Heating Systems Installation in London

Who We Are? 

J SONS & CO. designs and installs heating systems across London and Harrow or all over the UK. In London, gas boilers, electric boilers, air source and ground source heat pumps, underfloor heating, hot water cylinders and full commercial plant-room replacements. 

Our London engineers are Gas Safe registered (commercial and domestic), MCS approved for heat pump installation under the Boiler Upgrade Scheme (BUS), and NICEIC qualified for the electrical work that every heating install requires. 

Types of Heating Systems We Install

Commercial Gas Boilers in London

We install, replace and upgrade commercial gas boiler systems from 30kW to 2MW+ across offices, hotels, schools, care homes, healthcare facilities, restaurants, places of worship and industrial premises. Single boilers, cascade systems, condensing high-efficiency units and full plant-room replacements. Pre-commissioning power-flushing, water treatment to BS EN 7593, and BMS integration are standard inclusions.

Preferred manufacturers: Worcester Bosch Commercial, Vaillant Commercial, Viessmann, Remeha, Ideal Commercial, Hamworthy, Atag, Bosch ZBR.

Domestic Gas Boilers in London

System boilers, combi boilers, heat-only/regular boilers for houses, flats and HMO properties. New installs, like-for-like replacements, and full conversions from G-rated to A-rated condensing systems. Manufacturer warranties up to 12 years on Worcester Bosch, 10 years on Vaillant and Baxi, with an annual service requirement to keep the warranty valid.

Preferred manufacturers: Worcester Bosch, Vaillant, Baxi, Ideal, Viessmann, Glow-worm, Alpha.

Air Source Heat Pumps in London and all over the UK

Air source heat pumps (ASHPs) are the most significant change in domestic and small-commercial heating in twenty years.

In London, ASHP installations are MCS-certified to qualify for the £7,500 Boiler Upgrade Scheme grant. Systems are sized to the property’s heat loss calculation (not to match the old boiler), with low-temperature radiator design or underfloor distribution. We work with Daikin Altherma, Mitsubishi Ecodan, Vaillant aroTHERM, Samsung EHS and Worcester Bosch CDi.

Ground Source Heat Pumps in London

GSHPs use buried ground collectors or boreholes to extract low-grade heat from the ground. Higher capital cost than ASHPs (£18,000–£35,000 typical installed) but better seasonal performance and quieter operation. Best suited to new-build properties or large gardens. Eligible for the BUS grant on the same £7,500 basis.

Underfloor Heating: Wet

Wet underfloor heating runs warm water through PEX or composite pipework laid in screed, suspended timber, or low-profile retrofit boards. Comfortable, even heat distribution, no visible radiators or skirting heaters. Compatible with gas boilers, heat pumps and district heating.

In London, typically run from a gas boiler or heat pump, designed to lower flow temperatures (35–45°C) than radiator systems, which makes it ideal for heat pump pairing.

Underfloor Heating: Electric service in London 

Electric underfloor heating mats laid in tile adhesive or loose-wire systems for irregular spaces. Best for individual rooms and bathrooms where running a wet circuit is impractical. Quick to install, low ceiling-height impact, full thermostat control per room.

In London, it is most often specified in bathroom refurbishments and kitchen extensions.

Hot Water Cylinders and Calorifiers in London

Unvented and vented cylinders, indirect and direct, copper and stainless steel. Sizes from 90L for flats up to 500L+ for commercial buildings and care homes. Twin-coil cylinders for solar thermal or heat pump integration. Pressurised systems certified by G3-qualified engineers. Mains-boost pumps where pressure is inadequate.

Our Installation Process

Every heating project follows the same six-step process regardless of size, a 25kW domestic combi swap or a 1.5MW commercial plant-room replacement.

