How long does a heat pump installation take?
One of the practical questions homeowners ask when considering a heat pump is how disruptive the installation will be. Understanding what the process involves and how long it takes helps you plan ahead and know what to expect. This article walks through a typical installation timeline and the factors that can make it shorter or longer.
Before installation comes eligibility. Check if your home may qualify for the £7,500 heat pump grant using our free 2-minute checker.
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Most standard air source heat pump installations take between two and three days to complete. Straightforward replacements in well-prepared properties can sometimes be done in a single day, while more complex jobs involving radiator upgrades, new hot water cylinders, or significant pipework changes can take four or five days. The survey and preparation work that happens before installation day is often just as important as the installation itself.
Note: Timelines vary depending on the installer, the property, and the scope of work agreed. Always confirm the expected duration with your installer before work begins.
The full process — from survey to completion
The installation day itself is only one part of the process. A complete heat pump installation typically involves several stages spread over a number of weeks from first contact to a working system.
Initial survey and heat loss assessment
An MCS-certified installer visits the property to carry out a heat loss calculation, assess the existing heating system, check the EPC status, and confirm where the outdoor unit can be positioned. This typically takes two to three hours.
Quotation and system design
The installer produces a detailed quotation covering the heat pump unit, any necessary radiator upgrades, hot water cylinder, controls, and installation labour. This is also when the Boiler Upgrade Scheme grant eligibility is confirmed.
Pre-installation preparation
Any necessary preparatory work is arranged — such as insulation improvements to satisfy the EPC condition, radiator upgrades, or electrical supply work. Lead times for heat pump units vary by manufacturer and model.
Installation
The main installation work — outdoor unit, indoor unit or cylinder, pipework, controls, and commissioning. This is typically two to three days for a standard job.
Commissioning, handover and grant application
The installer commissions the system, demonstrates how to operate it, and submits the Boiler Upgrade Scheme grant application to Ofgem on your behalf.
What happens during the installation days
Day one — outdoor unit and groundwork
The first day typically focuses on the outdoor work. The heat pump unit is positioned and secured on its mounting base or feet, refrigerant pipework is run from the outdoor unit through the wall to the indoor components, and electrical connections are begun. Any preparatory groundwork — such as laying a concrete base for the unit if required — will also happen at this stage.
Day two — indoor work and pipework
The second day usually involves the indoor installation. This includes connecting the heat pump to the existing or new hot water cylinder, integrating with the central heating pipework, installing any new controls or thermostats, and completing the electrical work. If radiators are being upgraded as part of the job, this work also happens during this phase.
Day three — commissioning and handover
The final stage is commissioning — filling and pressurising the system, checking refrigerant levels, setting flow temperatures correctly, and running the system through its operating modes to confirm everything is working as designed. The installer will demonstrate how to use the controls and thermostat settings, and explain how to get the best efficiency from the system day to day.
What makes an installation take longer
Several factors can extend a heat pump installation beyond the standard two to three days:
- Radiator upgrades throughout the property. If several rooms need larger radiators to work effectively at lower heat pump flow temperatures, replacing them adds significant time to the job.
- New hot water cylinder. Many properties replacing a combi boiler with a heat pump need a hot water cylinder installed for the first time, which involves additional pipework and space preparation.
- Older or complex pipework. Properties with aging or unusual pipework configurations can require additional work to integrate the new system correctly.
- Electrical supply upgrades. Heat pumps require a dedicated electrical supply. If the existing consumer unit is at capacity or needs upgrading, this adds time and typically involves a separate electrician visit.
- Underfloor heating installation. Where underfloor heating is being installed at the same time — often the best match for a heat pump's lower flow temperatures — the groundwork involved extends the timeline considerably.
What makes an installation quicker
Some installations are completed in a single day or a day and a half. This tends to happen when:
- The property already has a hot water cylinder that can be used or easily adapted
- Existing radiators are already adequately sized for heat pump flow temperatures
- The existing pipework is in good condition and compatible with the new system
- The electrical supply is already suitable with no upgrades needed
- The outdoor unit position is straightforward with minimal pipework runs
Will you have heating during the installation?
On most installations, your heating will be off for at least part of the process — typically the day or days when the existing boiler is disconnected and the heat pump is being connected and commissioned. Installers are usually able to plan around this, and in most cases the new system is operational by the end of the final installation day.
If the installation is happening during colder months, it is worth discussing this with your installer in advance so they can plan the work to minimise the time the heating is off, or advise on temporary arrangements if needed.
How long before you get hot water back
Hot water is typically restored on the same day as the system is commissioned, which is usually the last installation day. If a new hot water cylinder is being installed and needs to heat up for the first time, there may be a few hours' wait before hot water is available at full temperature. Your installer will confirm this during the handover.
After the installation — the grant application
Once the installation is complete and the system is commissioned, your MCS-certified installer submits the Boiler Upgrade Scheme grant application to Ofgem on your behalf. You do not need to do anything for this step — the grant amount will have already been deducted from your installation cost. Ofgem processes the application and pays the installer directly.
Thinking about a heat pump installation? Start by checking whether your home may qualify for the £7,500 Boiler Upgrade Scheme grant using our free eligibility checker.
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A standard air source heat pump installation takes two to three days on site. The full process from initial survey to a working system typically spans four to eight weeks, depending on preparation work, equipment lead times, and any pre-installation improvements needed. More complex jobs involving radiator upgrades, new cylinders, or electrical work take longer. Your installer will give you a clear timeline as part of the quotation process.
Related articles
- £7,500 heat pump grant — full guide and eligibility overview
- Boiler Upgrade Scheme eligibility rules explained
- Heat pump vs gas boiler running costs in the UK
- Can I get a heat pump grant for a detached house?
- Can I get a heat pump grant for a terraced house?
- What EPC rating do I need for the heat pump grant?