My oil boiler needs work. Should I repair it, replace it or switch to a heat pump?
When the heating stopped working at a home in Builth Wells, our engineer found a split hose connected to the air pressure switch on the homeowner’s Navien LCB700 oil boiler. We replaced the switch and hose, tested and recommissioned the boiler, and checked that the heating was working again. The homeowner could carry on using the system they already had.
If your own oil boiler needs attention this winter, SwiftHeat UK can assess and repair it or replace it with a new oil boiler, or assess your home for an air source heat pump. You can come to us for the assessment alone. If you decide to switch, we can take the project from that first survey through design, installation, commissioning and aftercare.
Why oil-heated homes in Wales are weighing up their options
In the 2021 Census, 27.7% of Powys households used oil as their only central heating fuel. For homeowners across the county, the choice of what comes after an oil boiler is a practical question, especially when repair bills start to mount.
There’s also a reason to explore a heat pump this winter. Eligible homes in England and Wales that are off the mains gas grid and replace oil or LPG heating with an air-to-water heat pump can currently receive £9,000 towards installation. Ofgem lists the enhanced rate as available until 31 March 2027. Between July and September 2026, the scheme received 8,107 applications for the higher grant, around 32% of all applications in those three months.
When is it worth repairing or replacing an oil boiler?
The Builth Wells repair shows why we start with a diagnosis. If a boiler has otherwise been dependable and the fault can be repaired, that may be all your home needs. If you’ve had several call-outs, bring the invoices. Seeing whether the same problem keeps returning or several different components are wearing out helps us give you a more informed recommendation.
If replacement makes sense and you want to stay with oil, SwiftHeat UK can supply and install a new oil boiler. We assess your heating and hot-water needs and check the condition of the tank, oil supply line, flue and controls. Your quotation should make clear which parts of the existing installation can stay and what other work is needed. Explore SwiftHeat’s oil boiler repair and replacement services.
What does a SwiftHeat air source heat pump assessment tell me?
A useful assessment should answer a question you can picture on a cold January morning: will my living room stay warm with the radiator I already have?
We look at how much heat each room loses and whether its radiator or underfloor heating can deliver enough warmth at the proposed water temperature. We also assess the pipework, controls, electrical requirements and outdoor unit position. If your oil combi currently provides hot water on demand, we’ll discuss where a cylinder could fit and how much hot water your household needs at its busiest.
You can use those findings to decide whether to proceed. If you choose a heat pump, SwiftHeat UK can coordinate and deliver the complete installation. We work with an MCS-certified partner on the formal system design, certification and any eligible grant application. Our team carries out the agreed installation and system upgrades, tests and commissions the heating, and shows you how to use the controls. Explore SwiftHeat’s air source heat pump assessment and installation services.
What might each option cost to run?
Start with the delivered price on your oil invoice and the unit rate on your electricity bill. Bring 12 months of oil delivery records to the assessment. If you know how full the tank was at the beginning and end of that period, we can estimate how much fuel you actually used.
Both columns below cover the same 12,000 kWh of useful heat a year, using a rounded 10 kWh per litre of oil. The boiler efficiencies and heat pump performance stay the same. Only the energy prices change.
| Heating option | Lower oil priceOil 70p/litre Electricity 25p/kWh | 8 Nov 2026 snapshotOil 110.36p/litre Electricity 26.32p/kWh |
|---|---|---|
| Keep the existing oil boiler80% efficiency · 1,500 litres/year | £1,050 | £1,655 |
| Fit a new oil boiler90% efficiency · about 1,333 litres/year | £933 | £1,471 |
| Fit an air source heat pump (ASHP)Seasonal performance factor 3.0 · 4,000 kWh/year | £1,000 | £1,053 |
| ASHP compared with a new oil boiler at the rates above | £67 more | £419 less |
| What if the ASHP averages 20p/kWh?Same heat demand and seasonal performance | £800 a yearAt 70p/litre for oil, that’s £133 less than a new oil boiler and £250 less than keeping the existing boiler. | |
November price inputs come from Fueltool’s UK supplier average for a 1,000-litre kerosene order on 8 November (including 5% VAT) and Ofgem’s average single-rate electricity price for customers paying by Direct Debit in Great Britain for October to December 2026. The snapshot shows a full year at those unit rates. Actual local quotes and prices over a year will vary. Totals and differences are rounded separately to the nearest pound.
At the November rates, the ASHP costs about £603 less a year in energy than keeping the existing oil boiler and £419 less than fitting a new one. At the lower oil price, the new oil boiler has the lowest fuel cost. For a home with electricity at 26.32p/kWh, the heat pump and the 90%-efficient oil boiler break even at about 79p per litre of oil, assuming the heat pump delivers three units of heat per unit of electricity over the year.
An assessment should estimate the seasonal performance your home can achieve. At a seasonal performance factor of 2.8, the same heat pump would use about 4,286 kWh and cost £1,128 at the November electricity rate. At a factor of 3.0 and an effective electricity rate of 20p/kWh, it would cost £800. For a time-of-use tariff, use the average rate paid across all the hours the pump runs.
These figures cover fuel and electricity for heating. Compare installation, grants, servicing and repairs separately, and account for any change in standing charges when comparing tariffs.
To arrange an oil boiler assessment, request a replacement quotation or book an air source heat pump assessment, call SwiftHeat UK on 0800 043 3464 or message us on WhatsApp. Tell us your postcode, which boiler you have and what’s prompted you to get in touch. If you’re still deciding, that’s exactly where the assessment begins.
Assess First. Recommend Second.