How to Check Freon in the Heat Mode

An air conditioning unit's cool mode and heat mode both require the use of freon to operate properly. When freon levels run low, mostly room temperature air begins to blow out of your home vents. This requires you to add freon into the air conditioning unit. It's suggested to fill your air conditioning unit while in cool mode as this gives better freon pressure levels. Even though heat mode creates some pressure reading problems, you can still complete this task safely.

Screwdriver
Freon canister with pressure gauge

Instructions

- 1
  Turn off the air conditioning unit and ensure all power running to the air conditioning unit has ceased flowing. This ensures your protections against electric shock while filling the unit with freon.
- 2
  Wait 30 minutes after shutting off the power to the unit. Heat mode creates an imbalance in freon pressure. This, in turn, causes fluctuating freon readings during the refilling process. You need an accurate reading to fill the unit with the proper amount of freon. Thirty minutes allows the freon pressure levels to equalize throughout the system.
- 3
  Dislodge the back cover from the unit by removing several screws with a screwdriver. Place the screws in a safe location for later use.
- 4
  Find the low gauge valve located on the refrigerant line. Insert the freon canister's applicator and pull the trigger to begin refilling the air conditioning unit. Continue filling until the pressure gauge reaches the manufacturer's freon pressure level specifications.
- 5
  Place the back cover back onto the air conditioning unit and restore power. Turn on the air conditioner and run for 10 minutes on cool mode. This forces the additional freon to flow through the unit.

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