Heat Pumps, Bills & Comfort: What London Renters Must Know

With the UK pushing for 600,000 heat‑pump installs a year by 2028 and tighter energy‑efficiency rules on the horizon, heat pumps are increasingly appearing in London flats — especially where landlords must meet rising EPC expectations. This guide explains what renters should check now: running costs, noise and external‑unit space, warranties and maintenance, and what to insist on in your tenancy so you don’t face cold surprises or rising bills in 2026.

Quick summary

  • Air‑source heat pumps (ASHP) and ground‑source heat pumps (GSHP) work differently from gas boilers and often run at lower flow temperatures — that affects comfort and radiator sizing.
  • Heat pumps can lower bills and carbon, but savings depend on building fabric, controls, correct sizing and electricity tariffs.
  • Landlords are being pushed by policy and local retrofit funding to upgrade. Renters should check paperwork, servicing history, installer accreditation and ask for tenancy clauses that protect them from unexpected costs or poor performance.

Why heat pumps are appearing in London flats

The UK’s Heat and Buildings Strategy (2021) set out ambitions for a major scale‑up of heat pumps (an eventual target of around 600,000 installations per year by 2028). At the same time, government consultations and proposed changes to the Minimum Energy Efficiency Standards (MEES) are encouraging landlords to get properties to higher EPC bands (EPC C increasingly framed as the long‑term target for private rented homes). That combination — policy pressure plus local retrofit funding streams — is driving landlords and managing agents to retrofit flats, sometimes replacing gas boilers with heat pumps.

In London, central government funding (schemes such as ECO, Home Upgrade Grant (HUG) and Local Authority Delivery (LAD)) and borough retrofit initiatives can make upgrades more likely — though availability varies by borough and household income. Check your borough’s housing or sustainability pages for the latest local schemes and eligibility criteria.

How heat pumps work (briefly) and why it matters for renters

  • Air‑source heat pumps extract heat from outside air and move it indoors; ground‑source pumps draw heat from the ground. Both use electricity to run compressors and pumps.
  • Efficiency is expressed as COP (coefficient of performance). Typical modern ASHPs achieve COPs around 3–4 (i.e., 1 kWh of electricity may deliver 3–4 kWh of heat under favourable conditions). GSHPs can be slightly more efficient but are more intrusive to install.
  • Because heat pumps operate at lower water temperatures than gas boilers, they often need larger radiators or underfloor heating to deliver the same comfort.

What renters need to know: a correctly designed and installed heat‑pump system can be comfortable and cheaper to run than an old inefficient gas boiler; a poorly designed one can leave flat cold or cost more.

Running costs: how to estimate and what to ask for

Running costs depend on three things: how efficient the heat pump is (COP), the electricity tariff you’re on, and how well insulated the flat is.

Simple calculation (example):

  • Assumptions: annual heat requirement = 8,000 kWh of heat (typical small/medium London flat); heat pump COP = 3.5; electricity price = £0.30/kWh.
  • Electricity used for heating = 8,000 kWh ÷ 3.5 = 2,286 kWh.
  • Annual heating cost = 2,286 kWh × £0.30 = £686.

Compare to a gas boiler (90% efficient) with gas at £0.10/kWh:

  • Gas needed = 8,000 kWh ÷ 0.9 ≈ 8,889 kWh.
  • Heating cost = 8,889 × £0.10 = £889.

This simplified example shows a potential saving, but real life varies hugely. If electricity price is much higher relative to gas, or if the COP is lower in cold weather, heat‑pump costs can be higher. The takeaways:

  • Ask the landlord or installer for an estimated annual heating electricity use and the COP used for that calculation.
  • Request recent energy bills for the flat (last 12 months) and, if available, the heating system’s consumption figures separately.
  • Ask if a dedicated submeter or smart meter is fitted to isolate heating electricity from other uses — that helps avoid disputes and allows you to shop for the right tariff.

Practical tip: if the landlord supplies electricity for heat (rather than your tenancy being separately metered), clarify in writing how bills are calculated and whether the landlord will move the property onto a heat‑friendly tariff.

