Probably the flame sensor.
It could be a thermocoupler, happened to my furnace in middle of night a few years ago.
Turn up the inlet gas pressure on the furnace to create more BTUs.
What do you mean by "has no heat"? No air blowing out, blowing out cold air when heater is on, blowing nothing at all? Heater not turning on? What specifically is happening?
No one knows if:The heater is NOT blowing - or blowing on high speed only, or... The heater IS blowing, but the air is NOT hotEither way, the "Related Questions" below will get you started
Not if it was disconnected properly
if your heater just went out in your house and you need a really good electrical furnace you should really consider getting a whole new furnace from a hardware store or a heater store.
heater, boiler, oven
Furnace, woodstove, heater
Good question.A furnace is a enclosure in which energy in non thermal form (e.g. a fuel) is converted into heat. The inside of the enclosure becomes an intensely hot place.A heater is an apparatus that heats or provides heat.In refineries, the terms "furnace" and "heater" are used interchangeably, sometimes with the word "fired" in front of heater.
heater fan only works after about 15 minutes on my 89 plate range rover
Furnaces have no RPM ratings
i would suggest putting a new thermistat in. it only takes about 30 minutes to do and the part is cheap