Money Saving Boiler Challenge

This campaign focused on hot water heaters that provide water on demand for heating a home and also for cooking and cleaning. Lowering the water flow temperature from 80°C to 60°C could save a 9% reduction in total gas use, but only one in ten households had adjusted their water flow temperature in the previous year. Nesta developed and pilot tested an online tool to help occupants lower their own water flow temperatures. 

In 2022 and 2023, over 214,000 people used the online tool and indicated that they had turned down their water flow temperatures. Based on Nesta’s research, that would save around 200,304,000 kWh and £20 million on energy bills and would avoid the release of 37,000 tonnes of CO2 per year. The campaign created £33 of savings for every £1 spent on marketing.

Background

The water flow temperature is the water temperature at which a water heater circulates water to the radiators in a home. As concern has grown about climate change and energy efficiency, so has the recognition that setting a lower water flow temperature can reduce energy use and greenhouse gas emissions, and save money (Norm Appeals, Financial Incentives.)

Nesta is a charitable organization in the United Kingdom (UK). It is branded as “the UK's innovation agency for social good”, that “designs, tests and scales new solutions to society’s biggest problems, changing millions of lives for the better.”

Setting Objectives

The campaign's objective was for households in the United Kingdom using combi-boilers to turn down the water flow temperature of their homes' hot water heaters used for heating the house (boiler) to 60 degrees Centigrade.

Getting Informed

This campaign focused on combi boilers – hot water heaters that provide water on demand for heating a home and also for cooking and cleaning, as compared with those that have separate hot water cylinders for each use. Combi boilers were the most common type of boiler in the UK. And because they heated water on demand, there was no risk of Legionella bacteria growing from lowering the hot water temperatures to 60°C or below. A target of 60°C was chosen to provide a good balance between increased water heater efficiency, a practical warm-up time, and a strong likelihood of households meeting their heat demand whatever their situation or temperature preference. 

Most condensing boilers (the type of hot water heater mandated since 2005 in the UK) were set at a flow water temperature between 70 degrees Centigrade to 80 degrees Centigrade. Setting a lower flow water temperature would save energy and lower carbon emissions. It would also decrease wear and tear on the hot water heaters due to turning on and off less frequently. Nonetheless, some installers, manufacturers and energy advisors were reluctant to recommend turning down the water flow temperature. They were concerned about safety, level of difficulty, and the lack of evidence supporting effectiveness for existing homes.

Delivering the Program

Strengthening the Evidence

Nesta first worked to strengthen the evidence for reducing water flow temperatures. This involved reviewing existing evidence; conducting experiments with a test house; estimating the proportion of UK homes that could lower water flow temperature; and modelling the savings and room temperature impacts for different types of homes and heating preferences / occupancy profiles (Credible Communications.)

This research found that many households would not notice a difference in comfort from lowering the water flow temperature – just a 15-30 minute increase in the time required to reach the desired home temperature. Setting the heating system to start 15-30 minutes earlier than usual would lower the energy savings slightly but would still save energy and reduce carbon emissions.

Making it Easy to Do

Nesta developed and pilot tested an online tool to help occupants lower their own water flow temperatures (Overcoming Specific Barriers.) Early user testing with 46 people guided development of a prototype. Subsequent testing with 165 people who were representative of the UK population found that 77% would lower their water flow temperature as a result of using the tool. This testing also helped improve the tool.

Next, a randomized controlled trial with 3,400 users, found that 34% of those who received the tool had lowered their water flow temperature compared with 19% in the control group. These users rated ease and confidence at 4.8 and 4.3 out of 5. When asked about the likelihood of sharing the tool with friends and family, their average rating was 4.6 out of 5 (Word of Mouth.)

Developing a Brand and Communication Materials

In preparation for the campaign, Nesta created a brand for the campaign and tested alternative creative and messaging concepts (Vivid, Credible, Emppowering Communications) 

In addition to the online tool, Nesta produced a printable leaflet for households that might have trouble accessing the tool online. It also developed an online toolkit for advice givers.

Campaign Launch

Nesta launched the Money Saving Boiler Challenge in 2022. Its communication strategy had two main components.

1. One focused on communications with partner organizations. For example, the online toolkit for advice givers was targeted at them.

2. The other focused on the use of media, social media and paid marketing activity to contact households directly (Mass Media.)

Partnerships

Nesta’s briefings and research findings attracted high profile partners including energy companies and advice givers such as the following.

