The $120 million Busselton Hospital is riddled with building faults and is still a construction site almost two years after it opened, a union claims, but the WA premier insists there is "no issue" with the facility.

United Voice says ceiling faults have forced the closure of the facility’s kitchen, meaning meals will be prepared out of a food truck in the hospital car park and walked through a back entrance into the hospital.

WA assistant secretary Pat O’Donnell said the “horde of problems” with the hospital had been brought to the public’s attention in July and the lingering issue was a grave concern to workers.

“At the time, the head of the WA Country Health Service said the works would be completed during a 10-week period over Christmas. Now they believe it will take until May or June,” he said.

“This hospital shouldn’t have opened until all these construction issues were resolved.”

But WA Premier Colin Barnett insisted there was not a major problem with the hospital.

“There were some problems, particularly in the ceilings, so those ceilings have been repaired,” he told reporters on Sunday.

“At the moment work is going on in the ceiling of the kitchen, so obviously the kitchen can’t be used for preparing meals, so the meals have been done outside and through transportable cooking facilities.

“There is no issue. The hospital is continuing to operate as normal.”