We get this question a LOT. Usually it’s because of dust or dirt that’s built up or animals built a nest in the AC over the winter. This cannot be understated. It is vitally important to keep the air conditioner clean! Most people will look at the fins and proclaim that there is not a spot of dust on the fins… this may be true but the dust begins to collect on the INSIDE of the fins where it can’t really be seen.
When the AC is in the defrost mode it is bringing in a little bit of air from behind the air conditioner and blowing the outside air against the inside of the fins. Any dust, dirt or pollen will collect there. Even if the back of the AC is in another room there will be dust! Does anybody walk past it with clothes on? Then there is some lint in the air.
AC manufacturers recommend sliding the mechanics out of the frame of the air conditioner once a year to clean it thoroughly. You can set the mechanical part, without the electronics on the ground and hose it down or pressure wash it to get all the dust off. The most common way to take one apart is by sliding the mechanics toward you, into the cooler. Check the owner’s manual to learn exactly how your unit works.
Be sure the drain hole is not clogged and there is no algae or dirt left on the edge of the pan after cleaning.
Regular cleaning is necessary to maintain good air flow. Every week if the back of the AC vents outside or every 2 weeks if you’re in a cleaner environment you should take a brush with 2 inch long plastic bristles, dip it in clear warm water then gently work it between the fins of the air conditioner. Thoroughly clean the fins till the water drips off clear. If the fins become clogged the air can’t pass thru and your room temperature will rise.
Stop here and clean the fins if it’s been more than a month (and especially if its been longer than 4!) that could be your only issue.
Don't overlook the obvious:
- Check the room setting on the CoolBot
- Be sure the heater wire is still snugly connected to your air conditioner's temperature sensor and pushed out of the way of the wind
- Be sure the fins sensor isn't pushed into the fins more than a half inch and that it's arranged between 2 coolant tubes
- Check the heater setting on the CoolBot. d-1 or d-0 are typical.
- Check the Fins setting on the CoolBot 1 is typical.
Also check the air conditioner settings:
- Your temperature should be set at the coldest possible setting
- The AC should be set in the "cool" mode, not energy saver
- Listen for the compressor to cycle on (you can wrap your hand around the AC temp sensor to force it on to test it)
- Be sure nothing is blocking the air circulation either in front of or behind your air conditioner.
If all of these are OK, check the calibration of the room and fins sensors on your CoolBot:
Gently slip the fins sensor out of the face of the air conditioner. If the sensor is frozen in the face of the air conditioner thaw the ice first. You can wait for it, or use a hair dryer but if you force it out it will break. Wait about 2 minutes for the fins sensor to register the air temp then using the arrow keys on the CoolBot click back and forth between the room and fins modes and compare the temperatures.
If the sensors read more than 3 degrees different then one is broken. Determine which one is bad and throw it away! One may be reading obviously wrong or you can compare the temperatures to another thermometer.
Set the CoolBot in the “workaround” mode and order a new sensor.
The room and fins sensors on the CoolBot are interchangeable. Determine which one is bad and only use the good one!
- Discard the bad sensor! If there is a secondary thermometer in the cooler check the temperatures against it. Unplug and throw away the bad one. Don’t get it mixed up and accidentally reuse it. It will always cause you problems.
- Plug the good sensor into the fins port. Gently insert the tip of the sensor tip into the fins of the AC, low and centered if it will reach but definitely not directly over a coolant tube (peek through the fins to locate the pipes)
- Leave the room port on the CoolBot empty. The display will read “ER” but the CoolBot has a really good algorithm for guessing the room temperature so it will continue to function almost normally, within just a few degrees of the set temperature, till you get a new sensor.
- Order a new sensor. If the CoolBot is less than a year old this is under warranty otherwise take an order or direct them to the web page
Always remember to handle the sensors gently. There is a little glass tube in the tip of the sensor which can become cracked rendering it useless and also a plastic coating on the tip which if ripped will allow condensation into the sensor tip. You will need to order a new sensor.