If you are not using your Air conditioning system for heating during the coldest months, you should winterize your air conditioner following the steps below:

• Carry out a detailed inspection for any visual damage.
• Clean or replace filters. – It is always good practice to regularly check and clean your unit’s filters.
• Check the condenser.  Removing leaves and dirt from around the unit will minimize the risk of debris entering your unit during colder months.
• Covering your A/C condenser.

Your air conditioning unit is already designed to handle typical winter conditions. If you do cover your outside condenser unit, only cover the top of it – it needs to just cover down the side about 6 inches. A cover that entirely covers your system will trap moisture inside which then triggers rust and deterioration.

• Winterize your A/C unit.

The final step for end-of-the-season air conditioner maintenance:  The air conditioner should be switched off and unplugged from the power source.

If you are using Air conditioning system for heating. (reverse cycle function)

Before switching from cooling to heating:

If the AC is on, let it run until it switches itself off (make sure your thermostat is set to AUTO, not ON). When the A/C cycle is complete, turn the thermostat to OFF and wait five minutes.

Complete End of Summer Service :

• Clean or replace filters. A new filter provides clean indoor air and can increase energy efficiency.
• Examine the air conditioner for any signs of wear or damage. Check for leaks, cracks, or missing parts. 
• Contact your HVAC technician if you have any concerns about your system or it needs proper service to be done.