No heating since last night. It was the credit shortage and the zero-pressure problem.
Couldn't re-pressurize it until the landlord came, but he couldn't figure it out why it failed to work after pressurizing the boiler. I kept trying with my friends' remote help and finally spotted the problem that the credit wasn't automatically added on. Finally I got through after quite a few attempts. Patience paid off.
Leaving for Sheffield via Manchester early tomorrow morning. So no longer worry about Emily since heating is now restored.