Commercial heat pump installers replacing ageing gas and oil heating across the UK
As commercial heat pump installers, our entire job is the part most quotes skate over: taking a real building off ageing gas or oil heating and onto a low-carbon system that actually delivers the running cost and carbon figures it was sold on. Heat accounts for roughly a third of UK carbon emissions, and for most commercial buildings the gas boiler is the single largest source. We replace that boiler with a commercial heat pump, air-source (ASHP) or ground-source (GSHP), that moves heat rather than burns fuel, delivering three to four units of heat for every unit of electricity. For a facilities, estates or energy manager staring at a boiler nearing failure and a fixed shutdown window, the delivery matters as much as the technology. We design, install and commission systems for offices, care homes, schools, hotels, leisure centres and light industrial sites, and we frame every project around the building in front of us rather than the product we would prefer to sell.
Why commercial buildings are switching to heat pumps
Three pressures push the decision. The first is running cost: gas prices remain volatile and the Climate Change Levy adds to the bill, so heating budgets are unpredictable year to year, while a well-designed heat pump with a good SCOP offsets most of the unit-price gap between electricity and gas and improves further as gas carbon levies rise and the grid decarbonises. The second is carbon: a heat pump removes on-site combustion entirely, with emissions coming only from grid electricity, which keeps falling, so the carbon saving improves every year the system runs, useful evidence for net-zero and Scope 1 and 2 reporting. The third is compliance and asset pressure, ageing boiler plant nearing failure, landlord MEES and EPC obligations, and net-zero commitments with no clear funding route. Replacing a fossil boiler at end of life is the moment the economics line up, and getting ahead of that failure rather than reacting to it is exactly where a specialist installer earns its place.
How we size and design systems
We never size from floor area. Sizing comes from a proper heat-loss survey and at least twelve months of your gas or oil consumption, because the shape of your demand, a care home running flat out all year versus a school dark through the holidays, changes the right answer completely. The cardinal rule we design to is simple: lower the flow temperature to lift the SCOP, every degree shed improves the efficiency you live with for two decades, which is why we design for 45 to 55C wherever the emitters allow and survey those emitters before quoting. Air-source is the workhorse, no ground works, fastest and least disruptive, landing between 40 and 500 kW thermal at an SCOP typically 3.0 to 4.0. Ground-source draws on stable ground temperature for an SCOP often above 4.0 year-round plus low-cost summer cooling, at higher capital and longer lead time, and earns its premium on year-round buildings. We specify to BS EN 14825 (SCOP) and BS EN 14511 (rated COP) so the performance we promise is directly comparable to any other compliant supplier. Where high-temperature emitters make a full conversion costly, our hybrid boiler-replacement retrofit sizes the heat pump for 70 to 90% of annual load with a peaking boiler for the coldest days.
Costs, payback and tax relief
A commercial air-source project typically runs £60,000 to £600,000 with a simple payback around 8 years; ground-source £150,000 to £2,000,000 or more with payback nearer 11 years reflecting the drilling; a hybrid retrofit £70,000 to £500,000 with the quickest payback, around 7 years, because the heat pump is smaller and the emitters often stay. The tax treatment is where the largest saving is found. As heat pumps count as plant and machinery, a corporation-tax-paying company can use full expensing, an uncapped 100% first-year deduction that became permanent in April 2026 and returns up to 25p of tax for every pound spent at the 25% rate. For unincorporated businesses the equivalent is the Annual Investment Allowance, relieving up to one million pounds of qualifying spend at 100%. Some wiring and ancillary works sit outside full expensing but generally still qualify for the AIA, and we always advise clients to verify the precise treatment with their accountant. Our cost guide works the numbers through for different building types.
Funding routes
The funding conversation has one clearing-the-air moment: the £7,500 Boiler Upgrade Scheme is domestic-only and does not apply to your building. We say that plainly because so many competitors leave it vague. The real commercial routes depend on who you are. Public-sector bodies, NHS trusts, schools, colleges, universities, local authorities and emergency services, should look to the Public Sector Decarbonisation Scheme administered by Salix, which funds the cost over and above a like-for-like fossil replacement through competitive windows. Eligible industrial sites and data centres can access the Industrial Energy Transformation Fund for fuel-switching to industrial heat pumps and waste-heat recovery. Multi-building campuses, councils and large mixed-use developments may fit the Green Heat Network Fund, which covers up to 50% of eligible costs. And any taxpaying business can stack full expensing or the Annual Investment Allowance on top. As installers we map which of these you genuinely qualify for and build the application around the design rather than bolting a grant on as an afterthought. The full picture sits on our grants and funding page.
Compliance and sector considerations
A serious installer handles the compliance load by default. Systems up to 45 kWth need MCS certification (or a recognised commercial equivalent) and MCS 025 installer competency to access most grant routes; above 45 kWth we design to CIBSE and BSRIA standards with BS EN 14511 and 14825 performance ratings. The point that catches most projects out is noise: many commercial air-source installs fall under permitted development but are subject to siting and noise limits, so a BS 4142 acoustic assessment is commonly required to show the external units will not disturb neighbours, and listed buildings and conservation areas need consent. All refrigerant work is carried out by F-Gas certified engineers under the UK F-Gas Regulation, and modern units increasingly use lower-GWP refrigerants such as R32, with natural refrigerants (R290 propane, CO2, ammonia) for high-temperature duties carrying their own DSEAR and ATEX siting requirements. Where a gas boiler is retained in a hybrid design, Gas Safe is in scope too. The other early check is electrical: a large heat pump adds meaningful load, so we confirm available supply capacity with your DNO early, because a supply upgrade can be the longest-lead item in the whole job.
How we approach the project
Our method is built to kill the over-promised-quote problem at the root. We pull your half-hourly meter data and at least twelve months of consumption, run a heat-loss survey, and model running cost and carbon from your actual numbers at current and forecast prices, not optimistic estimates. We survey your emitters and pipework so you only pay for the upgrades the flow temperature genuinely requires, never a needless strip-out, and we model air-source and ground-source side by side so you see the whole-life cost of each before deciding. We check plant area, siting and acoustics, and where the supply needs uprating we submit the DNO and any G99 paperwork early to start the clock. We plan the changeover around your operating calendar, typically spring or autumn rather than a peak-heat week, and can keep the existing boiler live through commissioning so you are never without heat. You then receive a fixed-price proposal with the full model attached, which you are welcome to stress-test or take for a second opinion. We would rather lose a job to honest maths than win it on a number we cannot stand behind.
An illustrative example
As an illustrative composite based on the kind of work commercial heat pump installers carry out, and not a real named client: a 70-bed care home running a pair of ageing gas boilers near failure, with year-round heating and hot water and rising bills, had a 180 kW cascaded air-source system installed across six modular units, with selective emitter upgrades and the existing boiler retained for peak backup. At an SCOP of around 3.6 it delivered roughly 360,000 kWh of heat a year, cutting on-site combustion by about 85% and saving in the region of 55 tonnes of CO2. The work was scheduled in autumn around the operating calendar with the old boilers kept live through commissioning so the home was never without heat, and full expensing delivered first-year tax relief on the qualifying cost. The figures are illustrative and depend entirely on your building, heat load, emitters and tariff. If you would like the same modelling done for your site, see the cost guide, the funding routes, our commercial heat pump FAQs, or request a feasibility study from your meter data.
