Hi, Thanx in advance for any help. We have a dead thermostat. I opened it up and it had no batteries installed. I put some in and the AC still did not turn on(or the fan). After reading a few forums, i measured the voltage between R and C and it is 12V. Seems like it supposed to be 24V. In fact all the wires are reading 12V. We have a carrier AC model #:cnphp6024ataabaa and a totaline P310-1110 thermostat. I checked the breaker outside and its ok. I checked the shutoff switch near the main unit that looks like a light switch and it is on. Any ideas on what i can check next? Thanx, John

I am having trouble cooling one particular bedroom on the 2nd floor of my new home. It's a brand new A/C system, installed in a 1960's era home. It already had forced hot air heating, so A/C was added to the existing system. I did a lot of research already, and I realize the ducts were originally sized for heating only. Anyway, the main ducting is exposed in the basement. and there are 4 "feeders" that supply heat/cooling to the first and second floor. Starting from the rear (Back) of the house, and working towards the front. The first feeder supplies only the kitchen (it is clearly visible). The second feeder, supplies the two smaller bedrooms (I believe). The third feeder supplies the bathroom, and the last feeder (at the front of the house) supplies both the first floor living room, and the second floor master bedroom. The duct seems to split the air between the living room and master bedroom. I took off every register, cleaned them out the best I could with a vacuum cleaner. And discovered that inside each duct, it has a movable metal piece, so as to balance the airflow, as they say. Plus each register has a knob on the outside to adjust it also. I was able to make it cooler in the second bedroom, just by closing some of the internal louvers on the 1'st floor (the ones inside the duct, not the lever on the register itself). But I still find the middle bedroom uncomfortable and hot. The thermostat is on the first floor in between the living and dining room. There is a huge return vent in the dining room, otherwise, only a supply vent in the living room and kitchen. On the second floor there is a return duct in every room except the bathroom and hallway. Since the feeders are all located inside the walls on the first floor, I can't get access to them. I wonder if adding a duct booster to the second feeder in the basement would help? :wall: