old 1989 classic model, refilled it, heats up, when jets turned on they just make a noise like they want to come on but don't. Any ideas apprteciated.

Mine did that when I first filled it, it had air in the lines. Put your hose in the filter and pump the water through from there. I also had to put my hose on each jet, and on the intake to force the air out.

pump probably air bound as suggested. Loosen either union at front or top of pump until water comes out. Or loosen stainless steel band clamp around outside of jet pump. If it still doesn't pump, impellor could be broken.