See if you can spot any ice on the lines on the inside and outside unit. Chances are the coils are frozen. You will need to let it defrost if this is the case. Could take up to 24 hours. Or less than an hour of you run the heat. Be prepared for water to leak from the inside unit as the drain may not keep up. Once fully thawed (you’ll never know when unless you can see inside an access panel, so longer is better) you can run it again. You should change the filter as low air flow can lead to frozen coils. If it happens again with a fresh filter, chances are it has low refrigerant and needs to be charged by an HVAC tech. If it’s low after one year, you probably have a leak somewhere. Hopefully it’s under warranty still.
Many good suggestions, but I didn’t see anyone bring up how well the house is holding the temperature, aka insulation or leaks. The best AC can’t keep it cool if that cool is going outside somehow. You say the vent air feels cold so it seems to be doing its best. Single pane windows, especially facing the direct afternoon sun will be hard to keep from undoing the cooling. Attic space that has little insulation will also defeat the efforts.
Yep, always my first thought. If you’re in the US you can get tax benefits by making your home more energy efficient. It’s doable yourself but hiring someone to do it will eventually pay for itself.
And for the attic don’t just pile on insulation, need a good air sealing first if that’s no good.
when this happened to me the heat exchanger inside was all iced up, turned out it was a valve in the circulation. Couldn’t fix it myself due to compressed coolant.
As others have stated, replace your air filter if you haven’t recently. Make sure it’s the appropriate size and rating. It should probably be pleated, and the MERV rating shouldn’t be too high unless you know the fan supports it.
Use a temp gun or a kitchen instant read thermometer and compare the exhaust temp vs the return temp. It should be around 15 degrees difference or more. If it’s not then an installer should adjust the pressure on the system.
If you have multiple floors you may have a vent damper for summer vs winter. In the winter the dampers may be set to help force air through the lower floor vents and prevent the hot air from rising too fast to the upper floors. If the installer or previous owner was nice the damper will be labeled for summer vs winter.
If it’s not blowing air at all, then you may have a leak or a blockage.
If theres ice on the indoor coil or on the lines outside then either the filter is clogged or your pressure is off.
If your hvac person is telling you it’s working fine and it obviously is not, call a different installer.
Has it been working alright throughout the rest of the season? I had an HVAC system that was incorrectly wired by the installers, so it actually ran the AC and heat pump at the same time, cancelling each other out. Might not be your situation but you never know!
That could be part of a problem if it isn’t circulating.
Make sure all the vents are open and not blocked by something inside. Switch filters if you haven’t recently, and make sure they are the right kind for your unit. If you can get to your duct work, see if it is leaking anywhere as that will reduce the pressure at the vents.
If you have ceiling fans, turn them on to help out. If you aren’t already, close curtains to block direct sunlight (east side in the morning, west in the evening).
I would recommend having a different company check it out since they won’t be defensive about the prior work.
You can’t “run the heat pump and a/c at the same time” because it’s a single unit. There’s a valve that slides when powered to switch the hot side with the cold side. That’s literally the only difference between a/c and a heat pump.