The filter in the house is fine.. I changed it last month and once a week it gets cleaned (we have dogs and cats.. so it can get pet hair on it pretty fast)..

I just went out and checked the unit.. I don't see any access panels on it.. so f it has an external filter I don't know where it is or how to get into it..

It is dripping out water now (condensation) which it wasn't doing this morning.. so I think it must have had some ice buildup.. not 100% sure on that though..

regardless I am going to have someone come out and service it.. like I said I have no idea when it was done last.. so I know it's due for it..

So, tonight I am either going to shut it off for the night or just let the fan run... I checked the thermostat this morning and it looked like something bumped it (I blame the cats).. so it was set lower than normal...
We have a big, tall ferret cage that was sitting near the thermostat.. so it's easy access for the cats to climb up there and act like idiots.. needless to say I have moved the ferret's cage so the cats can't play with things anymore.. yeah.. I'm mean... no more fun for the bad kittys...