Have recently installed a new AC split type system, 4 Ton unit. Has been fine until today it seems. For some reason its not blowing cold air. Volume of air flow seems fine. Checked filter, its fine. Compressor is running but air coming from vents isnt cold. Have a tech scheduled to come out in a few days since its still underwarranty. What could be the issue? Surely it hasnt leaked coolant?

After pulling out the disconnect and shutting off the power, I hooked up my multimeter to the capacitor, I got 35ish microF on the Herm terminal and about 4ish on the Fan side, so me thinks the capacitor is fine.

  • 1
    Is the liquid line or evaporator cold at all? Compressor running outside or just fan?
    – izzy
    Jul 3, 2021 at 22:56
  • I don't think it sounds like the compressor is kicking in and neither of the copper lines are cold. Hmm, bad capacitor maybe.
    – bitshift
    Jul 3, 2021 at 23:24
  • Is the compressor contactor working?
    – JACK
    Jul 4, 2021 at 0:13
  • I have no idea if the contactor is working. I assume you mean to check voltage across its terminals? At this point im waiting for a tech to check things out
    – bitshift
    Jul 4, 2021 at 0:17

1 Answer 1


Recent installs that are not blowing cold are one of 2 things,

A system leak or a failed component like a txv (thermal expansion valve) are items I have seen since you say it’s running there are things like a failed valve in the compressor , or plugged orifice if that is the control type. The leak is much more common than most other failures. I have had a couple of coil failures where the coil had to be replaced. If it’s been +6 months it could be a bad seal on the service valves/ valve caps.

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