What actually happens when you get a heat pump? From survey to switch-on
Thinking about a heat pump but not sure what you’re actually signing up for? You’re not alone.
So here’s a step-by-step look at what happens when Custom Heat & Cool installs an air source heat pump, from the first visit to the day it’s switched on.
Step 1: A home survey
Everything starts with a visit from one of our team. A heat pump only works well if it’s sized correctly for your home, so this isn’t a quick look round and a guess.
We’ll:
- Measure your rooms and work out how much heat each one loses (this is called a heat loss calculation)
- Check your existing radiators and pipework to see what can stay and what needs upgrading
- Look at where the outdoor unit could sit, and where a hot water cylinder would go
- Talk through how you use your heating, so the system suits the way you live
If a heat pump isn’t the right fit for your home, we’ll tell you. We install boilers too, so we’ve no reason to push you one way or the other.
Step 2: Your quote and the grant paperwork
After the survey you’ll get a clear, itemised quote showing exactly what’s included.
If you’re eligible for the Boiler Upgrade Scheme, we take care of the application for you. As an MCS-certified installer, we apply for the grant on your behalf and it comes straight off your quote, so you never have to chase it yourself.
Step 3: Installation
Every home is different, so we’ll give you a plan for your install before we start. In most homes, the work looks like this:
- Outdoor unit fitted. It sits on a solid base or wall brackets outside, usually against a wall where it’s out of the way.
- Hot water cylinder installed. Heat pumps heat your water through a cylinder, so if you have a combi boiler now, we’ll find the best spot for one.
- Radiators upgraded where needed. Heat pumps run at lower temperatures than boilers, so some rooms may need a larger radiator to stay just as warm. Your survey tells us exactly which ones.
- The old system was removed. We take away your old boiler or oil tank (where agreed) and leave everything tidy.
- Controls set up. We fit your thermostat and controls and set them up around your routine.
Our engineers treat your home like their own throughout: dust sheets down, tidy work areas, and we’ll keep you updated every day.
Step 4: Switch-on and handover
Once everything is fitted and tested, we’ll switch your system on and walk you through it. We’ll show you how your controls work, what settings to use, and what to expect from a heat pump day to day. You’ll also get all your paperwork, including your MCS certificate and warranty details.
Living with your heat pump: what to expect in the first winter
A heat pump works a little differently from a boiler, and knowing that up front makes the first few months much easier.
- Low and steady wins. Heat pumps are most efficient running gently for longer, rather than blasting heat for an hour in the morning and evening.
- Radiators feel warm, not hot. That’s normal. The room still gets to temperature, it just does it more gradually.
- You might see a little steam. On cold, damp days the outdoor unit defrosts itself now and then. A puff of vapour is completely normal.
- Leave the settings alone at first. Give it a couple of weeks before you start adjusting things. If something doesn’t feel right, give us a call.
Common worries, answered
Is it noisy? Modern units are quiet, with a low hum similar to a fridge. We’ll position yours to keep any sound away from windows and neighbours.
Will I need all new radiators? Not usually. Most homes need a few upgrades rather than a full replacement. Your survey will show exactly which ones.
Does it work when it’s freezing? Yes. Heat pumps are designed to keep working well below zero, and they’re widely used in much colder countries than ours.
Does it need servicing? Yes, an annual service keeps it running efficiently and protects your warranty, just like a boiler.
Help with the cost
The government’s Boiler Upgrade Scheme offers £7,500 towards an air source heat pump for eligible homes in England and Wales.
If your home is heated by oil or LPG and isn’t on mains gas, there’s an extra £1,500 available until March 2027, bringing the grant to £9,000. If that’s you, it’s worth getting your survey booked sooner rather than later.
The new government-backed Warm Homes Loan can also help spread the remaining cost through participating lenders. Installs must be carried out by an MCS-certified installer, like us. We’re happy to talk you through your options.
Ready to find out if a heat pump is right for your home?
Book a no-obligation home survey with our team. We’ll give you honest advice, a clear quote, and take care of the grant paperwork for you.
Call us on 0330 383 0000 or request your free quotation online.
