York Air Handler - Directional Heat Issue

York Air Handler: AHX, AHP, AVY, MX MA

Re: Directional Heat Issue

Problem Description:  Blows cold air in emergency heat and defrost

Observed Symptoms: 

• Air handler with supply going two directions (see attached drawing)
• Problem with electric heat only
• Duct to the back of the air handler gets hot air
• Duct to the front of the air handler gets cool air

Solution:  The only known solution is to change the duct or air handler configuration to a "Left-to-Right" ductwork configuration instead of "Front-to-Back".

Additional Information: 

• Test the temperature in the ductwork in Em Heat mode so only heaters are operating.
• Make sure all heaters are on by using an amp probe.
• Use a thermometer to check air temperature in the ductwork on both side (front and back) of the air handler.
• A temperature difference more than 5 deg indicates a problem.