Choosing a heating system is one of the biggest decisions you can make as a homeowner. Get it right, and you’ll have reliable, affordable warmth for decades. Get it wrong, and you’ll face high running costs, an undersized system, or expensive changes down the line.
For Cornwall homeowners, the choice is more nuanced than it is for most of the UK. A significant proportion of homes here sit off the mains gas grid, meaning oil is not a fallback option but often the current reality. And with heat pumps increasingly on people’s radar, it’s worth understanding what genuinely suits a Cornish property before making any decisions.
This guide walks through the three main options in plain terms – including the key differences in a heat pump vs gas boiler comparison – covering how they work, what they cost, and which types of home they suit best.
Why Cornwall is Different
Around 35,000 homes in Cornwall are not connected to the mains gas grid, meaning roughly 14% of households here rely on heating oil or liquefied petroleum gas (LPG) for their heating*. Nationally, the figure is closer to 15% of all domestic properties, but Cornwall’s rural character, older housing stock, and dispersed settlements mean off-grid heating is a far more common reality here than in most English counties.
That changes the conversation considerably – especially when comparing heat pump vs gas boiler options in areas where gas simply isn’t available. For a homeowner in, say, Guildford, comparing oil and gas is largely academic: mains gas is almost certainly available. For someone in a farmhouse near Helston or a cottage on the Lizard, oil may be what they currently run on, and understanding the alternatives properly is a genuinely practical question.
How Each System Works
Oil boilers
An oil boiler works in much the same way as a gas boiler, burning fuel to heat water that circulates through your radiators and hot water cylinder. The key difference is that oil is stored in a tank on your property (typically in the garden) and delivered by a tanker when you need to top up. Modern condensing oil boilers are highly efficient, and the system is well-understood by engineers across Cornwall.
Gas boilers
A mains gas boiler connects directly to the national grid, so there’s no tank to manage and no delivery to arrange. You simply use gas as you need it and pay for it on your bill. Combination (combi) boilers heat water on demand; system or regular boilers use a stored hot water cylinder. For properties within reach of the gas network, gas has traditionally been the most common and cost-effective option, which is why heat pump vs gas boiler is such a common comparison for homeowners weighing up long-term running costs. However, the proportion of Cornwall homes without mains gas is considerably higher than the national average*, making this a non-starter for many local homeowners.
Air source heat pumps
A heat pump doesn’t burn anything. Instead, it extracts heat from the outside air (even in cold weather) and uses it to warm your home and hot water. It runs on electricity, and because it moves heat rather than generating it, it typically produces more energy than it consumes. Air source heat pumps (ASHPs) are installed outside the property and connected to your existing or upgraded radiator circuit or underfloor heating. Our team at Blue Flame installs and services both air source and ground source heat pumps across Cornwall, and is MCS certified, a requirement for accessing government grant funding.
What About Older and Rural Properties?
This is the question that matters most for a large number of Cornwall homes.
Much of Cornwall’s housing stock is old (granite-built farmhouses, stone terraces, Victorian cottages) and many of these properties sit off the gas grid. They were built long before modern insulation standards, often with solid walls, single glazing, and relatively high heat loss.
For oil boilers, this is largely where they came from and what they were designed for. A well-maintained condensing oil boiler will heat a draughty farmhouse effectively. The trade-off is ongoing fuel costs, storage requirements, and the fact that oil is a fossil fuel with an uncertain long-term future as regulations around heating tighten.
For gas boilers, rural Cornwall often rules this out entirely due to lack of mains supply.
For heat pumps, the picture requires honest assessment. Homes with solid walls or single glazing may need upgrades, such as cavity wall insulation or double glazing, to get the most out of a heat pump in terms of performance and cost savings. Additionally, older radiators often struggle to deliver sufficient heat at the lower flow temperatures required by air source heat pumps, and may need to be upsized or replaced with low-temperature models or underfloor heating.
That said, heat pumps in older properties are far from impossible. Many UK homes keep their existing radiators – larger ones might be installed in key rooms to improve heat output, and a thorough survey can establish what’s needed before any commitment is made. The key is having the system properly designed for your specific property rather than relying on a generic spec.
For listed buildings or properties in conservation areas, additional planning considerations may apply, and it’s worth discussing these with an installer early.
Which System Is Right For You?
There’s no single answer that fits every Cornwall home, but here’s a simple way to think about it:
Oil boiler may be the right choice if your property is off-grid, older, and not yet well-insulated, particularly if you’re replacing an existing oil system on a budget and want a straightforward, proven solution in the short term.
Gas boiler is only relevant if you’re connected to the mains gas network. If you are, it remains a practical option, though it’s worth being aware that the long-term direction of travel is away from fossil fuel heating.
Air source heat pump is worth serious consideration if you’re off-grid (making oil your current alternative), if your property has reasonable insulation or you’re willing to invest in improvements, and if you want to reduce your running costs and carbon footprint over the long term. With the right specification, it can work well in a range of Cornwall property types — including older homes.
The Boiler Upgrade Scheme: Worth Knowing About
If you’re considering a heat pump, the government’s Boiler Upgrade Scheme (BUS) is currently one of the most significant financial incentives available to homeowners. The scheme provides £7,500 off the cost and installation of an air source heat pump, and £7,500 off a ground source heat pump – applied directly to your installation cost by your installer.
The scheme has been extended until at least 2030, with funding increasing each year, giving homeowners greater certainty that support will remain available. Crucially, biomass boilers are eligible for a £5,000 grant, but only in properties that are both in a rural location and not connected to the gas grid – a combination that fits a meaningful proportion of Cornwall homes.
To access the grant, your installation must be carried out by an MCS-certified installer. Blue Flame holds MCS registration and can apply for the Boiler Upgrade Scheme on your behalf as part of the installation process. We’ll be publishing a dedicated guide to the Boiler Upgrade Scheme shortly (covering eligibility, what to expect, and how the process works) so check back for that if you’d like more detail.
Get Tailored Advice for Your Cornwall Home
The right heating system depends on your property, your budget, and where you want to be in five or ten years. There’s no substitute for someone who knows what they’re looking at.
Our team at Blue Flame has been helping Cornwall homeowners, many of them off the gas grid, with heating installations, renewables and advice for years. Whether you’re replacing an aging oil boiler, exploring heat pumps for the first time, or simply trying to understand your options, our team can assess what suits your home and give you an honest steer.
Call us on 01326 378122 or get in touch online to speak to one of our team in Penryn.