Discussions

We have been running our central air for the past 2 or 3 weeks. It just started to give this really bad smell and Is stinking up the house. It doesn't smell like dead animal or anything just a weird smell. Any ideas on how to maybe clean it or something?

like sewer?  
 
Since we started running our portable one with the house sealed up we get a sewer smell in the house. like when the stack is frozen over. Lately we are trying to open the windows a bit with it running and it seems to have minimized the odor.

If there is any drains in your house that you don't use on a regular basis they might be low on water in the trap. Therefore allowing sewer smell to come in the house. Any a/c unit removes humidity and moisture from your house.  
Solution is to just run water in those lines to refill the trap of water.

Not really a sewer smell but along those lines maybe kind of stale I guess I'll try running some fresh water down the floor drain.

Central air usually does not cause a problem with you sewer or sink traps because the condenser doesn't exhaust air from inside the house. I think the problem is more likely to be at the evaporator (A-Coil). I have seen them get coated with dust or cat hair to the point that they get saturated with the moisture from the evaporator. This can cause a musty stale smell.  
There should be an inspection panel on the side of the plenum. If not one can be cut out. Take it off and ck the fins on the coil. There is a spray available to dissolve the dirt etc.  
Also ck the condensate hose to make sure it isn't plugged.  

Thanks. Is that right at the ac unit out side?

There may be something dead inside the pipes / tubes connecting it. Although it may not smell like that, anything is possible.  
 
Another possibility is that you may have mold in the pipes and when it runs, it pushes the smell into the house.

The A-coil is an A shaped thing inside the furnace plenum on top of the furnace. There will be two copper lines running into it. One small one and one larger one (usually insulated ).