Should You Finally Buy a Heat Pump? What Has Changed?

The question is no longer simply “Do heat pumps work?” — it is “Will one work well in my house?”

For several years, discussion about heat pumps has tended to become polarised remarkably quickly.

One side says they are the obvious future of domestic heating.

The other says they are expensive, noisy, incapable of heating older houses and certain to produce enormous electricity bills.

Neither position is particularly helpful if you are standing in your own kitchen wondering whether to replace a perfectly conventional gas boiler.

By 2026, we really ought to have moved beyond asking whether heat pumps work.

They clearly do.

The more useful questions are:

How much heat does your particular house actually lose?
Can your radiators deliver enough heat at a lower water temperature?
What electricity tariff will you use?
What heating system are you replacing?
How good is the proposed design?
What will the installation cost after grants?
Are you prepared for the different way a heat pump heats a home?

That last point matters enormously.

A heat pump is not simply an electric boiler with a fan bolted onto the side of the house.

And buying one on that assumption is one of the easiest ways to be disappointed.

So What Has Actually Changed by 2026?

Quite a lot.

Heat pumps themselves have improved.

Installers have accumulated more experience.

There is greater understanding of low-temperature heating.

Smart tariffs, batteries and solar generation have become increasingly relevant.

And government support remains substantial.

In England and Wales, the Boiler Upgrade Scheme currently provides £7,500 towards an air-to-water heat pump or ground-source heat pump. Some qualifying off-gas properties replacing oil or LPG can receive £9,000, while an air-to-air heat pump can now attract a smaller grant of £2,500.

That changes the calculation considerably.

A technology that may once have required a very large additional investment can now be financially much closer to the cost of replacing an entire conventional heating system.

But there is another change which is perhaps even more important.

We are getting better at asking the right question.

Not:

“What size heat pump shall we bolt onto this house?”

But:

“How should this house be designed to work efficiently with a heat pump?”

That is a much better starting point.

First: A Heat Pump Does Not Create Heat in the Same Way as a Boiler

A gas boiler might burn one unit of gas and turn most of it into useful heat.

A heat pump works differently.

It uses electricity to move heat from outside the building to inside it.

If a heat pump has a coefficient of performance of 3, then roughly:

1 kWh of electricity produces 3 kWh of heat.

At a COP of 4:

1 kWh of electricity produces 4 kWh of heat.

That sounds wonderful.

But COP is not a fixed number printed on the machine that you will achieve every minute of every winter.

It changes with conditions.

In particular, the greater the temperature difference between the outside air and the water you are asking the heat pump to produce, the harder the machine must work.

That brings us to perhaps the most important number in any heat-pump quotation.

Ask About Flow Temperature

Flow temperature is the temperature of the water leaving the heating system and travelling towards your radiators or underfloor heating.

Traditional boiler systems have commonly operated at relatively high temperatures.

Heat pumps generally become more efficient when asked to produce cooler water.

That means a home that remains comfortable with water circulating at perhaps 35°C to 45°C is potentially a very good candidate.

A home requiring extremely hot water through relatively small radiators is much more challenging.

Energy Saving Trust specifically recommends lowering heat-pump flow temperatures where possible because this can significantly improve efficiency and therefore running costs. It also highlights weather compensation — automatically reducing water temperature when outdoor conditions are milder — as an important part of efficient heat-pump operation.

So when somebody quotes for a heat pump, one of my first questions would now be:

“What design flow temperature are you proposing?”

If the answer is vague, that would concern me far more than the manufacturer's badge on the heat pump.

Your Radiators Matter More Than You Might Think

Here is something many householders discover only when obtaining a heat-pump quotation.

Your existing radiators may have been designed around much hotter water.

Put cooler water through them and they produce less heat.

That does not necessarily mean replacing every radiator.

Some radiators in British homes are already considerably larger than strictly necessary.

Others may need upgrading.

A room-by-room heat-loss calculation allows an installer to determine how much heat each room needs and whether the existing radiator can supply it at the intended flow temperature.

This should not be guesswork.

MCS heat-pump design standards require building heat-loss calculations, and its guidance stresses that room-by-room calculations should consider the construction, room dimensions, ventilation, desired internal temperature and local winter design temperature.

This is why I would be wary of anyone simply looking at your existing boiler and saying:

“That's a 24 kW boiler, so we'll fit something equivalent.”

The boiler rating tells us remarkably little about the actual heat loss of the house.

Bigger Is Not Automatically Better

We are accustomed to thinking that buying something bigger gives us a useful safety margin.

Heating systems do not necessarily work that way.

