[epar12]

My central A/C unit does not have a separate air handler inside, everything is in one unit and is outside of my home. In order to get into see the coil the whole top has to be unbolted, no big deal but not a quick process either.

About two weeks ago during the day, air quit blowing from the vents but I could hear the compressor still running although the normal hum of the compressor was much louder. I shut the system off and went to the hardware store to get some coil cleaner as I figured the issue was a dirty coil and that it may be frozen up although I never checked for ice. The coil was very dirty and cleaning it seemed to solve the problem. Now, two weeks later issue is back but it is only happening at night (2-3am). Air flow quits coming from the vent so I shut off the compressor, turn the fan to on and in about five minutes everything is working fine again for the rest of t he night till about 5:30am when the temp is turned up so that the system shuts off. I checked the system for ice the other night and found none although it could be melted if it is a small amount as it takes a good five minutes to get inside the dumb thing. The system runs all day with out any problems and like I said the issue only occurs at night. I have not had a chance to check the blower fan to see if it is running but the amount of air flow from the vents does seem to be less than it use to be at times.

Lastly, I'm not sure if this makes a difference but the coil cleaner that I purchased might as well of been water as it had no effect on the dirt and grime. I used Purple power and now the coils look almost new. And yes, I rinsed the coil well after cleaning.

Thank you
Eric

[hvac1000]

It could be an intermittent blower fan relay

It could be an intermittent blower motor

It could be the blower motor capacitor BUT since the problem does not happen all the time I kind of doubt it.

Since you cleaned the coil I figured you have checked the air filter???

Does your electrical utility have an energy saver device or cut off on your unit?? Many times these are installed in different areas of the country to cut off the A/C so the power plant will not have to work past peak load. (We have them here).

The only way to find out is ice is a problem is to actually look for it while the problem is happening OR call a local HVAC company and have them check the operating pressures of your unit. It has probably been awhile since your unit was professionally looked at so now might be the time.