C does not cool like it used to, unit runs
A/C does not cool like it used to & unit runs constantly. Most of the time it blows slightly cool to luke warm air. Last year's electric bill per month was near $800. Our house never got as cool as thermostat was set at. Freon level is full. Changed thermostat before last summer, from the original (mechanical) to a 'ritetemp' 6025 digital/programmable thermostat. I have a 5-wire configuration: Gray wire connected to 'O'
White wire connected to W2
Yellow wire connected to W
Red wire connected to RC
Green wire connected to G
Also changed out the heat pump defrost thermostat, as well as the defrost circuit board. I am almost positive that I installed these correctly since I took a before picture on my camera before doing anything. The thermostat was a little confusing, since I went from a mechanical to a digital.
Please help. Thanks in advance.
Jim
Heating & Cooling - Carrier - 38CKC042 Air Conditioner
Answers & Comments
Hi, heat-pumps are more complicated then a regular a/c to wire the thermostat. If your heat pump has a heat strip package installed, it takes more stat wires to operate it. Plus you have the reversing valve to switch over from heat to cool, so you need a wire for that. In a normal heat pump set up, 8 conductors are used to wire the stat, even though you may not use them all. The O terminal is for the reversing valve. It should be orange for this unit as cooling, the reversing valve is energized in that mode. The only unit that is made today that is backward from this is the Rheem and Ruud units as they are energized in the heat position on the B terminal. Are you sure you have put on a heat-pump thermostat? You should have terminals like this, R, O, B, W-1, W-2, G, Y, W, C. On a gas fired heat and cool unit, it will be 5 wires, RC, RH,G,Y, and W. The Red wire will be connected to either on of the R terminals as they will have a jumper to connect the 2 wires. I have never seen a gray wire in a thermostat cable? I would go to the indoor and outdoor units to see where this gray wire is connected to on the board. Y is for cooling, yellow. R to RC is right. G, green is for fan, W is for 1st stage heat, O should be to the reversing valve at the outdoor unit to change it over from heat to cool and orange in color. You may have it wired so that your heat strips are energized the same time the cooling is and they both are on! I have seen this many times and this would explain the high bills and low cooling. Check your stat Jim to make sure you have the right one. You should also have a emergency heat switch on it, and auxillary heat. The problem is in the stat. When it is on, go to the indoor unit to feel the duct to see if it is warm from the heat strips being on. If so, you can disconnect them until you get the right stat to run this unit right. Keep me posted.
Sincerely,
Shastalaker7
Sound like your system is under sized. for every 400 sq ft of living space you should have a ton of ac or 12000 btus. also check and see if your attic fan is working. any drafty windows or doors. your supply temp should be at least 20 deg colder then your return temp. also check your filter should be changed every three months this will help with air flow.