Noise, external unit space and building restrictions

  • Outdoor units (for ASHP) make continuous noise when running. Typical sound levels for modern units are around 40–55 dB(A) at 1 metre — roughly comparable to background city noise but potentially audible in neighbouring flats or gardens.
  • Placement matters: balconies, courtyard spaces or roofs may be used for outdoor units, but access and ventilation are needed. In flats, shared access areas may require landlord or management company approval.
  • Conservation areas, listed buildings and some leaseholds may require planning permission or landlord approval for external units; for blocks with communal façades or limited roof space, installing a unit could be complicated.

What to check before you sign:

  • Ask where the external unit sits. Visit the location and listen (if possible) during a heating cycle.
  • Check if other flats share the same unit or ducting (common in heat‑networked systems) — shared systems can complicate responsibility and billing.
  • Ask for a noise report or manufacturer spec sheet showing dB(A) at standard distances.
  • Confirm who is responsible if neighbours complain (landlord or freeholder usually handles planning and complaints for communal areas).

Warranties, installer accreditation and servicing

  • Insist on seeing the installation certificate and manufacturer warranty (many heat pumps carry 5–10 year warranties, sometimes with extended options if annual servicing is followed).
  • Make sure the installer is accredited — look for MCS (Microgeneration Certification Scheme) accreditation or PAS 2035/2030 compliance for retrofit projects. These certifications protect quality and access to some grants.
  • Heat pumps require regular servicing (often annual) to maintain efficiency and keep warranties valid.

As a renter you should ask for:

  • Copies of the MCS certificate and any commissioning paperwork.
  • A clear service schedule with named contacts and budget responsibility (i.e., landlord covers annual service and repairs, tenant covers minor filter cleaning if agreed).
  • Manufacturer contact details and the warranty start date.

Practical example: an ASHP with a 7‑year parts warranty may be voided if not serviced annually by an accredited engineer. Get the service dates in writing and a clause in the tenancy confirming landlord responsibility.

Health, ventilation and comfort considerations

  • Heat pumps produce lower temperature water than gas boilers. If radiators are unchanged and undersized, a flat can feel cooler even with a functioning heat pump. Landlords should upgrade radiators or offer alternative heating solutions.
  • Hot water: some heat‑pump systems use thermal stores or larger cylinders. Ensure the hot water capacity suits your household — ask for velocity/volume figures or recent hot water usage tests.
  • Legionella risk: if there is a storage cylinder, landlords must follow normal hot‑water safety protocols (maintain temperatures or use other controls). This remains a landlord responsibility.

Practical checks at viewing:

  • Turn on all radiators and hot water to feel how quickly the flat warms up.
  • Ask for temperature readings and how long it takes to reach comfort levels in winter.
  • Check for ventilation in bathrooms and kitchens — heat pumps work alongside improved insulation; you don’t want damp or condensation issues.

Who pays for electricity and how to avoid disputes

  • If the property’s electricity is billed to the tenant, heating will show up on electricity bills — so the tariff matters. In multiflat blocks with communal distribution, heat may be billed proportionally by the freeholder/management company.
  • Ask whether the landlord will provide a heat‑friendly tariff or a dedicated electricity meter for heating.
  • Consider negotiating a cap, rebate or rent adjustment for a trial period if the heat pump is newly installed and the landlord cannot provide reliable usage estimates.

Suggested clause to propose in a tenancy (short form):

  • “Landlord agrees to provide annual servicing for the heating system and to supply the Tenant with the installation certificate, commissioning report and current manufacturer warranty at the start of the tenancy. Any faults affecting heating or hot water will be remedied by the Landlord within 7 working days (or sooner if temperature below 18°C).”

For stronger protection, ask for a guaranteed minimum indoor temperature or a compensation formula for substandard performance.

What to insist on in the tenancy and negotiation scripts

  1. At viewings — quick script to agents/landlords:
  • “Can you confirm if the flat uses a heat pump or gas boiler? Can I see the EPC and any recent heating bills or service records?”
  1. After offer — email template to request paperwork and responsibilities:
  • “Thanks. Before we exchange I’d like copies of the heat pump installation certificate, MCS commissioning report, manufacturer warranty and last two service invoices. Please also confirm who pays for heating electricity and the landlord’s timescale for annual servicing.”
  1. Insert into tenancy agreement (negotiation language):
  • “Landlord to maintain the heat pump, provide annual service receipts and ensure the system meets relevant building regulations and MCS commissioning. Landlord to be responsible for repair and replacement costs for 12 months following tenancy start, unless damage caused by Tenant.”
  1. If heating is newly installed and there’s uncertainty around bills — trial clause:
  • “For the first heating season the Landlord agrees to reimburse any net increase in heating costs above the property’s average for the previous 12 months, subject to provision of bills and an independent assessment if requested.”

