Help with unfulfilled HVAC repair!

[Nick Brubaker]

Hello all,

About 4 weeks ago now the tenant at my rental property contacted me to tell me the AC wasn't working. I reached out to the guy I usually call on for both HVAC and roofing matters.  He is a licensed HVAC servicer, but not part of a bigger company - he was recommended to me by another local investor and was also the one who installed the unit in the summer of 2016.  At that time he signed off on a hand-written warranty for parts and labor for 10 years.  He told me that lightning was the reason for the failure in this case and as a result it would cost $500 for both the labor and new compressor (under warranty with the unit).   He came out later and "repaired" it and I paid the $500, but just a couple days later the tenant was complaining that it was either very weak or not working at all.  The guy came back out and spent a good amount of time working on the unit trying to find the issue (I believe it was tough and frustrating work).  The next day he said the he had decided that he would install a new unit rather than try to fix the other, but that he would not handle any servicing of it.  This sounded a little sketch to me, but this is lease renewal month and it had already been 2.5 weeks so without agreeing explicitly (maybe implicitly) to his contrived terms I allowed him to go ahead and install the new unit.  Again though, I was very suspicious about the idea of installing a unit without being accountable as the servicer.  It checked out though that the unit was new and I was able to register it with Goodman.  No additional cost.  Anyway, low and behold 6 days later the tenant messages me to tell me the unit is power surging or something because the lights in the house were flickering and it was making a loud noise outside.  I have contacted the contractor twice today - I have heard nothing back and am expecting I won't.  So where does this leave me?  What suggestions do you all have?  

A few other questions:

Those with more experience: Is this power surging common?  Does it suggest a major issue or minor?

Should I try to enforce the original warranty agreement?  Should I attempt to get my $500 back and if so what would be the suggested way of going about it or just let it go and lick my wounds?

If I have a different HVAC contractor come out, will that void the warranty?  Are warranties transferable in cases like this where the installing contractor disappears?

Any of you living around Atlanta:  Can you recommend a good HVAC contractor or company, particularly for rental-tier properties?

Thank you!!

Nick