I have an Armstrong air techV 80 unit. I tried to turn on the heater the other day and it didn't work at all. The air had been working fine all summer. I replaced the smart valve thinking that would solve the problem. Well, now the heater works but even when the theromostat is OFF the inducer motor randomly kicks on for a couple of seconds then turns off ALL DAY LONG. NOW WHAT?

What makes you think its caused by the smart valve? Does it send the signal to the different parts?
Does your unit have a circuit control board? If so what does it control?

Well, It wasn't working at all and then we put in the new smart valve and it kept turning on even when the thermostat was off. We replaced the control board thinking that was also bad. It didn't help. We have two heating units in our house so last resort was to swap the smart valves and see if it worked on the other unit. Now, the first unit has the old smart valve and is working fine. The second unit is doing the same thing, turning on by itself. That is why we think it is the smart valve.