These scripts are pragmatic starting points — tailor the timing (e.g., extension for the landlord to provide paperwork before tenancy start) and get any promises into writing.

Checklists: what to check at viewing and before signing

At viewing:

  • Is the system a heat pump (ASHP/GSHP) or a heat network? Where is the external unit?
  • Can I see the EPC and the current band? Is there an energy performance action plan?
  • Turn on heating and hot water; note how long it takes to heat and how rooms feel.
  • Check radiators and controls — are they thermostatic? Is there programmable scheduling and a room thermostat?
  • Listen near the external unit for noise (visit during operation if possible).

Before signing:

  • Request installation certificates, MCS/commissioning paperwork and manufacturer warranty.
  • Ask for last 12 months of energy bills or system consumption data.
  • Agree in writing who pays for heating electricity, service schedule and response times for repairs.
  • Check planning permission/leaseholder consent for the external unit where relevant.

Borough grants, national schemes and where to look for support

  • Central government schemes such as ECO (Energy Company Obligation) and HUG/LAD have funded some retrofit and heat‑pump installs; eligibility is usually means‑tested or targeted at low income/hard‑to‑treat homes.
  • The Greater London Authority and some local boroughs run retrofit advice and occasionally grant or loan programmes for landlords. Availability is patchy — check your borough website or email the housing team for current offers.
  • If you’re on benefits or in a low‑income household, ask the council or your landlord whether ECO funding or other grant routes were used for the installation (this can affect ongoing obligations).

Practical action: search for your borough name + “heat pump grant” or “retrofit grants” and contact the council housing or sustainability team for the most current programmes.

If things go wrong: repairs, cold homes and disputes

  • Landlords must provide working heating at the start of a tenancy and keep the property in repair during the tenancy (Landlord and Tenant Act 1985 and HHSRS standards apply). If heating fails, report it in writing and keep copies.
  • If the landlord delays repairs, use the formal reporting process (write to the landlord/agent, request a timescale, and lodge a complaint with the managing agent if applicable). For urgent failure in winter, contacts include the local council’s environmental health team.
  • If you believe the heating is insufficient because the system was incorrectly designed, request an independent survey. In some cases the landlord may be required to upgrade radiators or insulation to meet habitability standards.

Final practical tips

  • Don’t accept verbal assurances — get installation certificates, warranties and servicing commitments in writing.
  • Ask for a submeter or smart meter for heating electricity to avoid disputes and to enable switching to a lower‑cost electricity tariff if you pay for the electricity yourself.
  • If your flat is colder than expected, ask for evidence of correct commissioning (flow temperatures, COP testing) and an independent assessment if the landlord is unresponsive.
  • Link heating concerns to energy performance — if the property has a low EPC, you have leverage when negotiating repairs, upgrades or rent concessions.

For detail on how to read and negotiate tenancy contract clauses that cover these points, see our guide Understanding Tenancy Agreements: What to Look For.

Heat pumps are a key part of lowering carbon and improving energy efficiency in London homes. For renters, the difference between a well‑designed, well‑serviced system and a rushed retrofit can be the difference between cosy living and cold bills. Check the paperwork, insist on clear responsibilities in your tenancy, and use the negotiation scripts above to protect your comfort and finances through 2026 and beyond.

Sources and further reading

  • UK Heat and Buildings Strategy (government publication) — national target for heat pump rollout.
  • Energy Company Obligation (ECO), Home Upgrade Grant (HUG) and Local Authority Delivery (LAD) schemes — for possible retrofit funding and eligibility.
  • Manufacturer and MCS guidance on heat pump commissioning and servicing.

(Policy and local schemes change frequently — always check the latest government and borough pages for updates.)