Thanks, that’s really helpful.
Tonight we’ll use the override button to see if the heating comes on straight away. That would be useful to know as it gets colder. We’ll have to read the remote thermostat instructions to figure out how that is currently set up.
I reckon that if the left button...
Having moved to a new property in June, the Navien NCB300-28K boiler has only been used for the hot water. Last night we decided to test the radiators so, following the (basic) manual, I did the 5 second M and + button push which brought up a number (5 Switched Live, I think)
The other options...