1. Free site survey. A qualified engineer attends in person. Existing system documented and photographed. Pipework, electrical supply, gas supply, ventilation, and condensate drainage were all assessed.
2. Heat loss calculation. For boiler replacements, an MCS-standard heat loss survey for heat pumps, or a commercial heat load calculation for plant rooms. Systems specified to the actual load, not oversized to inflate the quote.
3. Fixed-price written quote. Itemised: equipment, labour, ancillaries, pipework, electrical works, builder’s work, commissioning, certification, warranty. No hidden costs.
4. Programme, RAMS and approvals. Programme of works, risk assessment and method statement, plus any landlord/freeholder approvals, planning applications, Listed Building Consent  submitted on your behalf.
5. Installation. All work to the manufacturer’s specification and current regulations. Pressure testing, flushing, dosing with corrosion inhibitor, and commissioning to manufacturer-stipulated parameters.
6. Certification and handover. Gas Safe CP12 (London), Building Regulations Part L notification, MCS certificate for heat pumps, electrical certificate, manufacturer warranty registered, O&M pack handed over.

Heating Installation in London

UK Regulatory Framework

• Gas Safe Registration: Any gas work in the UK must be carried out by a Gas Safe registered engineer with the appropriate ACS qualifications (CCN1 + CENWAT for domestic, COCN1 + CIGA1 + CDGA1 for commercial). J SONS & CO. London is Gas Safe registered. Using an unregistered gas fitter is illegal and voids household insurance.
• Building Regulations Part L: Sets minimum efficiency standards for new and replacement heating. Boiler installations must be notified to building control (typically via Gas Safe’s notification system) within 30 days of completion.
• Building Regulations Part J: Combustion and flue requirements.
• Building Regulations Part G: Hot water safety, unvented cylinder G3 qualification.
• MCS (Microgeneration Certification Scheme): Required for heat pump installations claiming the BUS grant. J SONS & CO. is MCS certified.
• Boiler Plus regulations: Combi boilers installed in England must include load compensation, weather compensation, FGHR, or smart controls.

The Boiler Upgrade Scheme (BUS):  £7,500 Grant

The Boiler Upgrade Scheme provides £7,500 toward the installation of an air source heat pump, ground source heat pump or biomass boiler in eligible UK properties. Eligibility requires:

• Property must be in England or Wales
• Must be replacing a fossil fuel system (gas, oil, electric)
• An EPC certificate (less than 10 years old) with no outstanding loft or cavity wall insulation recommendations
• Installation by an MCS-certified contractor (we are)

We handle the grant application as part of the installation. Net cost to client after BUS grant on a typical 8–12kW air source heat pump install: £4,500–£9,500 vs. £12,000–£17,000 without grant.

London Heating Installation Costs

Indicative pricing. Fixed-price quote provided after free site survey. VAT additional.

Why London Heating Demand Is Different

London is the most concentrated commercial gas market in the UK and home to a significant proportion of the country’s listed residential building stock. Heating decisions here are constrained by:

• Listed building consent restricting boiler relocation, flue routing and external plant placement
• Conservation areas with Article 4 directions restricting visible heat pump units
• Leasehold and freeholder consent for any flue or external alterations
• Plant room space constraints in high-density commercial buildings
• Smoke control zones affecting fuel-burning appliance choice
• Winter peak demand is placing real reliability requirements on commercial heating

Boiler failures in February cost businesses far more than boiler maintenance costs in October. Our commercial PPM contracts deliver the response time and the preventative maintenance that prevents the February failure entirely.

Heating System Brands We Install

Boilers (UK): Worcester Bosch, Vaillant, Baxi, Ideal, Viessmann, Remeha, Hamworthy, Atag, Glow-worm, Alpha, Bosch.

Underfloor heating: Uponor, JG Speedfit, Polypipe, Nu-Heat, Warmup (electric), ThermoSphere (electric).

Hot water cylinders: Megaflo, Telford, Joule, Range Tribune, Mixergy, OSO.

Solar thermal: Viessmann Vitosol, Vaillant auroTHERM, Solahart, Apricus.

