My heat is on but not blowing out through the vents. I've gone down to check to make sure the pilot light is still lit which it is. The plumbing for the unit is hot in the basement I hear it kick on but nothing is coming up through the vents? What could be the problem?
Have you checked to be sure that the blower fan is working? Just because the furnace kits on and heats does not mean the fan is also coming on and moving the heated air. Also check to be sure all vent louvers have been opened and none are left shut from being closed last Spring.
Check the power switch or fuse - a forced air heater has a blower motor - there is often an electrical switch (sometimes there is a RED switch plate on it) stating it is for heat and do not turn off. The pilot is on, and the fuel is controlled by a valve that may be independent. If all seems ot go on except the blower motor, that may need to be replaced.
The other answers nailed it. The furnace blower is probably not coming on. Turn the fan switch on the Thermostat to ON and see if the fan turns on. If it does NOT come on them most likely the blower motor has failed or the capacitor that helps the motor start spinning has failed. If the fan will run only with the switch on ON then the fan control( a temperature controlled switch in the heat exchanger inside the furnace) may have failed. Good luck
