How long does a heat pump installation take?

You’ve decided to make the switch. Naturally, the next question is: how soon can it happen? The answer has two parts, and homeowners are often surprised by both. The on-site install is measured in working days. Getting from first enquiry to switch-on takes rather longer.

Here’s how the whole journey typically unfolds, so you can plan around it properly.

Week one: the survey

Everything starts with a home visit from a qualified engineer, usually booked within a week or two of your first enquiry. This isn’t a hard sell — it’s a proper look at your home, taking around an hour to an hour and a half. They’ll measure rooms, check your radiators, look at your hot water setup, and work out where the outdoor unit could sit. For a fuller checklist, see what happens during a heat pump survey.

You’ll walk away from this visit with a much clearer picture of your own home, even before any quote arrives — including whether planning permission is likely to be needed.

Weeks two to four: the quote and the paperwork

A written quote usually follows within a few days of the survey, covering the equipment, any extra work like radiator upgrades, and the price after any grant is deducted.

This is also when the behind-the-scenes admin happens. If you’re using government support in England and Wales, your installer typically applies for the Boiler Upgrade Scheme on your behalf, and approval can take a couple of weeks. Scotland’s Home Energy Scotland route is applicant-led and follows a different timeline. This stretch may feel like downtime, but it’s useful: equipment is ordered and your installation date is confirmed.

From that first survey to a confirmed installation date, many homeowners are looking at somewhere between a few weeks and a couple of months. It varies by installer and by how busy the season is — heat pump bookings tend to fill up faster in autumn, when people are thinking ahead to winter.

Installation day (or days)

This is the part people picture when they think “installation.” For a typical air source heat pump, on-site work usually takes around 5–7 working days, plus time to connect into your heating system. Ground source jobs take longer because of excavation. Weather and property size can stretch or shrink that window.

Days are often split across outdoor unit and pipework, indoor cylinder and controls, then any radiator upgrades plus final testing and a walkthrough. You don’t need to clear your diary for every hour — most of it is engineers working in the garden, loft, or airing cupboard — but you’ll want to be around for the final handover.

Once the install window starts, most air source jobs wrap up within about 2–3 weeks from start to finish — covering the on-site days plus connecting into your heating system. That window is separate from the earlier survey-and-paperwork lead time, which can add several more weeks before anyone arrives on site.

What causes delays

Most hold-ups happen before installation day, not during it:

• Grant processing taking longer than expected in busy periods — nothing you can speed up from your end, just worth building a little slack into your plans.
• Extra work coming to light, such as an electrical supply upgrade. A good survey should flag this early rather than as a surprise on the day.
• Installer availability, especially in the run-up to winter. Booking a survey a season ahead of when you want the work done isn’t overkill — it’s realistic.

None of these are uniquely heat-pump problems — they’re the same kinds of things that can hold up any significant home improvement.

Planning around installation day itself

A few practical things make the days smoother. Your heating and hot water will likely be off for at least part of the work, so it’s not the week to schedule a big family gathering. Clear access to your loft, airing cupboard, and garden helps. If you’ve got pets, a bit of forward planning for a noisier day with people in and out is worth it.

Beyond that, there’s very little for you to do. This is one of those home improvements where the waiting is the biggest task on your list.