In the Midlands, programmer Tomás McGuinness has designed a different gizmo that uses sensors to read the flow temperatures on his boiler. It sends a notification to a smartphone app if the return flow rises above 55C, the approximate point at which the boiler would stop condensing. He can then fine-tune the temperature manually.

“My little sensor system, I could probably put it together for about a tenner,” he says. Via Twitter, he’s found several people who are willing to try prototypes of his device, which he says he might go on to produce for sale.

This and other measures, such as reducing his boiler’s power consumption and insulating his home, have helped him take control of his energy expenditure, he adds.

However, Mr McGuinness says he is still concerned about the continuing rise in bills.

Mr Pschierer-Barnfather agrees, adding that he feels “lucky” to have the skills required to reduce his gas bill slightly. He argues that fellow techies are in a position to help others shield themselves from energy price rises.

“For people who haven’t got double glazing or haven’t been able to do what I have with their boiler, they’re going to get the full whack of this.

“We can help. We’re a slightly geeky minority… I feel that there’s more that we can do.”

More efficient boilers should be the norm, he says.