Diagnose
Start from what the building is doing. Land on a meter point — not a guess. Electrical first.
Pick a symptom. The board will not invent a refrigerant leak before you prove 24 V.
Start from what the building is doing. Land on a meter point — not a guess. Electrical first.
Pick a symptom. The board will not invent a refrigerant leak before you prove 24 V.