An oversized heat pump may cycle on and off unnecessarily rather than operating steadily.

An undersized one may struggle during very cold conditions.

The objective is therefore not:

the biggest machine you can afford.

It is:

a correctly designed machine matched to the building's heat loss.

This is one of the areas where installation quality can matter more than the brand name on the casing.

Insulation Still Matters — But You Do Not Necessarily Need a Passivhaus

One of the persistent heat-pump myths is that they only work in ultra-modern houses with extraordinary levels of insulation.

That is too simplistic.

Older properties can use heat pumps successfully.

What matters is how much heat the building loses.

Imagine two houses.

House A loses 6 kW of heat during a particular cold spell.

House B loses 14 kW.

The second house needs a much larger heating system and substantially more energy.

Improving insulation reduces that requirement regardless of whether the heat comes from gas, oil, electricity or a heat pump.

So I would normally look at inexpensive improvements first.

Loft insulation.

Draught sealing.

Cavity-wall insulation where appropriate.

Improved windows where they genuinely need replacing.

Insulating accessible pipework.

Closing obvious thermal leaks.

You do not necessarily have to turn the property into a sealed laboratory.

But every kilowatt of heat you stop escaping is a kilowatt your heating system does not have to replace.

There Is an Interesting Test You Can Try Before Buying Anything

If you currently have a conventional boiler with radiators, try experimenting with its flow temperature.

Do this sensibly and preferably during reasonably cold weather.

Gradually reduce the central-heating flow temperature and see whether the house remains comfortable.

Perhaps try:

60°C.

Then 55°C.

Then 50°C.

Possibly lower.

Do not confuse central-heating flow temperature with domestic hot-water storage requirements.

What you are trying to discover is whether the house can maintain comfort using cooler radiators.

If it remains warm at 50°C, that tells you something useful.

If it remains warm at 45°C, that tells you something even more interesting.

You have effectively performed a crude real-world experiment on how suitable your emitters and building might be for lower-temperature heating.

It is not a substitute for proper heat-loss calculations, but it may start a much more intelligent conversation with an installer.

But What About Running Costs?

This is where simplistic claims become dangerous.

People sometimes say:

“A heat pump is three times as efficient as a boiler, therefore heating will cost one-third as much.”

That calculation ignores the fact that electricity costs considerably more per kilowatt-hour than gas.

For the Ofgem price-cap period beginning 1 October 2026, average Direct Debit prices are approximately:

Electricity: 26.32p/kWh

Gas: 7.97p/kWh

although individual tariffs and regions vary.

Suppose a heat pump achieved a COP of 3.

The rough electricity cost of producing 1 kWh of heat would be:

26.32p / 3 = 8.77p

At COP 4:

26.32p / 4 = 6.58p

Now compare gas.

If a boiler turned 90% of its gas into useful heat, then approximately:

7.97p / 0.90 = 8.86p per useful kWh of heat

Suddenly the picture becomes much clearer.

At those illustrative prices, a heat pump averaging COP 3 is in broadly similar territory to a 90%-efficient gas system for the energy itself.

At COP 4, the heat pump comes out considerably better.

But a poorly designed system operating inefficiently can quickly lose that advantage.

This is why system performance matters.

The Electricity-to-Gas Price Ratio Matters

There is actually a useful number hiding in the tariff.

Using those October 2026 capped unit rates:

26.32 / 7.97 = approximately 3.3

Electricity therefore costs roughly 3.3 times as much per raw kilowatt-hour as gas under this example.

That does not mean the heat pump needs a COP of exactly 3.3 to compete, because a gas boiler does not convert every kilowatt-hour of gas into useful room heat.

But it gives us a valuable way of thinking.

The better the heat pump's seasonal efficiency, the more attractive the economics become.

And that depends partly on:

flow temperature;
weather compensation;
radiator sizing;
heat-pump sizing;
control strategy;
insulation;
hot-water requirements;
outdoor temperature;
installation quality.

It is therefore perfectly possible for two neighbours with apparently identical heat pumps to experience rather different running costs.

Smart Electricity Tariffs Change the Calculation Again

Comparing only standard electricity and gas rates increasingly misses part of the picture.

A heat pump uses a great deal of electricity over an entire heating season.

That means the tariff can be extremely important.

Time-of-use tariffs may allow householders to obtain cheaper electricity during certain periods.

Some tariffs are specifically designed for households with heat pumps, EVs or battery storage.

Energy Saving Trust also points to the potential advantages of combining heat pumps with solar generation, batteries and time-of-use tariffs.

That particularly interests me because it reflects what I have gradually done in my own house.

