On the covered Kenmore window air conditioner, with or without heater, CS means a failed condenser temperature sensor, the sensor on the outdoor coil. First, unplug the air conditioner before opening anything. Then: look at the harness connections on the control board and the board for damage, and check the condenser sensor's wires for a pinch or a break. A defective sensor is replaced.
Differential
Likely causes of “Kenmore window air conditioner, with or without heater code CS”, and how to tell them apart
- 1
The sensor on the outdoor-facing coil has failed (CS)
What separates it The unit stops after running for a while and CS appears
How to confirm Unplug the unit and look at the sensor clipped to the back coil
- 2
A coil clogged with dirt, leaves or cottonwood
What separates it The back of the unit is furry and airflow is weak
How to confirm Vacuum the coil and straighten the fins
- 3
A curtain, a shrub or a wall hemming in the rear
What separates it The unit is installed too close to something
How to confirm Give the back at least a hand's width of space
- 4
A sensor wire damaged where it passes the coil
What separates it The wire is melted or nibbled
How to confirm Replace the wire or the sensor
- 5
A control board that misreads a good sensor
What separates it The sensor tests well
How to confirm Replace the board last
Before you touch a setting
Record this first — changing settings destroys the evidence
- That CS appears after the compressor has been running for a while and not at start-up
- Whether the back of the unit is clean and has room to breathe
- Whether the unit has a heater and which mode it was in
- The model number and date of manufacture from the label
Try in this order
0 of 8 completedWhat to do first
ReversibleUnplug the air conditioner before opening anything.
Correct only the documented fault domain
ReversibleLook at the harness connections on the control board and the board for damage, and check the condenser sensor's wires for a pinch or a break. A defective sensor is replaced.
Unplug the unit and look at the back
ReversibleSlide the unit out of the window frame if you can do so safely, or reach the back from outside, and look at the coil for dust, leaves and fluff.
Vacuum and comb the coil
ReversibleUse a brush attachment on the fins and a fin comb on any that are bent. A clean, straight coil sheds heat much better.
Check the space behind
ReversibleMake sure that the unit has room to breathe, with no curtain, shrub or wall pressing on the back.
Find the condenser sensor
ReversibleIt is a small bulb or probe clipped to a pipe on the coil, with a thin wire running to the control board.
Check the wire and the clip
ReversibleA wire that is nibbled, melted or pinched, or a clip that has come loose, will give a false reading.
Replace the sensor if it fails
ReversibleIf the coil is clean and the wire is sound, a new sensor with its clip is the repair.
Model-specific
What is true of this model and not of its siblings
- The code on this page
- CS, a failed condenser temperature sensor, the sensor on the outdoor coil.
- Parts involved
- The condenser sensor, its wires and the control board.
- Source
- Sears PartsDirect's table for Kenmore window air conditioners.
- What the condenser sensor does
- The condenser coil is the outdoor-facing coil that releases heat. Its sensor tells the control how hot that coil is, so that the control can protect the compressor if airflow is poor. When the sensor fails, the control cannot judge the coil and stops the unit.
- Clues from the outdoor side
- A condenser sensor code is more likely if the back of the unit is blocked by a curtain, a plant or dirt on the coil. Vacuum the rear coil and clear the space behind the unit before you replace any part, because a dirty coil can also set off the code.
- Condenser airflow and CS
- The condenser coil faces the outdoors and sheds the heat that the unit removes from the room. If a curtain, a shrub or a coating of dirt blocks the air at the back, the coil runs hot, and the control reports CS even though the sensor is healthy. Cleaning the coil and clearing the airflow is the free first check.
- Heating and cooling modes
- A Kenmore unit with a heater uses the condenser sensor in both modes. Tell the technician which mode was running when CS appeared, since a code in heating mode points at a different part of the cycle than one in cooling.
- Ordering the sensor
- Ask the parts counter for the condenser sensor by model number, because the sensors differ in wire length and clip between models. A sensor that does not clip securely to the coil reads too cool and causes new faults.
Stop boundary
When this stops being a self-service repair
- !Clean the back coil before ordering anything, since a hot coil sets CS on a healthy sensor
- !If the sensor wire is melted, replace it and the clip together
- !Do not run the unit with its back against a wall or a curtain
Evidence ledger
Sources behind this answer
Exact questions
Common questions
What does CS mean on a Kenmore window air conditioner, with or without heater?+
a failed condenser temperature sensor, the sensor on the outdoor coil.
Why did it appear after a hot week?+
A coil that is dirty runs hotter in hot weather, and the control sees the high reading.
Can I clean the coil myself?+
Yes, with the unit unplugged, a vacuum and a soft brush.
Is it the same as ES?+
No, ES is the indoor coil sensor, and CS is the outdoor one.
Is the sensor expensive?+
It is an inexpensive part.