This video is an amateur case study of a heat pump that failed, walking through a step by step electrical diagnostic procedure to determine the cause of failure. Few tools aside from a multimeter are needed to replicate this effort, but there are many causes for heat pump failure so the presentation is by definition incomplete. The discussion requires background knowledge and common sense both from the perspective of safety and estimation of personal competency.

The video I describe that went through the details of evaluating the capacitor and resistance of the start and run windings is listed below.

   • How to fix a heat pump that won't start  

The information provided here is offered for free and in good faith, but there are no guarantees as to accuracy or safety. Always read widely and search for at least two sources for critical information. Note that uncaptured release of refrigerant gas is illegal and unethical. No DIY seminar on Youtube can replicate the knowledge base and experience of a professional technician. DIY repair and diagnostic efforts are by definition risky and not all safety steps are shown here. If you decide to accept the risk of DIY repair, liability for any misadventure is on you.