I no longer think of the heat pump as an isolated appliance.

Our home is now essentially an integrated electrical energy system.

We have solar panels.

Battery storage.

An air-source heat pump.

And we have removed gas altogether.

Once you begin thinking in those terms, the question changes.

Rather than simply:

“What does one kilowatt-hour of electricity cost?”

you start asking:

“When will I buy that electricity, when will I generate it, when will I store it and when will I use it?”

That is a very different energy model from the traditional house with a gas boiler and an electricity meter.

Solar Panels Help — But Remember Winter

Solar power and heat pumps sound like perfect partners.

To an extent they are.

But there is an inconvenient seasonal problem.

Your heating requirement is usually greatest when solar generation is lowest.

A beautiful sunny April afternoon might allow solar panels to make a substantial contribution to heating.

A dark, wet December evening is rather different.

That does not make solar irrelevant.

Far from it.

But it does mean that nobody should calculate annual heat-pump running costs on the assumption that most winter heating will magically come from rooftop solar.

You have to look at the whole year.

Batteries Can Be Useful — But They Do Not Manufacture Energy

The same applies to batteries.

My own system has substantial battery storage, and that can change how electricity is bought and used.

A battery can charge when electricity is cheap and discharge when electricity is expensive.

It can absorb excess solar production.

Potentially it can help support a heat pump through expensive tariff periods.

But the battery is moving energy through time.

It is not creating it.

During a long, cold spell you may still need substantial grid electricity.

That is why the combination of heat pump, solar and battery can be excellent — but only when the economics are modelled realistically.

Heat Pumps Prefer Steady Heating

Another behavioural change catches some people out.

Many of us grew up with boilers that behaved rather like enormous kettles.

The house becomes cold.

The boiler fires.

Very hot radiators rapidly heat the rooms.

Then everything turns off again.

Heat pumps often work best rather differently.

They may operate for longer periods at lower temperatures, gently replacing heat as the building loses it.

That sometimes produces one of the strangest complaints about heat pumps:

“The radiators aren't hot.”

They may not need to be.

The important question is:

“Is the room warm?”

A radiator does not receive bonus points for being too hot to touch.

Its job is to transfer enough energy into the room to balance the heat leaving the room.

If it can accomplish that efficiently with moderately warm water, the system may be operating exactly as intended.

Hot Water Needs Some Thought Too

Space heating is only part of the story.

Many gas combi boilers provide almost unlimited hot water on demand.

A typical heat-pump installation uses a hot-water cylinder.

That has implications for:

cylinder size;
cupboard space;
household bathing habits;
recovery time;
sterilisation cycles;
immersion-heater settings.

A four-person household with several showers every morning has different requirements from a retired couple using relatively little hot water.

Again, there is no universal answer.

The system should be designed around the household.

Installation Quality May Be the Biggest Variable of All

By 2026, I think this has become one of the central lessons of the heat-pump debate.

A good heat pump badly designed may give disappointing results.

A properly designed system can perform extremely well.

Consider everything the designer has to get right:

the building heat loss;

the heat pump size;

radiators;

pipe sizes;

water flow;

hot-water cylinder;

controls;

weather compensation;

system balancing;

commissioning.

That is why I would spend at least as much time choosing the installer as choosing the heat-pump manufacturer.

MCS guidance places significant emphasis on proper building heat-loss calculations and emitter design rather than simply selecting equipment from its headline rating.

Questions I Would Ask an Installer in 2026

If I were considering a heat pump now, these are the questions I would want answered clearly.

What is the calculated design heat loss of my house?
Can I see the room-by-room heat-loss calculation?
What flow temperature is the system being designed around?
Which radiators need replacing, and why?
What seasonal performance do you predict?
What happens at the design outdoor temperature on the coldest winter days?
How will domestic hot water be produced?
Will weather compensation be enabled and commissioned correctly?
What electrical upgrades are required?
What happens if the system does not keep the house warm as designed?
What grant applies to this property?
What maintenance and servicing will be required?

A competent installer should welcome these questions.

What About Noise?

Modern air-source heat pumps contain fans and compressors, so they are not silent.

Neither are modern boilers, refrigerators, air-conditioning systems or traffic outside your house.

The important questions are where the outdoor unit will be positioned and what its actual sound characteristics are.

Poor placement beside a bedroom window is obviously less desirable than careful positioning away from sleeping areas and neighbouring properties.

Planning requirements and MCS sound assessment rules also need to be considered.

Noise should certainly be part of the design.

It should not automatically be a reason to reject the technology.

