A/C Issues! We had frozen pipes and the AC wouldn't turn off.
This week I was so busy that it was only a passing a thought to realize one afternoon, I hadn't heard the central air turn 'off' lately.
I had been working, running errands, doing landscaping and lawn care, etc. that by the time I was in the house long enough (and the house, full of kids, pets and chaos) was quiet long enough for me to notice the air always seemed to be running; it had probably been running for 24 hours for all I knew.
I stopped. Listened. Walked to the thermostat.
I had it set for 76 degrees.
Running for about 24 hours for all I knew, but it was not cooling as it should and obviously not shutting off.
Had it quit working completely or gotten to 81 degrees in the house I might have noticed more quickly.
A/C won't shut off and runs continuously
The house won't cool correctly or get as cool as it should
The AC is running but the house is too warm
You find ice build up on the inside blower (your A/C and furnace unit in your house)
You find ice built up on the outside unit pipes
Things to do before calling (and paying) for a service call:
Check the temperature of your thermostat setting. Was it accidentally set to a higher temperature?
Is your thermostat set to both "AUTO" (under the word FAN) and "COOL" under the heat/cool option?
Hit the reset button on the themostat if you have one. Sometimes a reset will clear it and work.
Replace the batteries in your digital thermostat.
Check for ice build up on your outside AC unit (the big metal box outside your house)
Check for ice build up on the inside unit in your furnace room.
If there is any ice at all on the outside of the units, that means there is plenty of ice inside, where you can't see it. The outside of your unit ices last.
Go to the thermostat and turn the COOL setting to "OFF".
Under the fan setting turn it from auto to "ON".
This will cause your blower to run but your AC (cooling) is off.
Let it run continuously to blow air through the pipes and melt all the ice.
I let mine run about 6 hours.
When all signs of ice are gone, turn your blower off.
Check your air filter. A dirty air filter restricts air flower and can cause your system to ice up.
Check the vents and registers in your house to make sure they are not blocked or too many closed.
Clear the area in front of the return air vents (don't have both blocked by heavy furniture, etc.)
Check the coils outside on your AC unit. They can't be dirty or blocked!
The unit's silver coils should not be all bent, nor full of cottonwood fuzzies, dirt, grass clippings or any other matter. You can clean them various ways - but the point is to clean them. You can use soapy water and spray it down with a hose and/or you can vacuum them with a brush attachment. Be sure the air can flower through your unit as it sucks air in to cool your house.
If your unit has been blowing just air long enough to melt all the ice from the unit, you've checked the thermostat, cleaned the outside unit coils, replaced the air filter, checked the vents and made sure your drain pipes from your furnace/AC unit are clear and condensation can run out of them into a drain then it's time to turn your unit on and test it again.
Be sure you are not setting your thermostat too low or running the AC when it's the same temperature or even cooler outside the house. You shouldn't need to set it lower than about 72. I keep ours between 74-76 (when the AC is running correctly).
Thermostat should now be set to something akin to 75 degrees.
Fan set to AUTO and the second setting to COOL.
And you wait.
Check the registers to see if air is coming out nice and cool and strong from them.
Within an hour you should be able to tell if your AC is now working better after you've cleaned the coils and filters, etc.
You could have a low refrigerant level (which means a call to the service tech). Or it could be your relay switch, a bad thermostat, a leak or crimp in your duct work or a number of other issues.
At this point I suspected we had a low freon level and called my service tech. BINGO! Sure enough, my unit likes to see a high reading of about 220-225. Ours was reading 150. The lowest they ever like to see the reading? 75. Ours was reading 25.
My fix-it was the tech having to add refrigerant, and we replaced the rings and added sealant. Things I couldn't do myself. But in the past, taking the steps we do, we've managed to fix it ourselves and found the culprit to be dirty coils or blocked air filters.
Hope this helps!