Fix a Broken Furnace With Arduino

The control board in my furnace will not turn it on unless I manually turn the blower on. But when I do that the blower stays on until I manually shut it off.. So I built this to turn the blower on and off and also to override the thermostat.

I built this a while back out of necessity. I have not intended to make it an instructable so I did not do a step by step build. If you have any questions, please feel free to let me know, this is my first instructable.

First we need to collect some parts.

NPN Mosfet - FQP30N06L - $0.95

Solid State Relay SSR-25DA $2.55

Transistor PN2222 $1.95

Arduino UNO $24.95

3 X 100 ohm Resistors $1.49

Relay $1.28

Temperature Sensor - TMP36 $1.50

Just shut off your thermostat and hook this up and you are good to go.

If you have any questions of comments let me know