Performed single system heating maintenance. I checked amps, capacitor, filter, refrigerant, electrical, heating strips, and safeties. System is performing to manufacture specifications. I spoke with the home owner about the starting amps getting close to the LRA rating. I mentioned that we may need to add a hard start kit on next visit. I offered to replace the return plenum with a combo box to allow for a 4” filter to be used. This would allow the customer a longer lifespan on her filters.