HVAC maintenance question

[Andreas W.]

I have a SFR with a packaged heat pump unit. The HVAC company I called for an annual maintenance visit said there is nothing to maintain. Package units are pretty much "sealed" units. So my question for HVAC experienced members is: Should packaged units be serviced regularly like split units, or is the HVAC company I called correct?

[Darwin Crawford]

No, they aren't sealed.  A typical service on AC units is cleaning the coils, throwing the High/Low gauges on it to check pressure/compressor performance, and putting a multimeter on the capacitor. 

Not rocket science, but package units are just more compact, and therefore more of a pain in the butt to service.  

To their credit, modern refrigerant systems use really high pressures, so if you do have a leak, they typically "bleed out" really fast, so some guys basically just check that it's working.  

However, in a tenant environment, with sketchy filter change intervals, cleaning the coils every year is a MUST.