The Boiler Upgrade Scheme

“Air source heat pumps- The real conversation.
Let’s be honest….
Installing an air source heat pump system when an existing gas boiler needs replacing will help save the planet, but it won’t (currently) save the resident money on utility bills.
Saving on energy bills seems to be one of the biggest misconceptions that Residents have when choosing to switch to ASHP systems.
People get confused by the perfectly correct claim that ASHP systems are approx 300% efficient . i.e you can get out 3 to 4 times as much energy as is needed to drive the system.
However, in reality, if going from gas fired boiler central heating to ASHP then expect to pay up to double the overall annual cost compared with the gas annual heating bill. Why?
According to much of what I can find online in regard to heat pumps, the average person’s carbon footprint will be reduced by 42% when replacing their gas boiler with a heat pump system.
That appears to be based the premise that because of the “free” energy obtained and also because electric are systems are generally a bit more efficient than a gas boiler (say 90% efficiency of a condensing gas boiler).
What people seem to miss is that the cost of electricity per kW is 3 times higher than per kW of gas!
ASHP systems drawing their air intake from outside can increase the (water) temperature circulating through radiators by up to 4 times the outside temperature. However, realistically the circulating water needs to be raised to 40 degrees C to provide meaningful heat output into your home from the radiators or underfloor system.
Once outside air temperatures dip below 10 degrees C (so when you need your heating) then 40 degrees C circulating water temperature cannot be achieved from the system and the resident will be forced to supplement this with mains grid supplied electricity to boost the water temp up to 40 degrees C, unless of course they accept to live with much lower room temperatures.
So….the likely hood is that they’ll be using/paying for just 58% of the kW energy from the grid (compared with gas) to heat the property.
However, generally speaking
1 kW of supplied electricity costs just over 3 times as much as 1 Kw of gas (currently 34p compared with 10p).
If getting 42% of your heating for free that means you are buying the remaining 58% from the grid unless you also have solar panels which cost additional to buy and install, and only provide around 1.2kW in total on sunny days. (By the way, there is nothing to stop you having a gas boiler and still fit solar panels to reduce the gas used toward heating your hot water cylinder, or to drive your lights, assuming you have the storage battery option.)
58% at 34p per kW compared to 110% of gas needed to do the same job, but only costing 10p per kW.
Residents will use less energy but actually be paying more overall.
In detail that equates to 19.72p (58% ) of mains electricity energy usage compared with 100% of gas at 10.4 p.
So switching from a condensing gas boiler Residents will likely be paying about twice as much overall for their heating, but will actually be using much less energy and have a lower carbon footprint, so helping to save the planet.
If we are serious, why not simply apply a
Government levy increasing the price of gas per kW by 10p to 20p per kW and use that additional 10p revenue to discount electricity per kW down to 24p so that the cost per KW used turns out to be the similar for either system. That way the sensible choice going forward would be for residents to install ASHP instead of Gas boilers.
This could make it worth suffering the higher installation cost, but be kinder to the planet?
A basic ASHP system for an average dwelling costs approx £8500- That does not include the larger surface area radiators and new piping required (plus re-decoration) or underfloor heating pipes being installed.
A replacement Condensing gas boiler (installed) is approx £3000- to £3500-
The government boiler replacement grant of £5000- would then really make the switch to ASHP far more appealing, although you still need to replace the radiators.
Alternatively, buy and install Radfan Extra Boost…
The Extra Boost model has more fans per unit to facilitate a higher airflow, providing as much help as possible to get the available heat out from existing radiators. This provides residents consideration to the cost saving option of not replacing their existing radiators when installing ASHP systems.
Write to Amanda Robinson
In our Proven Energy Savings section you will see that Radfan has been extensively trialled and tested in labs and real world homes to make sure that the Radfan helps customers feel warmer and reduces their energy bills.

On our Instructions page you will find how easy it is for customers to set up the Radfan on their radiators and plug into a standard UK power socket – please note that this product is only technically suitable for use in the UK and should not be sold for use outside of the UK.

We do not sell directly to the general public as Radfan Ltd is a business-to-business manufacturer/supplier – if you would like to become a retailer please use the contact email.

​If you would like to buy Radfans for your home then please see our purchase page and follow the links provided.