My heat pump journey part two: making a plan

In part one of this series, I looked at preparation. How to make your home ready for a heat pump. I did this by insulating my 1930s terrace on all sides. I insulated walls, floors, roof, so much that it went up from an EPC D rating to a C.

This second article is about how to pick a heat pump supplier, get a survey done – and figure out if it’s even doable.

A huge £7,500 discount

If you’re replacing a gas boiler (or other fossil fuel-based heating system) in England you should be eligible for the Boiler Upgrade Scheme (BUS). This knocks £7,500 off your installation bill.

For me, this brought the cost of a heat pump down so much that it was similar to the cost of a replacement boiler. But you must use an MCS certified installer who is registered for the BUS to get the funding.

This also means you know you’re getting someone who’s competent and that the products meet standards.

The discount comes off the bill. So you don’t have to pay the full amount and claim the money back. But you will need to sign some forms to say that the work has been done and the discount has been applied.

Picking a supplier

I started researching heat pumps. Soon after, my social media was full of ads from energy companies and heat pump makers.

I didn’t want to use a little company that I’d never heard of to install it. I decided it was best to pick a well-respected supplier rather than fixate on a specific make and model of heat pump.

The supplier visits and does a thorough survey. It’s only after this that you’ll start talking about makes and models.

I found several certified installers near me, but settled on energy company Octopus Energy in the end. The company is known for its flexible tariffs and eco options.

Octopus Energy has committed to heat pumps in a big way, so there’s also an economy of scale that drives prices down.

You don’t have to change electricity supplier but I chose to, to take advantage of its heat pump friendly Cosy Octopus tariff.

You start by filling in an online survey to get a quote, pay a refundable £200 deposit and request a home survey.

The survey

On the survey day, Octopus Energy sent two people over.

One was armed with an app and tape measure to survey the house and measured every wall and window, even the radiators –  they were on a mission to find out how much heat the house needed and how much heat the radiators would put out.

The other was a heating engineer – looking at where to position the heat pump and how to fit it to my system.

An air source heat pump needs a unit outdoors to gather heat energy from the air (it looks like air conditioning unit) and a large water storage cylinder indoors.

My house was well insulated but finding space for the indoor equipment was a challenge. Like many people, I had a combi boiler and no cylinder… and no room for one.

No space for a cylinder

When we extended the house and built the kitchen in 2017, it didn’t occur to me that I’d ever need space for a cylinder.

In fact, the bespoke kitchen was built around the aging combi boiler; I just assumed that I’d find a new one of a similar size – I didn’t think about heat pumps.

The outdoor unit

The easy part was agreeing where the outdoor unit should sit.

My house is end of terrace, so it has a side passage. This made it possible to have a back-to-back installation, with the outdoor unit in the side passage just the other side of the wall from the old boiler.

Planning permission wasn’t needed – the rules are that it must be at least 1m from your neighbour’s boundary (which it was) and not loud near any windows (theirs or yours).

Of course, it’s different for listed buildings and conservation areas.

Mine didn’t need planning permission but I discussed it with my neighbour all the same and she was supportive.

The indoor unit

Inside was so much tougher.

The Jonathan Maker kitchen, built bespoke in 2017, fitted everything in perfectly. There was no spare room – so I had to sacrifice something.

I considered various places around the house and decided that the heat pump belonged where the combi boiler was being removed, for a back-to-back installation.

This would mean losing a cupboard’s worth of space, including my tumble dryer.

The space was still extremely tight: taller but narrower than most heat pump cupboards.

The surveyor put a lot of thought into it and concluded that it was possible, literally at a squeeze.

I then emptied another kitchen cupboard and moved the tumble dryer into it – losing  storage space but no appliances.

Other changes

Meanwhile the other surveyor was visiting every room, measuring the walls, windows and radiators, and asking me questions.

All the data gets entered into an app and then the results tell you what modifications your heating system needs.

This bit was amusing. Both surveyors saw my 1930s house and imagined that I’d need to replace a lot of radiators.

But I’d done such a good job of insulating the house than only two radiators needed replacing. This was a pleasant surprise.

Radiators get replaced in order to put out more heat so you might get a larger radiator or one that discreetly has more panels.

This is because heat pumps circulate water at a lower temperature than gas boilers (around 45-50°C rather than 65-70°C), so you sometimes need larger radiators in order to put out enough heat.

The surveyors from Octopus Energy were stunned by the results – they even double-checked them because my house doesn’t look like an eco-home.

It was really good news, my preparation had paid off and I was quoted just £2,400 for the installation, which covered everything, including the radiator changes.

The total came to £9,900 but with £7,500 deducted, thanks to the Boiler Upgrade Scheme.

At £2,400, the cost was equivalent to a new boiler and, seeing as my old combi was broken, it was a no-brainer.

I’d lose some cupboard space but I’d finally be able to get off fossil fuels and hopefully save on energy bills.

The alternative, a new boiler, would be easier but would commit me to another decade of fossil fuels and reliance on gas prices – instead, this was a good plan in terms of cash and the climate.

Will a heat pump work in your home?

If you have the space indoors and out, I feel a heat pump can work in any home.

The caveat is that you might have to throw cash at it. My 1930s house was really well insulated – as documented in part one of this series – but many aren’t.

Either spend money on insulation, so less heat is lost, or spend money on radiators, to put more heat out.

Modern homes are better insulated so tend to be better candidates.

Though if you’re unlucky enough to have ‘microbore’ narrow central heating pipes that were popular in the 1970s and 1980s, you’ll likely need new pipework.

Next steps

The Octopus Energy surveyors left me with a plan, costed out, that detailed the heat pump equipment and performance. I just had to read, sign it and book a date.

Considering my old combi boiler had died, so we had no heating and no hot water, I couldn’t wait.

I had to empty the double cupboard and Jonathan Maker removed the bespoke cabinetry, promising to return and redo it once the heat pump was in place.

I was nearly there. In the third article in this series, I’ll talk about the installation day itself. We were finally getting a heat pump… or were we?

Meanwhile, if you’re interested in heat pumps, take a look at this heat pump explainer, this overview of heat pump installation costs and this article on heat pump running costs.