Boiler retirement: Using trigger points to support homeowners to plan for energy upgrades.

Executive summary

Over the coming years, increasing numbers of UK homeowners are expected to change from gas and oil heating systems to electric heating, such as a heat pump. This involves complex and costly decisions for homeowners who have to consider the changes that might be required to install a new heating system, as well as other upgrades such as solar panels and batteries. 

Trigger points identify the times when these changes are more likely to be convenient and cost effective, and homeowners are more likely to be open to considering them. Examples include when an old boiler needs replacing, when a homeowner is planning a home improvement project, and moving home. Providing homeowners with prompts to consider home energy improvements at these times, and information and advice to support their decisions, can help them to make more timely and informed decisions.

This report brings together the findings from a project Which? ran in 2025 and 2026 that included research to understand homeowners’ behaviour around boiler replacements, the messages that are most effective in engaging homeowners, two communications campaigns and discussions with stakeholders.

Lessons for communicating with homeowners

We tested different messages to see which would be most effective at engaging homeowners to plan ahead for replacing their boiler and ran our own communication campaign in Autumn 2025 to see what lessons could be drawn. We then conducted a further communication campaign in the Spring when homeowners often consider home improvements to further test and build on the lessons learnt. Based on these examples we found:

• The right messaging can significantly increase engagement. Our testing of different messages around boiler replacement showed that the optimal set of three messages could deliver 87% engagement.
• The results of our campaign suggest that keeping the imagery simple and related to the topic (i.e showing a boiler or heat pump) and highlighting the benefits of heating upgrades generated higher engagement.
• The response when we included the campaign in our newsletters was very good. This suggests that communications with homeowners that have already expressed an interest in an issue and where the homeowner has an existing relationship with an organisation delivers high engagement.
• Providing a clear action is also important. Our spring campaign linked through to our Home Energy Planning Service that guided consumers through their choices and provided the option of practical advice more tailored to their property and needs.

From campaign led change to systemic change

As well as running communication campaigns, there is an opportunity for governments and businesses to adopt a more systemic approach that uses trigger points to prompt and support homeowners to consider home energy improvements.

Our final chapter includes proposals from across the sector for how this could be done, including using data from the Gas Safe register to identify trigger points, utilising the engagement that companies have with homeowners when servicing their boiler, and proposals to link incentives to trigger points such as home buying to encourage homeowners to consider energy improvements.

Recommendations

Governments, businesses and organisations in the home energy sectors have an opportunity to use trigger points to support consumers in the transition to electrification by providing them with prompts and information at times when energy upgrades may be more convenient and cost effective. Changing to electric heating at that point in time may not be the right option for all households, but having time to consider their options, and access to good quality information and advice, will support them in making an informed choice.

Replacing an older boiler and Spring home improvements are two important trigger points, but they are not the only opportunities to engage homeowners that may be considering home energy improvements. Planning a home improvement project and moving home are other times when homeowners are more likely to consider changes.

• Governments and businesses should develop strategies for how they will use trigger points, through communication campaigns or more systemic changes, to engage and support homeowners so that they are aware of the home energy improvements they could make and have the information and advice to make informed choices.

Trigger point strategies should:

• use data to identify when homeowners may be at a trigger point. This could include information about the age of their heating system, if they are applying for permission to make changes to their home, or if they are moving home. Data can also be used to better understand homeowners behaviour around trigger points. This data may beheld by public bodies or businesses.
• create partnerships with the businesses and organisations that engage with consumers at these times so the information and advice is available when and where consumers need it. This could include energy providers for boiler replacements, DIY stores for home improvement projects, or estate agents and surveyors for moving home
• build on the findings from existing home energy campaigns run by governments, businesses and organisations to develop effective messaging.
• work with organisations that homeowners trust, as homeowners are more likely to engage with advice from these organisations.
• provide easy access to good quality information and advice that is tailored to the property and the householders needs.