On this, the day temperatures reached 95, my AC stopped working. Here are the symptoms:

  1. The thermostat says "Infinity System - System Malfunction Call Technician".
  2. The condenser outside is spinning, but slowly, and only after I gave the unit a little nudge.
  3. I poked around the thermostat for some error messages and found: "VC STANDBY VOLTS", "LOW PRESS SWITCH", but I'm not sure if these are current or relevant.

Since this is a heat wave during a long holiday weekend, I'm hoping to somehow fix this myself. Any advice is greatly appreciated.

If the answer ends up being that I need to replace one of the capacitors, could you direct me to how one finds out which one of the three in the picture is broken.

enter image description here

  • You cannot diagnose and repair this yourself. Probably one or more capacitors are bad and the fan motor for condensing unit could be bad. This could be repairable by an experienced and capable DIYer, but not for the less experienced/capable. – Jim Stewart Jul 5 '18 at 10:32
  • @JimStewart I'm capable. Any hints on determining which capacitor is bad? – Wynne Jul 5 '18 at 13:04
  • I just took another look and the leftmost one has clearly mushroomed on top. So that one is definitely bad. In a situation like this, are the chances that it's the only one that's bad or others might be bad as well? – Wynne Jul 5 '18 at 13:29
  • HVAC techs use a multimeter in the capacitance setting to check capacitors. They may also go by swelling of the can. For someone without a meter pre-emptively changing the capacitors might make sense. In the last two years I have seen a capable tech replace a capacitor and the fan motor on two different condensing units, a 3.5 t and a 4 t, respectively at my house and at a relative's. The motor wasn't cheap. No doubt I could do this and save money, but I'd rather just pay for a professional job. My unit has been in service for 27 years. – Jim Stewart Jul 5 '18 at 13:48

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