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Why Should I Service My HVAC System?
Great question!  I'm glad you asked.  :)  The best way to answer that is to describe what is done and what the outcome of each service may provide.
1.  Your refrigerant levels are tested and based on the type of refrigerant you have, refrigerant may be added or removed from the system to ensure it's operating at optimal efficiency.  This not only will extend the lifespan of your system but it may also significantly lower your electrical bills.  A system operating on too little refrigerant will run for much longer than it should and often times never turning off leading to motor and/or compressor failure eventually.  You might pay off the cost of servicing in just the first couple weeks of your AC usage.
2.  Your outdoor coils are cleaned and your fins are straightened within reason.  Dirty outdoor coils or fins that are severely bent can lead to poor heat dissipation and therefore an inefficient running system.  Inefficient running systems are more expensive to operate.
3.  Your plenum is reviewed for leaks (very common!).  Why are these leaks bad?  Because you're paying to cool your attic and unless there is a furry critter up there you're trying to make more comfortable that's a poor use ... more

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