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...

York Air Handler: MP, MX, MV, AHP, AHX, AVY Re: Disable Code 3 The control board in the air handler monitors the limit switch in the aux heaters. If the limit trips 3 times during a single heating cycle the board will go into a lockout and flash a code 3. This causes the fan to run...

York Air Handler: MP, MX, MV, AHP, AHX, AVY Re: Some Auxiliary Heaters Not Working The 4HK heater kits for these air handlers consist of In-line beakers, a control board, snap-disc limits, and DC voltage relays. The control board has two heat stage inputs, "W1" and "W2". In most instances,...