Pool heating: Calorex, Heatstar, Hayward, Pentair, Therma-Pool.

Sectors We Install Heating For

Houses and flats, HMOs, period and listed buildings, luxury villas, townhouses, apartment buildings, offices, retail units, restaurants, cafés, hotels, boutique hotels, spas, gyms, hammams, leisure centres, schools, nurseries, universities, churches, mosques, temples, healthcare clinics, dental practices, GP surgeries, private hospitals, care homes, sheltered housing, embassies, food production facilities, central kitchens, warehouses (frost protection), workshops and industrial premises.

Why Commercial and Residential Clients Choose J SONS & CO.

Gas Safe in London Every install is fully certified, fully insured, and fully documented.

MCS heat pump certification in London. We handle the £7,500 BUS grant application as part of the installation.

Honest specification. Boilers and heat pumps are sized to the property’s heat loss calculation, not oversized to inflate the quote.

No subcontracting on core trades. Gas, electrical, pipework, controls, all in-house.

Heat pump expertise. ASHPs and GSHPs are now a real share of our London installs and a growing part of  water-heating work. We have the training and the manufacturer accreditations.

Manufacturer warranties up to 12 years. Worcester Bosch 12-year, Vaillant 10-year, Baxi 10-year, when installed by accredited installers like us, which we are.

Single contractor accountability across multi-system projects. Boiler + underfloor + hot water + controls, one quote, one warranty, one point of contact.

Frequently Asked Questions

How long does a boiler replacement take in London?

A like-for-like combi boiler swap takes 1 day in most cases. A full system upgrade with new pipework and controls takes 2–3 days. A boiler conversion from regular to combi typically takes 3–4 days. Commercial boiler replacement varies from 2 days for a single unit swap to 4–8 weeks for a full plant-room replacement.

How much does a new boiler cost in London?

A combi boiler replacement like-for-like is typically £2,200–£3,500 supplied and installed. A full upgrade with power flush and new controls is £3,200–£4,800. System boilers with a cylinder are £2,800–£4,500. Full price tables are in the London Heating Costs section above.

Is it worth installing a heat pump in London?

For most properties with reasonable insulation, yes, particularly with the £7,500 BUS grant. Heat pumps deliver 3–4× the heat output per unit of electricity input compared to direct electric heating, and they qualify for the lower-emissions narrative that commercial tenants and ESG-reporting landlords now expect. Best results come from properties with low-temperature heating distribution (underfloor or oversized radiators).

Can underfloor heating be retrofitted into an existing property?

Yes, in London. Wet retrofit underfloor systems use low-profile boards (15–25mm) that fit over existing floors with minimal floor-height impact. Electric mat systems are even thinner (4–6mm) and ideal for bathrooms and kitchens. The cost is higher than new-build underfloor (which is laid in screed), but it’s a viable retrofit.

Do you handle the BUS grant application?

Yes. For any MCS-eligible heat pump installation in England or Wales, we manage the BUS grant application as part of the project. The grant is paid directly to us as the MCS-certified installer, and we deduct it from the client’s invoice. Net cost to you is the post-grant figure.

Do you work with district cooling and district heating systems?

We connect, commission and service the unit-level heating equipment that sits behind district cooling and district heating interfaces in London high-rise buildings. The district network itself is the responsibility of the utility operator; we work everything from the building interface inward.

Can you install heating in a listed building in London?

Yes. Listed building heating work requires a sympathetic specification, concealed pipework, low-impact radiator placement, sometimes pre-existing radiator positions retained even when not technically optimal, and sometimes Listed Building Consent for any flue or external alteration. We have installed and replaced heating systems in listed properties across central London and the Home Counties.

Request a Heating System Quote

For London projects Phone: +44 20 8050 7969

Email: info@jsonsco.com

Address: Wembley, London, United Kingdom, HA9  Hours: Winter emergency line 24/7 for contract clients.