Had service out yesterday to work on the furnace. No heat, trouble light said "Pressure Switch Stuck Open." He replaced the pressure switch and also fixed some wires leading to it that had bizarrely got charred. (Not near the burner, not near a furnace panel, very strange.) In any case, it's still not working right. Power cycling the unit from the breaker panel seems to clear the condition (until it happens again.) Control board? Ghosts? Voodoo curse?
Also, is there some kind of guarantee policy on HVAC service work? Do I get a credit on the original 1hr labor charge for the 2nd visit, or what?