Thanks BL - sounds like this one's above my pay-grade. I'll put in a call to the Vaillant guys as I'm covered for the year after last week's fiasco. It's odd that the problem only arose after the engineer checked it over - makes me think it isn't a hardware problem, but I'll let you know what he...
Hi guys,
We recently had our boiler repaired as a previous owner left one of the valves open and the pressure was constantly rising. The repair-man closed the valves and now pressure is stable at 1-2 bar. But ever since, the boiler has been failing to remain hot when running the tap / shower...