• Energy companies such as EDF promoted the campaign through emails and social media.
• UK Government Help for Household Campaign included Nesta as an advisor; Nesta’s water flow temperature tool was subsequently featured as that campaign’s top tip for households.
• National Residential Landlords Association
• Smart Energy Great Britain incorporated water flow temperature in its national energy conservation campaign, and in a national television ad.
• High Profile Influencers included television hosts, resulting in the campaign being featured in their shows.

The campaign reached out to and through energy saving groups and associations who promoted the campaign through their own channels (e.g. email newsletters, social media, Facebook groups, and workshops.) Housing associations promoted the tips to their tenants. To reach out to installers, who often serve as trusted advisors, the campaign ran a webinar in collaboration with Installer Magazine that drew 108 installers.

Unpaid Media

In all, the campaign attracted 198 spots in major UK media, such as the BBC, the Guardian and the Daily Telegraph. This was one of the campaign’s two most effective drivers for conversions in the fall of 2022, but effectiveness dropped off in early 2023. In addition, energy companies such as EDF promoted the campaign through emails and social media (Mass Media.) 

Paid Media

Paid advertising (e.g. on Meta and Google) was another of the campaign’s two most effective drivers for conversions in the fall of 2022. In early 2023, when free media activity had dropped off and most partner activities had ended, the campaign paid £550,000 for ads in social media, search engines, print, and radio. Paid media became the main driver for conversions. In all, paid ads reached 9.7 million households (68% of the target audience) (Mass Media.)

• Social media ads generated 41 million impressions, leading to more than 296,000 clicks to the campaign’s website.
• Google search generated 97,300 impressions, leading to 20,800 clicks to the campaign’s website.
• You Tube ads generated 43 million impressions. 30,900 of those views were by people who watched the entire video.
• Digital audio ads generated 7.8m impressions, leading to 7,100 clicks to the campaign’s website.
• Website ads generated 1.7 million impressions, leading to 2,000 clicks to the campaign’s website.
• One 25x4 ad in the Daily Mail reached over 2 million adults.

Overcoming Barriers

Barriers for Households

Barriers	How they were  addressed
·       Didn’t know they could change the water flow temperature ·       Inertia, other priorities	·       Promotional activities involving a range of media as well as high profile influencers (e.g. television personalities) and trusted advisors (e.g. energy companies, energy savings groups, government organizations, and the National Residential Landlords Association.)
·       Concerned about making a mistake	·       Online tool (plus a printable version) to help occupants lower their own water flow temperatures

Barriers for Engaging Installers, Manufacturers, and Advice Givers 

Barriers	How they were addressed
Concerns about safety, level of difficulty, and the lack of evidence supporting effectiveness for existing homes	·       Strengthened the evidence ·       Reviewed existing evidence. ·       Conducted experiments with a test house. ·       Estimated the proportion of UK homes that could lower water flow temperature; and modelled the savings and room temperature impacts for different types of homes and heating preferences / occupancy profiles. ·       Designed and pilot-tested a tool that made it easy for households to turn down the water flow temperature themselves
Insufficient background to be confident recommending the change in temperature	·       Online toolkit for advice givers

 

Measuring Achievements

The campaign hired an external campaign tracking agency to conduct pre-, mid- and post-campaign surveys with a representative sample of over 2,000 adults per survey.

In addition, those using the online tool ticked a box at step 8 indicating that they had turned down their water flow temperatures.

Results

Based on Nesta’s research, participating households saved an average of 936 kWh per year (£96) and avoided the release of 173kg CO2 emissions per year in 2022 and 2023.

The proportion of resident who said they had lowered their water flow temperature increased from 19% before the campaign to 29% after the campaign. 

In 2022 and 2023, over 214,000 people used the online tool and indicated that they had turned down their water flow temperatures. Based on Nesta’s research, that would save around 200,304,000 kWh and £20 million on energy bills per year, and would avoid the release of 37,000 tonnes of CO2 per year. 

Almost two in five people had seen or heard the campaign message. The proportion of residents who knew they could change the water flow temperature increased from 46% to 66%. 

The campaign had a potential return on investment (ROI) of 1 to 33. In other words, it created £33 of savings for every £1 spent on marketing.

Notes

Data Sources 

Money Saving Boiler Challenge: Supporting Evidence, October 2022. https://www.nesta.org.uk/report/money-saving-boiler-challenge-supporting-evidence-october-2022/

Money Saving Boiler Challenge: Campaign Evaluation. https://media.nesta.org.uk/documents/MSBC_Evaluation_for_website.pptx.pdf