Eight fire engines arrived at the city-centre hotel at 5pm last Thursday following reports of a fire on the fifth floor where renovation work was being undertaken. It is not yet known how the fire started.
All guests and staff were evacuated from the Grade II Listed building and no-one was injured during the incident, but firefighters spent several hours at the scene damping down areas and using thermal imaging cameras to ensure no pockets of fire were contained anywhere.
Merseyside Fire & Rescue Service area manager Dave Mottram said: "Our firefighters reacted quickly to this incident which proved difficult to tackle due to the location of the fire.
“Firefighters worked fast to limit the damage but it has taken some time to make sure the fire has not spread through any voids between walls and in roof spaces of the fifth floor.
“No-one was injured in the fire and there were no rescues. Fire alarms were activated, an evacuation was carried out and everyone left the building safely. An investigation is under way into the cause of the fire."
The Beatles-inspired hotel shut for 24 hours after the start of the fire, but following advice from the fire service, Hard Days Night general manager Mike Dewey decided to re-open its restaurant - Blakes, its bar, called Bar Four and the hotel's lounge on Saturday as well as host events planned for the weekend in its function rooms and suites.
However he and his management team made the decision to keep bedrooms on all floors shut until the situation had been reassessed, meaning staff had to relocate guests elsewhere or cancel bookings, losing trade over the busy Valentine's weekend.
Dewey said: "Merseyside Fire and Rescue Service have finished their investigations and we are pleased that we can reopen parts of the hotel. They did a fantastic job in confining the fire to the right hand corner of the hotel on both the fourth and fifth floor and I cannot praise them enough.
"At this point, we have no further information but the team and I would like to thank everyone for their continued support and understanding at this time."
Hard Days Night Hotel opened in 2008 in Liverpool city centre's historic Beatles quarter. It features suites named after members of the band and houses artwork by world-renowned Beatles artists such as Klaus Voorman and Shannon.