Even with the built in programmer?
To the OP press the left hand button on the programmer that says select once this should stop it.
And as I said the receiver is built into that programmer on the front of the boiler.
I turned off the water using the left hand button (so indicator pointing to OFF) and it doesn’t seem to have made any difference. Boiler still making noise and temperature still showing around 50C. I turned it it to ON and then OFF again and interestingly it turned off the ECO light when it’s ON and it turns off the ECO light when it’s OFF which would match with what you were saying about how it’s this programmer that controls the pre-heat. I’m still getting hot water when it’s OFF as expected. Any other ideas?