Excellent service from the British Gas engineer this morning – he arrived promptly, checked the system over and repressurized it – that cured the immediate problem. And, because it only took a minute, he’s going to show the visit on his records as “customer not at home” so that I won’t be charged (phew! £96 saved). However, he did diagnose a problem with the printed circuit board – he said it’s probably just a dirty connection, but that if it got worse, the PCB would need to be replaced, which would cost £250. I said I could live with it for now, which was exactly what he recommended me to say!