I have a Lennox electric furnace that's about 10 years old or so, the elements come on but no blower. There is a summer fan switch that will make the blower run when switched on, but it will not come on with a call for heat. Also at my work, there is a york gas pack that is probably 15 years old. The blower runs all the time even if I disconnect the wire from the t- stat and the gas pack. Any suggestions on either problem?

On the Lennox I would check for a defective blower relay or the blower might be controlled by a heat sequencer.

On the gas pack you need to check the blower relay circuit. I would start by disconnecting the thermostat wires at the unit. This is done to check for shorts in the wire itself. If the blower still runs then it is in the unit itself.

I have a trane that the blower for the chimney keeps running , even after the call for heat any ideas?