My heater doesn't blow air to the floor, only blows to the defrost vent and dash. Is this vacume leak or climate control problem?

Usually related to loss of vacuum in system or vacuum leak in footwell diaphram.

Thanks. How do you check for the leak?

The switch valve that operates the system is to the left of the glove box(liner removed). The vacuum supply line is green/yellow tracer(15-20" of vacuum w/engine running)). The vacuum line to the footwells is a red/yellow vacuum line at valve # 3.