The room I worry about is my daughter's room, it's the last rad on the circuit and can be noticeably colder.
You need to balance your radiators. Close the lockshield a bit on the ones that are warming up quickly and open it up on the ones that don't. Takes hours to do it properly. Some people like to measure the input and output temperature of each radiator with a thermocouple while doing it. Heating engineers will never do it properly because it takes far to long for anyone to want to pay for their time to mostly drink a lot of tea.
Yes. This has been a thing. I thought I had them sorted this season of "turn the heating on!".
Now it's "get the fucking boiler working" episode in the season.
You need to balance your radiators. Close the lockshield a bit on the ones that are warming up quickly and open it up on the ones that don't. Takes hours to do it properly. Some people like to measure the input and output temperature of each radiator with a thermocouple while doing it. Heating engineers will never do it properly because it takes far to long for anyone to want to pay for their time to mostly drink a lot of tea.