incubator problems

hello my first post on this site so here goes i have an r com 20 pro (usb version) incubator had it about 2-3 years and my problem is it keeps flooding the resivour in to the incubator cant figure out why any one who could help would be greatly appretiated as i have buff orpingtons in tere at the moe and dont whant them to spoil cheers john