PHAM NEWS | FEBRUARY 2025 DomesticBoilers 27


Time out for less effi cient boilers?


The government has issued a number of proposals designed to raise the effi ciency of domestic heating systems, which could see the removal of some lower performing products from the market. Martyn Bridges from Worcester Bosch provides an overview of some of the latest consultations and the issues they hope to address.


raft of new consultations. One publication, with a total of 97 questions, landed in December – off ering a lengthy review of heat pumps, hybrids, gas and oil boilers, and controls in the UK. Here are some of my takeaways.


A


Enhancing effi ciency The latest consultation, raising product standards for space heating, intends to improve boiler standards and effi ciencies. While it contains several proposals for new energy standards, I see it more as a searching consultation, exploring the feasibility of suggestions rather than fi rm indications of what the government is intending to implement. Several headline proposals


list minimum performance standards for the effi ciency of heating products in the UK – particularly heat pumps. While some of these are achievable, others might not be. Yet, around half of the consultation is focussed on the installation of domestic gas and oil-fi red boilers and controls.


Achievable goals One recommendation suggests that all gas-fi red combination boilers must be manufactured with the ability to modulate down to 15% of their maximum output. Generally, most combi boilers have an output around the 30kW mark. In this case, they will need to modulate down to 15% of that output – equating to 4.5kW. It’s a fairly sensible proposal, as few heating systems in


Martyn Bridges Director of external affairs at Worcester Bosch


BY NUMBERS


15% 30% 1.5m 2026


s the new government shifts into gear, the heating industry is expecting a


the UK reach anywhere near the 30kW output of a combi boiler. So, modulating this down to a more realistic level for domestic heating systems should prevent the boiler from cycling – maintaining effi ciency and saving money for the consumer.


It is proposed that all gas-fi red combi boilers should be able to modulate down to 15% max output


Oil boiler challenges There are also calls for oil- fi red combination boilers to modulate down to 30% of their maximum output. This would be considerably more diffi cult to achieve as modulating oil burners are not prevalent in the UK market. There is one available appliance we believe can achieve this but it doesn’t resemble the normal appearance of an oil-fi red boiler. If the requirement is


there are calls for oil-fi red combi boilers to modulate down to 30% of their maximum output


maintained, a compromise may have to be reached where oil-fi red boilers modulate down to a higher minimum rate than the 30% currently proposed. It may also be a staged burner that fi res at full output, and perhaps 70% of its output, to achieve any downturn at all.


There aren’t enough building control offi cers to check the 1.5m boilers installed each year


One recommendation says that all boilers must use open protocols by mid-2026


Move to modulation One proposal outlines the removal of class one to three controls from the market by 2026. This category includes on-off room thermostats and weather compensation controls for use with modulated heaters, on-off heaters, or boilers. Removing weather


compensation controls from the market could be seen as a backward step, as it’s arguably the most effi cient way of controlling a domestic heating system. Ultimately, responses to


these proposals will dictate which route the government takes. There’s a clear desire to remove on-off switching in boilers, with the government preferring to adjust temperature output and modulation rates. Also, on-off thermostats


would still be needed for certain applications such as heat interface units, zoned heating systems, etc.


Building regulations Some would argue that trying to do everything with a product is not necessarily the right approach, particularly when building regulations are in place to ensure installation standards are achieved. It might be a better place to


state where and when an on-off room thermostat or a weather sensor can be used rather than remove them from the market altogether. But of course, there is little to no policing of an installation once it’s happened, with most installers opting to self-certify. There simply aren’t enough


building control offi cers to check the 1.5 million boilers installed each year. Therefore, the government is using a competent person scheme to allow installers to self-certify their installations.


Timeline for change Finally, one recommendation says that all boilers must use open protocols by mid-2026. While it’s technically possible, I believe the tight deadline could pose a challenge – with fewer than 18 months to research, design, and test a new circuit board, many manufacturers simply won’t have enough time. In fact, it’s most likely the proposals in the consultation won’t be agreed upon and implemented much before the end of this year, leaving an even tighter deadline to the proposed implementation date. Currently, many combination


boilers have closed protocols that only the manufacturer’s controls can connect to. The desire to move to an open protocol should act as an initiative to increase the competitiveness of all other controls on the market and not limit boiler sales to boiler manufacturers’ control systems. However, it is unlikely that open controls provided by any control manufacturer would off er the functionality and additional benefi ts that the appliance manufacturer’s controls can.


Slow process Some of these proposals will test manufacturers. Others are certainly achievable. The timelines, however, will need negotiating – it’s a slow process to design such a vital product that is robust and reliable enough to not let the consumer down. ◼ phamnews.co.uk/225/46


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40