Icy dehumidifier
 

I have a pretty old dehumidifier that keeps icing up now it will fun fine, i think just the fan but as soon as something kicks in the coils ice up within a minute Any ideas on the problem?

Sounds like low on freon. Those generally are not designed for service, probably cheaper to get a new one.

That's the most likly cause but a dirty filter, fan not running, dirty coils can also cause this.

kind of figures the freon was the probelem i blew ou the coils with an air compessor and used a shop vac to to suck them out. fan runs fine.

Many of them will initially ice over when first started. They ice will melt after about 10 minutes and they will operate normally. If it is too cool where they are then the ice could get a foot hold and build up. Mine will do this in the basement when the temp gets around 60. Works fine in the summer though.