How long does air source heat pump installation take?

A typical air source heat pump installation takes 2–4 days from start to finish. Day 1 covers external unit installation and pipework. Day 2 covers the internal hot water cylinder and controls. Day 3 (if required) covers any radiator upgrades, commissioning, and handover. From initial survey to installation day, allow 4–8 weeks for grant paperwork, equipment ordering, and scheduling.

What happens during a heat pump survey?

A heat pump survey typically takes 60–90 minutes. The surveyor will: measure every room to calculate heat loss; check existing radiator sizes and assess whether upgrades are needed; inspect the boiler, hot water cylinder, and pipework; review the EPC rating and recommend insulation improvements; assess the electrical supply; confirm BUS grant eligibility; and discuss unit siting options. You receive a detailed written quote including all equipment and any preparatory works.

What questions will the surveyor ask during a heat pump survey?

Typical questions include: What is your current heating system and when was it installed? What is your current energy spend? Have you had an EPC assessment? Do you have a loft, and is it insulated? What is the wall construction (cavity or solid)? Do you have a hot water cylinder? How many people live in the house? Do you have underfloor heating? Are there any planning constraints (listed building, conservation area)?

Do I need to move out during heat pump installation?

No. Heat pump installation is carried out while the house is occupied. There will be a period (typically 4–8 hours) on the second day when heating and hot water are unavailable while the old boiler is disconnected and the new heat pump connected. We plan this around school runs and work schedules where possible, and we always ensure the system is operational before the engineer leaves for the day.

What is an MCS certificate and why do I need it?

MCS (Microgeneration Certification Scheme) is the Government-recognised quality standard for small-scale renewable energy installations. Your installer must be MCS-certified to install a heat pump, and the installation must be carried out to MCS standards. Without an MCS certificate, you cannot claim the Boiler Upgrade Scheme grant (£7,500) or the Smart Export Guarantee. We handle all MCS paperwork and provide your certificate at handover.

What happens on heat pump installation day?

Day 1 typically starts at 8am. The outdoor unit is positioned and secured on its base, refrigerant pipework is run to the plant room or airing cupboard, the hot water cylinder is installed, and electrical connections are made. By end of day 2, the system is commissioned — refrigerant pressure-tested and charged, controls configured, and you receive a full walkthrough of the heat pump controller and app.

Will I need to change my hot water cylinder for a heat pump?

Probably. Most gas boiler systems use a combination boiler (combi boiler) that heats water on demand, which does not work with a heat pump. Heat pumps work best with a hot water cylinder that stores pre-heated water. A standard 200–250 litre unvented cylinder costs £800–£1,500 installed. This is typically included in our heat pump installation quote.

How does the Boiler Upgrade Scheme grant work in practice?

We handle the BUS grant application on your behalf. After you confirm you want to proceed, we apply for the grant voucher through the MCS portal. Once the voucher is issued (typically 2–4 weeks), we schedule the installation. The £7,500 is deducted from your invoice — you never pay it and then claim it back. You just pay the net price after the grant is applied.

Installation Guide | Updated March 2026 | 7 min read

Heat Pump Installation: What to Expect

From your first enquiry to commissioning day — a complete, honest guide to the heat pump installation process, including what the surveyor checks, how the BUS grant works in practice, and what happens hour by hour on installation day.

At a Glance

4–8 weeks

Survey to installation

2–4 days

Installation duration

£7,500

BUS grant

The Installation Process: Step by Step

Initial Enquiry and Survey Booking

Contact us to describe your property and current heating system. We schedule a free home survey within 1–2 weeks. No commitment needed at this stage.

The Home Survey (60–90 mins)

An MCS-certified engineer visits your home. We calculate room-by-room heat loss, assess radiators, inspect the hot water system, check the electrical supply, confirm BUS eligibility, and discuss siting options for the external unit.

Your Detailed Quote

Within 3–5 days, you receive a written quote covering all equipment (heat pump model, cylinder, controls), any preparatory work (radiator upgrades, cylinder replacement), grant deductions, and a clear net price.

BUS Grant Application

Once you confirm you want to proceed, we apply for the £7,500 BUS voucher through the MCS portal. This takes 2–4 weeks. We handle all the paperwork — you do not need to contact OFGEM or the government directly.

Pre-Installation Preparation

We confirm the installation date, advise you on any preparation needed (clear the airing cupboard, arrange access to the outdoor unit location), and order all equipment for delivery to site.

Installation Day 1: External Unit and Pipework

Engineers arrive at 8am. The outdoor unit is secured on its base or wall bracket. Refrigerant pipework is run from the outdoor unit to the plant room. The old boiler is decommissioned.

Installation Day 2: Internal Equipment and Connections

The hot water cylinder is installed (if required). Electrical connections are made to the consumer unit. Controls are wired and mounted. Radiators are upgraded if included in the scope.

Commissioning and Handover

The system is pressure-tested, refrigerant is charged, and the heat pump is started up for the first time. The engineer configures the controller settings for your home and walks you through the app and controls. You receive your MCS certificate, building regulations compliance certificate, and warranty documents.

What Does the Surveyor Check?

The home survey is the most important step. A thorough survey ensures you get the right heat pump, the right radiators, and an accurate quote. Here is what our MCS-certified engineers check:

Every room

Room dimensions
Window area and type
External wall construction
Ceiling height
Existing radiator size
Draft points and door gaps

Heating system

Current boiler model and age
Hot water cylinder size and type
Pipework condition
Pump and expansion vessel
Radiator types (K1, K2, K3)

Electrics

Consumer unit capacity
Available circuit space
Main fuse rating
Distance to heat pump location
EV charger conflicts

Property

EPC rating (must be D or above for standard BUS)
Loft insulation depth
Cavity vs solid walls
Planning constraints (listed, conservation area)
Outdoor unit siting options

Timeline from Enquiry to Switch-On

1–2 weeks

Enquiry to survey

We aim to visit within a week of enquiry

3–5 business days

Survey to written quote

Detailed itemised quote with all options

2–4 weeks

Quote acceptance to BUS voucher

We apply for the £7,500 grant once you confirm

1–3 weeks

Equipment ordering

Most major brands available within 2 weeks

2–4 days

Installation days

Typical for residential ASHP with cylinder

Half day

Commissioning and handover

Included in installation programme

Total from first enquiry to a working heat pump: typically 6–10 weeks. In urgent cases (boiler failure), we can sometimes fast-track the process.

Ready to Get Started?

Our free survey is a no-obligation visit by an MCS-certified heat pump engineer. You will receive a detailed written quote, BUS grant eligibility confirmation, and a clear explanation of what the installation will involve at your property.

Book a Free Survey Heat Pump Costs Guide

Frequently Asked Questions

Heat Pump Installation Service BUS Grant Guide Heat Pump Costs Guide Radiator Sizing Guide

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