I recently bought a 2 story 3400 sqft home with a Carrier Split System Air conditoner (2 zone system).
Carrier Model# 38CKC048370 : 10 SEER, 4.0 Ton capacity ... located outside.
Tstat#1 is in downstairs dining room/hallway.
Tstat#2 is in upstairs mstr bedrrom.
Plenums are located in attic.
Tstat#1 intake (20X30) is located on second floor, middle of house in large open loft.
Tstat#2 intake (14X20) is located in large master bedroom upstairs.
It has the Smart Vent system to help maintain temperature between 1st and 2nd floor.
Prior to changeout, when tstats are on I would get strong airflow from vents with cool air.
On July 4, 2013 (hottest day this year ~105 F) the outside condenser unit started making a loud grinding sound late in the day ~4pm. The unit had been on since ~10am, statying on through the whole time since both tstats were trying to maintain setpoints (Tstat#1 = 78F, Tstat#2 = 80F). The day before I changed out both air filters with new filters.
I have a AC Home Warranty so I made appointmet for HVAC service to come check.
Upon checking they found the condensor unit was over amping (staying at 30 amps) and had leaks.
Service rep turned off breaker and suggested we do not use the system as it could cause a fire.
10 days later a new condensor was installed.
New unit = Goodman Model# GSC130481CB : 13 SEER, 4 Ton, Split System Air Conditioner
After one day with new unit
1. I found the upstairs was barely able to get down to ~82F (setpoint=79F) with outside temp ~88F. Downstairs was set at 79F and was maintaining setpoint. Service company came out next day and found that refrigerant was not properly filled. Proper fill was added but problem still exists with upstairs not able to bring temp down to setpoint (79F) with max outside temp ~90F until later in evening. Service rep said if proper fill did not work then there may be a leak in attic.
2. I also noticed the downstairs and upstairs air flow is slower than what I was used to. The higher air flow speed for each tstat kicks in at startup but goes to a slower speed shortly after.
3. With AC not able to achieve setpoints, the condensor unit is on all the time (which leads to a large electricity bill).
Is there a problem with how the new Goodman condensor unit is wired?
Is the Goodman compatible with the Carrier Smart Vent system?
With a split system does the unit require extra refrigerant?
Shouldn't the system be able to get at least a 20 degree drop indoors compared to outdoors?
The temperature and flow seemed to be fine prior to the changeout.
With new unit running continuoulsy I am hesitant to use the AC system knowing I will be generating a large electrical bill.
Advice is appreciated.