Boilers and Heating

Boilers and Home Heating: The Full UK Guide

Most homes in the UK are heated the same way they have been for decades: a boiler burning gas, sending hot water to radiators around the house. In the DESNZ Public Attitudes Tracker for Winter 2025, three quarters of people (75%) said they used a gas boiler as their main method of heating the home, and oil boilers accounted for a further 5%¹. Independent guidance from the Centre for Sustainable Energy puts the combined figure even higher, at around 90% of UK homes using gas or oil for heating². That single arrangement, boiler plus radiators, is the default against which every alternative is measured.

It is also the arrangement the country has decided to change. Boilers account for around 60 per cent of all domestic CO2 emissions³, and the Climate Change Committee's Seventh Carbon Budget requires that all new and replacement heating systems become low carbon after 2035, to ensure a fully decarbonised housing stock by 2050⁴. What that means for an ordinary householder is set out across this guide: what each heating type does, what it costs to run, what the rules require, and what each choice leaves a household dependent on.

How UK homes are heated today

The starting point for any heating decision is the shape of the existing stock. Most heating in the UK is supplied by gas⁶, and the official statistics bear this out at every level. The Office for National Statistics publishes two datasets that map the territory: data on heat pumps used in central heating of dwellings in England and Wales⁷, and data on the main fuel type or method of heating used in central heating in England and Wales⁸. Both are maintained by the ONS Housing Analysis team, and together they record how each dwelling is heated and how quickly the balance is shifting.

The picture differs by nation. The Scottish House Condition Survey 2024 found that around 9% of dwellings on the gas grid use an alternative fuel, such as electricity, as their main heating fuel⁹. That figure matters because it shows the gas grid does not dictate the fuel even where it reaches the door: a tenth of connected Scottish homes heat with something else. Off the gas grid, the range widens considerably, as the section on oil and LPG below sets out.

For a household planning ahead, the useful framing is this: the boiler-and-radiators arrangement is the incumbent, the alternatives are growing from a small base, and the official projections all point the same way. The CCC's CB7 Balanced Pathway Scenario estimates approximately half of UK homes being heated by heat pumps¹⁰. The question for most households is not whether the heating landscape changes, but when their own home crosses from the old arrangement to the new one.

Boilers: gas, oil, LPG and biomass

A boiler burns fuel to heat water, which a pump then circulates through radiators or underfloor pipes and, in most homes, through a hot water cylinder or a combi's heat exchanger for taps. The three main types are explained in detail on their own pages: combi boilers, which heat hot water on demand with no cylinder, system boilers, which take their water supply directly from the mains and use a cylinder, and regular boilers, which pair with a cylinder and, usually, a cold water tank in the loft.

The rules that govern boiler installation are set in building regulations. In Wales, each boiler must have a minimum efficiency of 86% for gas and 85% for oil, and the replacement of a gas boiler will probably have to be a condensing boiler unless there is sufficient reason why one cannot be installed⁵. Condensing boilers recover heat from the flue gases that older designs wasted, which is why condensing technology is now the legal default rather than an option. The same regulations state that for a gas boiler, an installer should be Gas Safe Registered, a requirement in force since 1 April 2009⁵.

The official baseline for what a "typical" home looks like is telling. The notional dwelling used in Approved Document L, the building regulations guidance on conserving fuel and power in dwellings, specifies a heating system of a boiler and radiators¹¹. That is the reference case against which new homes and works are assessed: the boiler-and-radiators home is written into the regulations themselves.

Biomass sits at the edge of this group. A biomass boiler burns wood pellets, chips or logs rather than a fossil fuel, and under Scotland's New Build Heat Standard, bioenergy heating systems can be installed in all new homes and buildings, and continue to be used in existing buildings being converted¹². Biomass is the one boiler type in this group that is not being phased out, because the fuel is treated as renewable rather than fossil.

