Oil furnace fan limit switch/thermostat info request

[JCJ]

I have recently installed a pellet stove and have the need to circulate the warm air around my house using the furnace fan.

I changed out my thermostat to one with the fan only option but upon tracing the wires down to the furnace the 3rd (and 4th) wires are not attached as the limit switch doesn't appear to have that option.

I'm looking for some guidance on specking out an appropriate switch and any install advice. Or if I'm even on the right track..

Thanks in advance..

[Strideraa]

You're on the right track but it is best for you to use someone experienced in working on hvac to make the changes. Wiring it wrong could burn up your motor and be much more expensive than a tech.