What Type of House Is Most Suitable?

There is no single ideal property, but some circumstances make the decision easier.

A well-insulated modern house

Potentially excellent.

Heat losses may be low, radiators or underfloor heating may already be suitable for low flow temperatures, and required heat-pump capacity may be modest.

A reasonably insulated conventional house

Also potentially very good.

Some radiators may need enlarging and basic insulation improvements may be worthwhile.

This probably describes a very large number of British homes.

A large old house with small radiators

More challenging.

That does not mean impossible.

But a thorough heat-loss study becomes particularly important.

Radiator upgrades, insulation work or higher-temperature equipment may need consideration.

A property currently using oil or LPG

Potentially particularly interesting.

In England and Wales, qualifying off-gas properties replacing oil or LPG can currently receive a grant of up to £9,000 under the Boiler Upgrade Scheme.

A flat with nowhere sensible for an external unit

Possibly more difficult.

Alternative technologies or communal heating may be more suitable.

A home needing a boiler replaced immediately

The decision may depend heavily on how quickly proper heat-pump design and installation can be arranged.

You should not allow urgency to turn a major heating investment into a badly designed one.

Should You Replace a Perfectly Good Boiler Tomorrow?

Not necessarily.

Environmental arguments sometimes become confused with the idea that everything old must immediately be thrown away.

That is not always sensible.

If you have an efficient boiler that is only a few years old, the most rational short-term investment might be to improve insulation, reduce flow temperatures, understand your heating demand and prepare the house for its eventual replacement.

On the other hand, if your boiler is approaching the end of its life and you are about to spend several thousand pounds replacing the entire heating system anyway, that is exactly the moment when I would investigate a heat pump seriously.

That is particularly true because the grant changes the capital-cost calculation substantially.

Do Not Compare a Heat Pump Quote With the Price of a Boiler in a Box

This is another misleading comparison.

You may see:

“New boiler: £2,500.”

“Heat pump: £12,000.”

Therefore the heat pump appears absurdly expensive.

But ask what each figure includes.

Does the heat-pump installation include:

radiator replacement?

a new hot-water cylinder?

pipework changes?

controls?

electrical work?

removal of old equipment?

system design?

commissioning?

And then deduct the applicable grant.

The fair comparison is the complete installed heating-system cost, not simply the retail price of two pieces of equipment.

What Has Changed Most? Perhaps Our Understanding

The biggest improvement since the early heat-pump debates may not actually be technological.

It may be our understanding.

We now have much better evidence that the question is not simply whether a heat pump is “good” or “bad”.

A heat pump is part of a heating system.

And the heating system is part of a building.

And increasingly, the building is part of a wider electrical-energy system including solar generation, batteries, EV charging and smart tariffs.

That systems approach is far more useful.

My Own Experience Has Changed How I Think About Heating

Living with a heat pump changes your perspective surprisingly quickly.

I no longer think about heating as something that suddenly switches on and blasts huge quantities of heat into the house.

I increasingly think about energy flows.

How much heat is the building losing?

How warm does the heating water actually need to be?

How much solar electricity are we generating?

How much energy is stored in the batteries?

When is grid electricity cheapest?

How much energy are we using overnight?

Those questions become interconnected.

And that is perhaps where domestic heating is heading generally.

Not simply towards a different boiler.

Towards homes that manage energy.

So, Should You Finally Buy a Heat Pump?

Perhaps.

And I think that is actually a much more useful answer than an automatic yes.

A heat pump could make excellent sense if:

your house has manageable heat losses;

the radiators can operate effectively at reasonably low temperatures;

the installation is properly designed;

you qualify for substantial grant support;

and the predicted running costs work with your tariff.

It may make less sense if extensive building modifications are required, the property has unusually high heat losses, installation is physically difficult, or the proposed system relies on very high flow temperatures.

But do not reject a heat pump merely because your house is old.

And do not buy one merely because somebody tells you they are the future.

Measure.

Calculate.

Design.

Then decide.

The Most Important Number Might Not Be the Price

When most of us buy heating systems, the first number we ask for is the quotation.

Perhaps the first number should actually be:

“What is my house's design heat loss?”

Then:

“What flow temperature will you design for?”

Then:

“What seasonal efficiency do you expect?”

Only after that should we begin arguing about brands and purchase prices.

Because the question in 2026 is no longer:

Do heat pumps work?

Millions of systems have already answered that.

The important question is much more personal:

Will a heat pump work efficiently in my house?

And the only sensible way to answer that is not with ideology, advertising or internet arguments.

It is with measurements, engineering and a properly designed heating system.