Hotel manager Adam Isbester said the flooding was caused by a burst fire protection system main.

"It flooded the front bar and the bar upstairs," Mr Isbester said.

"We got everyone out just to be safe."

Emergency services were called to the scene at 6.34pm following the triple zero phone call for help.

"The crew was up here for a couple of hours, they were really good the State Emergency Service and the fire brigade came and helped," Mr Isbester said.

"They are a bit unsung those emergency services."

Fire and Rescue NSW Orange Station Officer Matt Jeffery said 15 to 20 guests who were staying at the hotel, as well as those in the bar, were evacuated.

"It occurred [water leak] in the ceiling space between the second and third level, and we had flooding at the second level and ground level," he said.

"The hotel stopped trading and the hotel guests had to evacuate for about three hours.

"Our priority was to get the hotel areas safe for the guests to return for the night."

Water had pooled on the ground floor in the public bar and was also running through the ceiling and light fittings.

"The power was turned off, but we were able to keep the fridges running," Station Officer Jeffery said.

"We had three trucks there and we used a water vacuum cleaner and we had a need for a second one so we called the SES for backup.

"Fortunately there wasn't much [water] at all in the individual guest rooms, it was more in the common areas."

A plumber and electrician were called to the scene.

Station Officer Jeffery said the cause of the leak is still under investigation.