Gas boilers: efficiency, running costs and what they heat

Gas is the default because it is, for now, the cheapest fuel to run. The Expert Advisory Group behind Scotland's Heat Pump Sector Deal reported that in areas on the gas grid, fuel costs for gas boilers are cheaper than for heat pumps, despite the latter's much greater thermal efficiency¹³. A heat pump delivers more heat per unit of energy than a boiler does, but electricity costs more per unit than gas, and that price gap outweighs the efficiency gap. This is the single fact that explains why 75% of households remain on gas¹ despite the direction of policy.

What a gas boiler heats depends on its type. A combi heats hot water on demand; a system or regular boiler heats a hot water cylinder. The efficiency floor is 86% for gas⁵, and real-world efficiency depends on the flow temperature the boiler is set to: lower flow temperatures let the boiler condense properly and extract more of the fuel's heat. Boiler sizing matters too, because an oversized boiler short-cycles, switching on and off, which wastes fuel and wears components.

The dependencies a gas boiler creates are worth stating plainly. The household depends on the gas grid, on a gas supplier for billing, and on the wholesale gas market, which sets the price. A gas boiler cannot run without electricity either: the pump, ignition and controls all need mains power, so a power cut stops the heating. There is no storage of fuel in the home, unlike oil or LPG, so there is no buffer against supply interruption or price spikes beyond what a supplier's tariff offers.

The rules around gas also carry safety obligations. Gas work must be carried out by a Gas Safe Registered installer⁵, and the safety framework around gas appliances, including carbon monoxide, is covered in gas safety in the home and carbon monoxide safety.

Oil and LPG: heating off the gas grid

Many UK homes are not connected to the gas grid, and they use a range of other fuels to heat their homes, including heating oil, liquefied petroleum gas (LPG), solid fuels, mains electricity, and microgeneration¹⁴. The practical differences between oil and LPG are set out in full on the oil boilers and LPG heating pages, but the ownership and cost structures differ in ways that matter to independence.

An oil household owns its tank and buys fuel on the open market, timing purchases against price movements. An LPG household usually does not own the tank: the supplier does, and an ongoing rental charge applies, which ties the household to that supplier's prices. Northern Ireland has the highest concentration of oil-heated homes in the UK, and the NI direct home heating oil support scheme offered a £100 digital pre-paid card to help with the cost of home heating oil¹⁵.

The policy position on off-gas-grid fossil heating has shifted. The UK Government decided to delay the ban on installing oil and LPG boilers, and new coal heating, for off-gas-grid homes from 2026 to 2035¹⁶. That delay moved the deadline for off-grid homes to the same date as the wider 2035 phase-out, so off-grid households now face one deadline rather than an earlier one.

Support for switching is available in the meantime. Homes heated by oil or LPG may be eligible for a £9,000 government grant towards the cost of installing a heat pump until March 2027¹⁷. The off-grid household's independence picture is mixed: oil and LPG both give the household stored fuel on site, a real buffer against grid events, but both tie the household to delivered fuel prices and, in the LPG case, to the tank owner.

Electric heating using boilers and storage heaters

Electric heating divides into two families: direct-acting appliances that heat when switched on, and storage systems that charge when electricity is cheap and release heat later. An electric boiler is direct-acting: it heats water for radiators exactly like a gas boiler, but using resistance heating, at near-100% efficiency at the point of use. The efficiency is not the problem; the price of electricity is. Independent guidance puts an electric boiler on Economy 7 at £2,690 a year for an average flat or small home².

Storage heaters work the other way round, charging on off-peak electricity overnight and releasing heat through the day. Scotland's proposed Heat in Buildings Bill lists the clean heating systems it would require as heat pumps, electric storage heaters, heat networks, wet electric heating and other direct electric heating technologies¹⁶. Modern, efficient electric storage heaters can perform the same role as a heat pump in the bill's framework, as can wet electric heating and other direct electric technologies¹⁶.

The running-cost hierarchy among electric options is clear from the independent figures. Heat pumps cost around £800 to £1,050 a year to run, making them one of the cheapest electric heating options². Heat batteries, which store heat on off-peak rates, cost around £1,770 a year for an average home on Economy 7 or an off-peak tariff². Direct electric heating, including panel heaters and infrared, sits above that. The differences are driven by when electricity is bought and how many times each unit of electricity is converted to heat.

