This article describes how to deal with a a home A/C unit (KeepRite) that is not cooling optimally and the steps that I went thru to resolve.
Background
My A/C unit is about 15 years old and I have not replaced any parts on the unit. I did purchase a backup fan for the unit as on occasion the fan motor would make loud noises indicating potential imminent failure - but mine has not yet failed.
Issue
Recently my A/C struggled to make it to the set point temperature of 72 degrees F with the unit basically staying on all day.
Model
I have a KeepRite model N4A330AKC200
Steps Taken to Resolve
The first step was to assess the run capacitor in the unit to make sure that the Compressor was not cutting out due to a failing capacitor. I could have tested the capacitor, however since it was the original Capacitor I simply decided to replace it.
Run Capacitor Specs
The correct OEM replacement dual-run capacitor for a KeepRite model N4A330AKC200 air conditioner is 40/5 uF (MFD) at 370V/440V (historically referenced in ICP/KeepRite parts lists as part numbers 1172147 or its updated replacement 1172148).
I sourced and installed a BOJACK
Result
Replacing the capacitor did not resolve the cooling issue.
Check Charge and Clean Coil
Next step is to check the charge on the outdoor KeepRite unit. This test confirmed that the charge was very low and the unit needed to be “topped up”. However, it is also important to check and potentially clean (recommended) the A/C coil located in the Furnace prior to charging and restarting your unit.
In order to clean the A/C coil, you need to gain access to the coil in the plenum of the your furnace. If you are lucky (as in my case) there will be an access panel that you can open that exposes the coil. If not, you will need to cut a large hole to gain access so that you can spray foam the unit.
I purchased a can of A/C spray foam cleaner from Canadian Tire $12.99 Cdn, opened up my furnace and liberally foamed the unit and sealed back up the Furnace. I then called in an HVAC tech to top up my unit (charge up the unit).
With the unit charged, I started up the Furnace and the results were immediately noticeable.
Result
The result of charging and cleaning the unit was immediate. You could feel the cool air coming from the vents and within about an hour the house was cooled to the set point target temperature and the unit turned off as expected.