I surmise that 80% of the time renters never change the air filter and we find this is the point at which they start complaining of heat and ac issues; or high energy costs.Sometimes they remove the filter because they are too lazy to buy a new one; this can cause build up on the evaporator coil and eventually cause it to fail.This is not the primary reason for my visit, just the reason we chose a 3 months as a timeframe.During this visit I assess property condition, write down all repairs and send my guy out to fix them.I DO NOT offer the tenant the option to do the repairs themselves.Instead, I bill them and any money received goes to the repairs fist, rent second.I find this is a good way to set expectations with our new tenants and make sure they know we are serious about our properties.3 months before the lease ends we walk the property again.We assess the repairs needed and either they make the repairs or we do them.We again bill them the same way.This way, when the lease comes to an end they still care about their security deposit.They have not mentally written it off and left my asset trashed.I recommend you get in there and get the repairs started today instead of waiting for her to vacate.Now is the peak rental season and finding a tenant in the middle of winter will be problematic.Also, I generally sign 2yr leases, but if the lease ends in the winter months I shorten them to end during July.Offer cash for keys if need be, or offer to assist her in the move.Whatever it takes to reclaim this property I suggest you do it now before winter hits.It will be much less of a hassle.

Not an emergency and it's probably a bad compressor that has burnt up due to dirty coils, likely clogged with dog hair. 

Love how each RE background coils together here in different scale.

Having pets long term makes your hvac stink so you have to clean the interior coil at least (might even have to change the ducts).  

Keep in mind, it is high pollen season in northern VA....but this inspector told him the ducts are dirty, pointing out wood shavings in the base of the unit...apparently from initial construction...which doesn't make sense, as I personally cleaned/vacuumed out the coils, etc.His e-mail isn't asking for payment, but it is definitely a passive way of asking.  

Is replacing the unit with a larger one the best option here since I already had this unit charged/had the coil cleaned?

@Shawn Westbrook I think I just deleted my first reply but basically I recommend an 18 gauge Brad nailer with a narrow tip that can shoot 2” nails and a grinder with a metal cut off wheel!

There is, however, evidence that dirty heating and cooling coils, motors, and air handling units can make your HVAC unit less efficient.http://www.todayshomeowner.com/hvac-duct-cleaning-...

Another good place to wipe is the back of a refrigerator, do so during your annual refrigerator maintenance when you are cleaning the coils.

Coil cleaned?