Which Is Better: Heat Pumps or Oil-Filled Radiators?
A heat pump is usually the better option for most homes because it provides whole-home heating far more efficiently than oil-filled radiators. According to GOV.UK, a heat pump can produce around three units of heat for every unit of electricity used, while oil-filled radiators are direct-electric resistance heaters with no efficiency multiplier. See also: BUS Grant 2026 guide, heat pump cost guide.
For most homeowners, that means this is not a close comparison if the goal is a proper long-term heating system. Oil-filled radiators can still be useful as temporary or supplementary heat, but they are rarely a sensible whole-home answer where a wet-heating retrofit is realistic. Read our complete guide to heat pumps in the UK, heat pump running costs article, and electricity vs gas cost guide. If your property is eligible, our BUS grant survey page is the route for domestic ASHP applications, subject to eligibility.
What Are the Main Differences Between the Two?
The main differences are efficiency, comfort delivery, and whether the system is temporary room heat or a permanent whole-home solution. According to GOV.UK, heat pumps typically deliver around three units of heat per unit of electricity, while direct electric oil-filled radiators convert electricity to heat on a roughly one-to-one basis.
The practical comparison looks like this:
| Feature | Heat pump | Oil-filled radiators |
|---|---|---|
| Heating logic | Moves heat efficiently | Directly converts electricity to heat |
| Typical efficiency logic | Around 3 units of heat per unit of electricity | Around 1 unit of heat per unit of electricity |
| Whole-home hot water | Yes, with suitable system design | No |
| Comfort style | Continuous whole-home heating | Localised temporary room heating |
| BUS grant | Yes, subject to eligibility | No |
| Best fit | Permanent whole-home retrofit | Short-term or supplementary heating |
Prices and services correct at time of writing — always request a current quote.
That means oil-filled radiators can be useful tools, but they are not really a substitute for a whole-home heating system. A heat pump takes more design work and more installation effort, yet it usually gives you a much better result in comfort, efficiency, and long-term control if the property is suitable.
Which One Usually Makes More Sense Financially?
A heat pump usually makes more financial sense over time because it uses much less electricity for the same delivered heat and can access the BUS grant (subject to eligibility), while oil-filled radiators cannot. According to Ofgem, eligible domestic air source heat pumps can receive a £7,500 grant subject to eligibility, and the April 2026 direct-debit electricity cap is 24.5p/kWh.
Oil-filled radiators can seem cheap because the first purchase price is low. But that is not the same as low heating cost. Once you start relying on them for regular space heating, especially across several rooms or many hours per day, the electricity use becomes expensive quickly. The comparison becomes even more favourable to the heat pump where hot water is also part of the project, where the home is occupied all day, or where solar PV and battery storage are being considered as part of broader electrification.
Typical financial decision points include:
- whether the property can access the BUS grant (subject to eligibility)
- whether the heaters are temporary backup or regular primary heating
- how many rooms need consistent heating
- whether solar or battery storage are part of the project
What Do Homeowners Most Often Get Wrong?
The most common mistake is assuming a cheap oil-filled radiator is cheap heat. According to GOV.UK, the key difference is efficiency: a heat pump can produce around three units of heat per unit of electricity, while an oil-filled radiator cannot.
Another mistake is confusing occasional-use heating with a proper heating system. Portable heaters can be useful for a cold spare room or short-term disruption, but they do not give you the comfort stability, hot-water integration, or whole-home control of a permanent system. Homeowners also sometimes compare purchase price instead of annual energy cost. That can make oil-filled radiators look more attractive than they really are when used for anything beyond temporary or localised heating.
Typical comparison mistakes include:
- comparing purchase price instead of annual running cost
- treating a temporary heater as a whole-home solution
- overlooking hot-water needs
- ignoring BUS grant eligibility
What Does This Mean in London, Surrey, and TW Homes?
In London, Surrey, and TW homes, a heat pump is usually the stronger route where the property can support a proper wet-heating retrofit and the owner wants a long-term whole-home solution. According to Ofgem (April 2026), electricity is 24.5p/kWh on the typical direct-debit cap, so using direct-electric oil-filled radiators as regular heating becomes expensive very quickly.
Oil-filled radiators can still be sensible as a temporary backup, for a home office used only occasionally, or during short-term disruption. But for most family homes in the South East, the real conversation is about moving to a whole-home heat-pump route rather than depending on localised room heaters. If the home is suitable, the heat pump is usually the more comfortable and financially coherent answer.
That is why a proper survey matters more than a quick comparison with a plug-in heater. Our heat pump size calculator guide, heat pump installation process article, and renewable energy London guide help make that decision more practical.
That matters most in older Surrey semis and London terraces where several rooms need stable background heat for long periods rather than short bursts of steady local radiant heat.
How Electromatic Can Help
If you are comparing heat pump vs oil-filled radiators, the next step is to decide whether you need a proper whole-home heating system or just short-term localised heat. According to Ofgem’s current BUS rules, eligible air source heat pumps can access the £7,500 grant, subject to eligibility, while oil-filled radiators cannot.
Electromatic can assess whether your home is a realistic candidate for an air source heat pump and whether your current use of oil-filled radiators is actually a sign that the main heating system needs replacing. We work under MCS certification via our accredited umbrella partner, and where the installation is eligible we can handle BUS grant applications for air source heat pumps, subject to eligibility. We can also coordinate ASHP, solar, and battery planning through one contractor.
That gives you a route built around whole-home comfort and efficiency instead of relying on a temporary form of heating for a permanent problem. It also makes it easier to compare whether oil-filled radiators are a backup tool or evidence that the home needs a better main system.
Call us: 07718 059 284 | Email: admin@electromatic.uk
Frequently Asked Questions
Most follow-up questions on heat pump vs oil-filled radiators are really about whether a cheap heater can be a realistic alternative to a full system. According to current GOV.UK guidance, it cannot if the goal is efficient whole-home heating.
How much more efficient is a heat pump than an oil-filled radiator?
GOV.UK says a heat pump can produce around three units of heat for every unit of electricity used, whereas an oil-filled radiator is direct-electric resistance heating.
Are oil-filled radiators ever still useful?
Yes. They can be useful as temporary backup or for occasional localised heating, but they are usually not the best whole-home answer.
Do oil-filled radiators provide hot water too?
No. You still need a separate hot-water system, which is one reason they are not comparable to a whole-home heat-pump setup.
Can I get the BUS grant (subject to eligibility) if I replace oil-filled radiators with a heat pump?
Yes, if the property and installation meet scheme rules. The £7,500 BUS grant (subject to eligibility) is always subject to eligibility.
Which option makes more sense in Surrey and TW homes?
For most mainstream houses, a heat pump makes more sense if the property is suitable. Oil-filled radiators are more often a stopgap than the best long-term route.
The information in this article is for general guidance only and does not constitute financial, legal, or technical advice. Energy savings estimates are based on typical UK household data from the Energy Saving Trust and Ofgem (April 2026 price cap). Actual savings depend on your property type, insulation levels, energy usage patterns, and electricity tariff. The Boiler Upgrade Scheme (BUS) grant of £7,500 is subject to eligibility criteria set by Ofgem — not all properties qualify. Electromatic M&E Ltd operates under MCS certification via an accredited umbrella partner. All installations comply with Building Regulations Part L and MCS standards. E&OE.
Written by Electromatic M&E Ltd — ASHP & Solar installer, London & Surrey (electromatic.uk)
Last updated: April 2026 | Electromatic M&E Ltd, Company No. 13837345
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