Looking for confirmation of my diagnosis of AC not working. It’s a heat pump/AC (3.5 ton). Outdoor unit fan comes on, but compressor does not appear to be working as the total current draw is 1.5A, just enough to keep the fan buzzing around (measured with a clamp meter). Inside control board has 24VAC on Y1 (1st stage cool) and O (reversing valve, which I think changes from heat pump to AC – I’m assuming that 24VAC on O means “AC”).
I’ve got a service call in for tomorrow, just looking to see if there is anything stupid I overlooked. AC was definitely working yesterday evening, though last night I did note that at a 3 degree temp differential (81 outside, 78 inside) the unit would run for 8 minutes and off for 14 minutes, and it kept that up for over an hour. So I’m thinking it might have been broken last night and wasn’t actually cooling, but rather drawing the colder air from the basement and blowing it around the house, satisfying the thermostat. Then the hot air rose to the upstairs and the cycle started again.
MERC.
Replies
BTW, I had turned off power to the outdoor unit for a couple of hours to allow any thermal protection or short cycle protection to reset. My diagnosis was the same before and after doing that.
MERC.
On some units there's a manual reset for overpressure situations. Occasionally this will trip if you have clogged air filters or some such.