hello ,i recently purchased a sundance optima 880,it is a 2007.i am having issues with my air blower,it seems to be working(moving air) but no bubbles are coming out(one of the jets mite get a trickle of air once in a while).the other symptom is at times it makes a sound almost like someone blowing through a tuba or something similiar(my thought would be a blockage),now if i hook up my shop vac reverse through the aromatheorpy hole i can get bubbles out of all the jets,so if it was an obstruction i would have thought it was blown out by now,so could the blower motor be weak,im not sure how it is plumbed ,if there is one check valve or if each individual jet has a check valve,could the motor be weak enough not to open the check valve,like i said im not sure of the basics of the plumbing im only assuming,thanks in advance