The tariff side of this is covered in Economy 7 and time-of-use tariffs, and the running costs in electric heating running costs. The independence picture for electric heating is the inverse of gas: the household depends entirely on the electricity grid and its supplier, with no on-site fuel, but pairs naturally with self-generated electricity, which no boiler can do.

Radiant panel heating and typical prices

Infrared heating works differently from every other system on this page. Instead of heating air and circulating it, infrared panels emit radiant heat that warms people and surfaces directly, the way sunshine warms a wall. The panels themselves are thin, wall- or ceiling-mounted, and have no moving parts. Infrared heating is explained in depth on its own page.

The costs are documented by the Centre for Sustainable Energy. Infrared panels cost £100 to £200 per heater to install, and their running costs are similar to panel heaters: around £1,080 a year for a flat². That places infrared among the more expensive electric options to run, comparable to other direct-acting electric heating rather than to heat pumps or storage systems.

What infrared offers is control at the level of the room and the hour. Each panel is individually switched, so a household heats only the rooms in use, which the annual figure does not capture: the £1,080 comparison assumes the same whole-home heating pattern as other systems. What infrared does not offer is storage or cheap-tariff leverage, because it uses electricity at the moment heat is wanted.

The independence position is the same as all direct electric heating: total dependence on the grid and the supplier, offset by the possibility of pairing with solar generation, since panels draw power in daylight hours when a home's own solar output is highest.

Wet versus dry underfloor heating systems

Underfloor heating comes in two forms. Wet, or water-based, systems have a series of pipes laid underneath the floor, connected to the heating source, which sends warm water through the pipes¹⁸. Dry systems use electric heating cables or mats laid in the floor construction, heating directly rather than through circulated water.

The wet form has a property that matters more each year. With a larger surface area than radiators, a wet underfloor system can heat a home at lower boiler or heat pump flow temperatures than radiators, saving money on energy bills¹⁸. The same source notes that wet underfloor heating is easy to combine with low carbon heating systems like heat pumps¹⁸. Because a heat pump's efficiency rises as the temperature it must deliver falls, underfloor heating and heat pumps are a natural pairing: the floor does with a large area and modest temperature what a radiator does with a small area and high temperature.

The trade-offs are practical rather than financial. Wet underfloor heating is installed within the floor structure, so it suits new builds, extensions and major renovations far better than retrofit into an existing finished floor. It also responds slowly: a large concrete floor takes hours to warm and cool, which suits homes heated steadily rather than in short bursts. The full comparison of wet and electric systems, including the electric form's suitability for single rooms, is on the underfloor heating page.

Radiators: sizing, bleeding and lower flow temperatures

Radiators are the emitters in most UK systems, and two household-level questions dominate: why a radiator heats unevenly, and what happens to radiators if the home moves to low-temperature heating.

The uneven-heating question has two distinct answers depending on which half is cold. If a radiator is hot at the top and cold at the bottom, the problem might be sludge or debris in the system, which can be flushed out by a professional¹⁹. Independent guidance is firmer still: radiators that are hot at the top and cold at the bottom need a power flush²⁰. If the top stays cold while the bottom warms up, trapped air is the likely cause¹⁹, released by bleeding the radiator. The bleeding process is described step by step in how to bleed a radiator.

The low-temperature question has a hard number attached. Radiators for low temperature heating systems typically require to be around 2.5 times larger than a conventional radiator²¹. A heat pump delivers water cooler than a boiler does, and a radiator gives out less heat at lower temperatures, so it needs more area to give out the same heat. This does not mean every radiator must be replaced when a heat pump is installed, but it does mean each room's emitter has to be checked against the new flow temperature, with larger radiators or underfloor heating used where the existing ones fall short.

The compatibility question is answered at the national level by the Parliamentary Office of Science and Technology: heat pumps are technically suitable for most UK homes if installed appropriately²². The emitter survey, room by room, is where that suitability is tested in practice.

