The short answer
Clear space around where the indoor and outdoor units will go, make sure the engineers can reach the consumer unit and anything on the pipe route, and plan for the power being off for a while.
A little preparation keeps the day on schedule and protects your belongings. Most of it is about space and access, plus a few decisions that are much easier to settle before anyone arrives with a drill.
Decisions to make first
These are normally agreed at the survey, but it's worth confirming them before the day.
- The indoor unit's position, including which side the pipes leave from. The options are covered in where to put the indoor unit.
- The outdoor unit's position and how the pipes will reach it.
- Where the water will drain, and whether a condensate pump is needed.
- Any pipework visible inside the room, and how it will be covered.
- Permissions. Check whether the outdoor unit needs planning permission. Leaseholders usually need the freeholder's consent, and tenants need their landlord's agreement.
- Shared walls and fences. If anything will be fixed to a wall or fence you share with a neighbour, talk to them first.
If you want to control the system from an app, have your Wi-Fi name and password to hand for the handover.
A quick checklist
| Area | What to do | Why |
|---|---|---|
| Indoor wall | Clear a metre or two, take down pictures | Room to work, less dust on belongings |
| Pipe route | Empty cupboards, clear the loft hatch | Pipes may pass through |
| Consumer unit | Clear the space around it | A new circuit is connected there |
| Outdoor spot | Move pots, bins and furniture | Space for brackets or a stand |
| Access | Gate open, parking nearby | Carrying tools and the unit |
Inside your home
Move furniture back from the wall where the indoor unit will go, leaving a clear working space. Engineers need room for ladders, dust sheets and tools.
Take down pictures and mirrors, and clear any shelves, on that wall. Drilling sends vibration through the wall, so remove anything fragile on nearby walls too, including on the other side of any internal wall the pipes pass through. Take down or tie back curtains and blinds close to the position.
Core drilling is usually done with dust extraction, but some fine dust still gets about. Cover or move electronics, books and anything delicate, and clear a path from the front door to the room.
If the pipes or cable will pass through a loft, cupboard or floor void, empty the cupboard and make sure the loft hatch and the space under it are clear. The same goes for the area around your consumer unit.
Outside
- Clear the spot where the outdoor unit will go, plus space to work around it.
- Make sure the side gate can be opened, or leave a key where the engineers can get it.
- If a base is being laid for a ground stand, point out anything you know is underground there, such as drains or cables.
- Arrange parking close to the house for the van. In a controlled parking zone you may need a visitor permit.
- Let neighbours know about the drilling, especially if a ladder or tower needs to stand on a shared path.
Power, people and pets
Your electricity is usually switched off for a while when the new circuit is connected. Save any work on computers, keep fridge and freezer doors shut, and expect to reset clocks, timers and some alarms. If anyone in your home relies on powered medical equipment, tell the installer in advance so the timing can be planned around it.
Tell the installer about anything you know is hidden in the walls, such as heating pipes, cables, cavity wall insulation or external insulation under the render. In older homes some materials, such as textured ceiling coatings or old boards, can contain asbestos. If you know or suspect there is any where the work will happen, say so before the day.
Keep children and pets away from the work areas, where there will be tools, ladders, cables and open holes. Someone who can make decisions about positions should be home at the start and again for the handover. What happens in between is described in what happens on installation day.
Related guides
- What happens on installation dayInstallers fix the indoor and outdoor units, link them with insulated pipes through a hole in the wall, test the pipework for leaks and clear it of air, then connect the power, run the system and show you how to use it.
- Where to put the indoor unitA wall-mounted indoor unit usually goes high on a wall with clear space around it, where its airflow can reach the whole room without blowing straight at people. The best spot also depends on the route for the pipes and where the condensate can drain.
- Do you need planning permission?Usually not in England, where air-to-air heat pumps that aren't used only for cooling count as permitted development if conditions on number, size, position and noise are met. Listed buildings, flats and protected areas follow different rules.
- How long installation takesA straightforward single-room installation usually takes half a day to a full day. Longer or hidden pipe routes, extra rooms, electrical work and difficult access can each add time, sometimes a day or more.