades or underfloor heating, allow a week. A qualified installer handles the full project from survey through to commissioning and grant paperwork.
Will a heat pump heat my home as well as my boiler?
Yes, but differently. Boilers produce short bursts of very hot water. Heat pumps deliver lower-temperature heat over longer periods — more like a constant, gentle warmth. Most people find this more comfortable once they adjust. The key is correct system design: right-sized radiators, proper flow temperatures, and good controls.
Should I get insulation before a heat pump?
Usually yes. Better insulation means a smaller, cheaper heat pump and lower running costs. We recommend addressing loft insulation, cavity walls, and draughts before installation. In Marlborough and Hungerford, many homes benefit from internal wall insulation where external isn't possible in conservation areas.
Ready for Honest Heating Advice?
Book a no-obligation survey and get a straightforward recommendation for your property. No hard sell, no pressure — just expert advice from your local plumber.
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