REZNOR FE 50 problem

[zfast]

I have a reznor fe 50 gas in my garauge. The problem i have is
some times but not all the time The blower fan will cycle on and off after a little bit it will stay on and work fine.
The other problem is when it get to temp the blower will shut off like it should then
The exhaust vent fan will run on and on. I some time come back out in the morning and it still will be running
But it won’t do it all the time.
I think it maybe the vent relay or coil and the fan control but would like to make shear before
Just buying parts? Can I check voltage?
Any help would be great
Thanks

 

[HVAC Phil]

Are you sure it has satisfied the tstat when the inducer runs continuously? If it is calling for heat and the inducer runs continuously, i would look at the pressure swith, particulary the tubing on it. Be sure the ****** passage on the inducer where the tubing hooks to hasn't got rust in it.