Replaced fan on G20re furnace late summer.Thermostat was clicking on and off, replaced thermostat, now fan is only kicking on intermittently. Have hit the unit couple if times and it will kick on. Loose wire?

Loos wire it could be. Also a defective fan control or relay.

Dope-slaps only work on people, not HVAC equipment. :)

What are you hitting: the tstat or air handler?

Dope-slaps only work on people, not HVAC equipment. :)

If only that were true :p.

Can't even begin to count how many low pressure controls or fan cycle switches I have had to influence with a little whap from my linemans.