Worrying slowdown in the sales Heat Pumps in 2026

FreeBear

It makes absolutely no sense why would you want 70° water circulating through radiators from any kind of wet heater? Never mind the stress on the compressor. Even gas doesn't heat the leaving water that high. Your rads would be dangerous to touch.

Unfortunately, there are a lot of gas engineers out there that will install heating systems using 70°C flow temperatures. Or they may be lazy in commissioning the system and leave everything on default settings - When I had my boiler installed, the installer left the boiler with a flow temperature of 70°C, DHW at 60°C, and pump speed at 100%. Absolutely no attempt to adjust the setting to match the rest of the heating system.

Have since dialled back the temperatures and adjusted most of the parameters after wading through the installation manual. Current flow temperature(s) is in the ballpark for a heat pump, but a couple of radiators could benefit from being a little larger.

QrizB

It's highly unlikely to lower running costs…

Indeed.

Vaillant doesn't seem to publish a SCOP for a system with a 70C flow temperature, but it does publish SCOPs for 35C and 55C.

For the 5kW model, at 35C it has a SCOP of 5.01 and at 55C it's 3.70. The 7kW and 11kW models both have slightly lower SCOPs.

Looking at those numbers, at 70C the SCOP will be rather less than 3 and possibly somewhere around 2.

Based on my calculations from 18 months ago, it would be worth the average household spending £4-5k on replacement radiators, plumbing etc. to decrease the flow temperature from 70C to 55C and improve the COP.

NedS

I agree that sticking a heat pump on an existing system with high flow temps, and hoping for the best is probably not the best strategy. I get many people do not want the disruption, but they are never going to get the best out of a heat pump at those high flow temperatures.

We replaced all of our radiators and went with the largest size that each room could reasonably accommodate in the space available. It was mostly subtle - going from a 1400x600 to 1600x700 K2, and we added one additional radiator in the room that was hardest to heat. The result is that we run 32C flow temperature for most of the year and have a SCOP of 4.3 since the system was installed.

For reference, 12 assorted K2 Stelrad radiators came in at £2k when we installed our system 2 years ago, it is cheaper if you are able to go with standard sized radiators (a 1600x600 is cheaper than a 1400x700 although they have similar outputs)

greenbee

I changed/added radiators as I renovated, so when I came to the heat pump installation most of the rooms were heat pump ready. One of the surveys suggested changing a lot of the radiators, so I ended up going with the more pragmatic installer who said that although a couple of rooms were borderline, they do have supplementary heating (electric towel rails, multi-fuel stove), so we should do the installation and if any rooms are too cold we can change the radiators when we identify the problem. Of course, i haven’t needed to put the heating on since then (although it may well go on next week unless agile prices stay negative so I use electric heating instead to maximise the benefit). But it was a good way to deal with it if the disruption is putting people off.

I now need to work out the radiators for the kitchen, as it’s about to come out so we can finally get round to getting the heating right in there as it had always been cold!

NedS

https://forums.moneysavingexpert.com/discussion/comment/82164104#Comment_82164104

Yes, I get that it can be difficult for a lot of people.

I have a friend who is on oil and costing him an absolute fortune at the moment. He has seen our success with a heat pump and would absolutely love to make the switch, but his kitchen is a real issue. The kitchen was extended and is the hub of the house and was completely redone only a few years ago. There is nowhere to fit decently sized radiators that would be needed to heat the space with low temperature heating, and there's no way he's going to rip it all out for underfloor heating, so it's really holding him back. He's currently investigating fan coil units to go under the kitchen cabinets, but it highlights some of the practicalities involved. It's easy to fit big radiators if you have the wall space to fit them, but not everyone does.

QrizB

He's currently investigating fan coil units to go under the kitchen cabinet

I was going to suggest plinth heaters, but it sounds like he's already on the case.

The_Green_Hornet

If this report in The Guardian is true then expect the slowdown to increase to a crawl.

https://www.theguardian.com/environment/2026/oct/12/ministers-plan-slash-heat-pump-subsidies-fund-defence-spending

Magnitio

https://forums.moneysavingexpert.com/discussion/comment/82165864#Comment_82165864

Maybe they should increase the tax on gas and oil boilers.

silverwhistle

I think they may be allowing for natural market forces to do their work!

On the subject of kitchen heating it very much depends on size and layout; mine being a small galley kitchen with adjoining dining room through an open doorway. The kitchen has never had heating and in my circumstances doesn't warrant it as it's a place where I'm active with heat from the oven, sink, refrigeration to help.

I'm going to go for an A2A two way split and fairly low powered at that, as I'm in a mild climate, decently insulated and snuggly mid-terrace!To be honest the upstairs one will be more for summer air-conditioning. One winter season to check how it works and then getting rid of the gas meter. I used 19kWh last March and none (bar a test) since then so I'm reasonably optimistic.

stripling

@silverwhistle

I think they may be allowing for natural market forces to do their work!

Except there's no such thing as 'natural market forces' - markets are controlled by taxes, regulations, 'incentives', subsidies, tariffs and so on. The business subsidies are eye watering.

From the beginning of nationwide energy - the first coal even - the so-called market was subsidised.

If they really do cut the BUS grant it will be an outrage and victim to lobbying and myth-making about 'subsidising the middle class'.

We need to decarbonise and we need to do it fast. The BUS grant is a grant per house not per person. Every heat pump installed is another house decarbonised because you are not allowed to re-install gas heating. We should've outlawed new gas installations years ago.

Lots of people (me included) get loans to pay for their heat pumps and without the BUS the repayments become unaffordable. There was the ECO system that installed heat pumps for free for the low waged but that has become ever more restrictive. Even when it did exist lots of people couldn't access it because installers wanted bulk jobs not one offs. By cutting BUS only the very well off will be able to afford a heat pump. This is so retrogressive it's ridiculous.

Every other European country has grants for heat pumps. Many have them for solar or batteries too. We are so far behind the rest of western/northern Europe. I was in Sweden and Denmark recently and most of the taxis are EVs, all the public transport etc,, everywhere I stayed in Sweden the homes were heated by heat pumps.

Rather like EVs which we are now seeing on the used car markets at affordable prices. There was the same whining about EV grants a few years back - 'subsidising the middle class lifestyle'. Subsidies and grants pay off over many years - rather like the £3000 EVs on the used car market - opening up access to those of us who operate on a shoe string. We needed the buyers with money to get where we are now.

If the BUS heat pump grant gets axed it will be a disaster - we really need to challenge these stupid 'middle class' stereotypes.

Business investors want clear policies and directions and this sends dreadful chaotic signals about Britain.