Running costs, controls and servicing

Controls decide when heat is made and where it goes. Heating controls, thermostats and TRVs cover the full range, from programmers and room thermostats to thermostatic radiator valves and weather compensation. The Boiler Plus standard, covered in Boiler Plus, sets the minimum control requirements for boiler installations in England.

Servicing has a legal dimension in rented homes. In rented accommodation, the landlord is responsible for servicing boilers and appliances annually and must provide an up-to-date gas safety record, which is a legal requirement²³. In owner-occupied homes, annual servicing is a matter for the householder, and it is normally a condition of the manufacturer's warranty, covered in boiler warranties and boiler servicing and maintenance.

Everyday checks fall to the householder in every tenure. Boiler pressure is displayed on a dial, a hydraulic pressure gauge, or a digital display on modern combi boilers²⁴, and the normal range and topping-up procedure are covered in boiler pressure. A boiler housed in a cupboard should be fitted with at least 60 mm clearance²⁰, which keeps air moving and leaves room for an engineer to work. The common faults and what the display codes mean are in boiler faults and fault codes.

Running costs by fuel, and how they compare, are set out in home heating running costs. The headline figures from independent guidance are that heat pumps cost around £800 to £1,050 a year to run, making them one of the cheapest electric heating options, while gas remains cheaper still on the gas grid¹³.

UK suppliers and their product lines

The UK boiler market is served by a small number of manufacturers whose ranges are documented on this site's brand pages, including Vaillant, Worcester Bosch, Ideal, Baxi, Viessmann and Intergas, with oil specialists such as Grant and Warmflow. The brand comparisons, including Worcester Bosch vs Vaillant and Grant vs Worcester oil boilers, are on their own pages.

One maker's range illustrates the shape of the oil market. Warmflow's Professional oil boiler range is available in both internal and external models, ranging in heat outputs from 15 to 33 kW, with an extended warranty available subject to terms and conditions²⁵. The range spans a typical family home's needs from a small semi to a large detached house, and the external models are sited outside the building, which removes the flue and clearance constraints of an indoor cupboard installation. The Warmflow range is compared with Grant's in Warmflow vs Grant oil boilers.

The electric side of the market is similarly concentrated, with Dimplex dominant in storage heating, Heatrae Sadia in electric flow boilers, and specialist makers such as tepeo in heat batteries. Product-level pages, including the Dimplex Quantum storage heater and the tepeo Zero Emission Boiler, carry the specifications and warranty terms for each model.

How long they last, replacing them and your rights

A boiler's working life is around 15 years³. That figure sets the rhythm of household heating decisions: a boiler bought today will be replaced roughly twice before the 2050 decarbonisation deadline, and the second of those replacements will fall after 2035, when all new and replacement heating systems must be low carbon⁴. The practical question for a household replacing a boiler in the late 2020s is whether that boiler will see out its working life or be superseded early.

Replacement costs and the factors that drive them are covered in new boiler cost and boiler installation. The VAT position depends on circumstances: heating equipment and connection of gas supply carry a reduced 5% rate to the extent they are grant-funded by certain funders to people aged over 60 or in receipt of certain benefits, and this covers gas-fired and oil-fired boilers, electric storage heaters, radiators, and the installation, repair and maintenance of central heating systems and renewable source heating systems²⁶.

Consumer protection for heating is being reformed. A consultation on reforming consumer protection for home upgrade schemes notes that the new Home Energy Advice service will help homeowners, landlords and tenants find tailored, impartial and trusted advice on how to heat their homes and make them more energy efficient²⁷. Heat network consumers can access the Energy Ombudsman's free and independent dispute resolution service²⁸. The government's Heat Pump Ready Programme includes work to improve the lifetime consumer experience of heat pumps²⁹.

Warranty terms are covered in boiler warranties, and the ownership history of the brands behind UK boilers, including which companies now stand behind familiar names, is in Potterton, Baxi and the brands behind UK boilers.

