02 taurus no heat

That year has a odd Y pipe configuration that is prone to getting clogged up because of a bypass hose set up. If your blend door is working o.k. and the thermostat is good I assume you checked that already. If not do so. If all that checks out I'd try a heater core flush. Some people have done modifications to the Y pipe bypass due to not having heat problems. If it was mine I'd try the flush first if all else checks out. Good Luck!