Furnace blower will not shut off

ahh any chancesomeone set the thermostat to fan always on

any chance someone set the thermostat to fan always on?

some friends called me our furnace is running forever......

I went over and moved the switch

And if that's not it, next I'd find and disconnect the thermostat fan wire at the furnace. Eliminates the possibility that it's a bad thermostat, short in the wires to the thermostat, etc.

Next would be that it's a bad control board. Don't know how old that furnace is, what technology it uses, etc.

Hi, Sounds like you have error situation like high limit sensor triggered. Did you turn the furnace off/on? Did the blower stop?

On 16 Jan 2015, trader_4 wrote in alt.home.repair:

I just last week went through this exercise for the same symptom, the blower ran constantly. I had hoped it was DIY fix, but these newfangled furnaces are extensively computer controlled, and there are few easy- and-cheap-to-replace parts like relays. It turned out that the furnace's motherboard had partially failed and had to be replaced. It's working fine now.