New A/C not cooling well
I just had the following Trane XV95/XR15 setup installed last week:
The handwritten quote from the installer says its a 2 ton condenser and 2.5 ton coil but I haven't found anything to back that up.
My issue is that the system isn't keeping the house cool. I set the thermostat to 78 while I'm at work and 70 at 5pm when I get home, and today the house was at 77 when I returned at 5, then went down to 76 until my wife made dinner which caused it to go back up to 77. The temp at midnight is 73 and the condenser has been running non stop. Outside temps were 96 at 5pm and 77 at midnight.
The only time the temp setpoint is reached is sometime after midnight and prior to about 7am.
I put a thermometer on top of one of the vents and it read about 12-13 degrees lower than the thermostat. I read that this is ideally 20 degrees, is that correct?
I know I could use more insulation in the attic, however my 30+ year old montgomery ward system could keep the house at a constant 68 with no issues so I'm thinking the new unit has an issue or that it may be too small.
House is a split level with 1050 sq.ft. on the main level in central Illinois.
Any advice? Would I be justified in asking the installer to come back and take a look? If so, is there anything i should mention to them?
Thanks in advance!