Introduction -- Models of Models: Filtering and Bias Rings in Depiction of Knowledge Structures and Their Implications for Design -- The Quick Association Check (QuACk): A Resource-Light, 'Bias Robust' Method for Exploring the Relationship betweeb Mental Models and Behaviour Patterns with Home-Heating Systems -- Case Studies of Mental Models in Home Heat Control: Searching for Feedback, Valve, Timer and Switch Theories -- When Energy-Saving Advice Leads to More, Rather Than Less, Consumption -- Mind the Gap: A Case Study of the Gulf of Evaluation and Execution of Home-Heating Systems -- Using Interface Design to Promote a Compatible User Mental Model of Home Heating and Pilot of Experiment to Test the Resulting Design -- Mental Model Interface Design : Putting Users in Control of Their Home-Heating Systems -- Conclusion