The phase-out of fossil fuel boilers

The direction of policy is set at UK level and implemented differently in each nation. The Climate Change Committee's Seventh Carbon Budget requires that all new and replacement heating systems become low carbon after 2035, to ensure a fully decarbonised housing stock by 2050⁴. The UK Government had already delayed the ban on installing oil and LPG boilers, and new coal heating, for off-gas-grid homes from 2026 to 2035¹⁶, aligning the off-grid deadline with the general one.

The scale of the change is projected in official analysis. The Climate Change Committee projects that, to reach net zero, domestic heat pumps will be needed in at least half, but likely closer to 80%, of homes by 2050²². The CCC's CB7 Balanced Pathway Scenario estimates approximately half of UK homes being heated by heat pumps¹⁰. The Parliamentary Office of Science and Technology adds the reassurance that heat pumps are technically suitable for most UK homes if installed appropriately²², and the government's clean heat campaign states that studies suggest 90% of UK homes already have enough insulation to run a heat pump¹⁷.

Scotland goes further than the rest of the UK in draft law. The proposed Heat in Buildings Bill would require clean heating systems, listed as heat pumps, electric storage heaters, heat networks, wet electric heating and other direct electric heating technologies¹⁶. New build is already handled: under the New Build Heat Standard, bioenergy heating systems can be installed in all new homes and buildings¹², while fossil fuel boilers cannot.

The routes by which home heating decarbonises nationally are expected to be three: heat pumps, hydrogen and/or heat networks, alongside energy efficiency through insulation upgrades³⁰. For an individual household, the realistic route today is a heat pump, electric heating of some form, or a heat network where one exists. The gas boiler ban and Future Homes Standard pages carry the detail, and heat pumps compared with boilers sets the two side by side.

Heating choices and your home's energy self sufficiency

Every heating choice is also a dependency choice, and the dependencies differ sharply.

• Gas boiler: depends on the gas grid, a gas supplier, the wholesale gas market, and mains electricity for pump and controls. No fuel stored on site.
• Oil boiler: depends on delivered fuel and its price, but the household owns the tank and holds a stock of fuel on site.
• LPG boiler: depends on the supplier that owns the tank, with an ongoing rental charge, and on delivered fuel prices.
• Direct electric heating: depends entirely on the electricity grid and supplier, with no on-site storage, but pairs with solar generation.
• Storage heating and heat batteries: depend on the grid and on an off-peak tariff, storing cheap electricity as heat.
• Heat pump: depends on the grid and supplier for electricity, but uses far less of it per unit of heat than any resistance appliance.
• Biomass: depends on delivered fuel, but the fuel is renewable and the household holds it on site.

The fuel-cost reality check is the Expert Advisory Group's finding that in areas on the gas grid, fuel costs for gas boilers are cheaper than for heat pumps, despite the latter's much greater thermal efficiency¹³. Independence from the gas grid currently costs more in running costs, not less, unless a household generates its own electricity.

Advice is free and nation-specific. Home Energy Scotland provides free, independent advice on energy efficiency and low and zero emission heating, and acts as a referral scheme for the Warmer Homes Scotland scheme³¹; it can provide specialist advice tailored to the needs of the household on how to operate heating systems effectively³². Northern Ireland's Energy Advice service directs homeowners to independent advice on solar panels, heat pumps, and other energy efficiency measures³³. The government's Check if a heat pump could be suitable for you service takes the nation, the heating system type and the number of bedrooms as its inputs³⁴, and the Warm Homes: Social Housing Fund is installing energy efficiency upgrades and low-carbon heating measures in English social housing¹⁰.

The honest summary is that no heating choice removes dependence entirely. A gas boiler ties a home to gas; a heat pump ties it to electricity; a heat battery ties it to an off-peak tariff; biomass ties it to fuel deliveries. What differs is how many intermediaries stand between the household and warmth, whether any fuel or heat is held on site, and whether the system can use electricity the household generates itself. Those three questions, asked of any heating system, are the test of how independent it really is.