I have a Kenmore window ac unit that is having problems.The model no. is 253/9094990 serial no.JK92908016. When I first turn it on in the morning it will run and cool good for 4-5 hours,but as the day gets hotter the compressor will shut off and only the blower motor will be running.If you turn the thermostat colder you can hear the compressor hum as if it is trying to start, but it does not start,only the blower motor will be running.The next day when I turn the unit on the compressor will come on and everything working for several hours,unit will be cooling very good.After a few hours the compressor will shut off and never come on again.I took the unit out and cleaned it real good and that helped a little,but the compressor still shuts off during the heat of the day.What do you think could be wrong?

It sounds like the compressor is shutting off by the overload from the heat. It might just need a good cleaning. I couldn't find that model number. Could you recheck it. Kenmore model numbers look like xxx.XXXXXXX . If it's a smaller window unit, take the AC out of the window and remove the cover to clean it. If it's a larger unit the condenser and evaporator will slide out as a unit. You can use a hose to wash it out, especially the condenser coils. Let it dry before you re-install it.

__________________
SERVICE TECHNICIAN: BEEHIVE APPLIANCE....... 1985-1988
SERVICE TECHNICIAN: HANSEN REFRIGERATION. 1988-1998
OWNER/SERV TECH: RICK'S APPLIANCE REPAIR...1998-2001
SERVICE MANAGER:Used Appliance store..... 2004-PRESENT
ONLINE SERV TECH: ApplianceBlog.com ApplianceJunk.com
LINCOLN TECHNICAL INSTITUTE:..................... 1977-1979
CERTIFIED TYPE 1; TYPE 2.....REFRIGERATION SERVICE E.S.

As I said in the first post I've already taken the unit out of the case,took it outside,cleaned it good with coil cleaner and water hose.But it still shuts off in the heat of the day,and the compressor will not come back on.What would cause it to do this?

Whoops, I only read the first line of your post. My apologies. A common problem is the aluminum fins on the condenser or evaporator get smashed down and block a significant amount of air flow. Does your model use a start capacitor? I can't look it up without the model number.

__________________
SERVICE TECHNICIAN: BEEHIVE APPLIANCE....... 1985-1988
SERVICE TECHNICIAN: HANSEN REFRIGERATION. 1988-1998
OWNER/SERV TECH: RICK'S APPLIANCE REPAIR...1998-2001
SERVICE MANAGER:Used Appliance store..... 2004-PRESENT
ONLINE SERV TECH: ApplianceBlog.com ApplianceJunk.com
LINCOLN TECHNICAL INSTITUTE:..................... 1977-1979
CERTIFIED TYPE 1; TYPE 2.....REFRIGERATION SERVICE E.S.

Thanks for the reply.I rechecked the model number and that is what it is.Yes the unit has a capacitor on it.By the way this is also a heat unit, if that makes any differance.The unit works well untill it gets hot and then shuts off.This unit is in an upstairs .

I'm entering 253.9094990 for the model number and nothing comes up. Maybe one of the other techs can help. If it has a double shaft motor, check that both fan blades are turning. If it has two fan motors, make sure both are working and it can move air across the compressor and condenser. Is there a good amount of air flow through the condenser coils?

__________________
SERVICE TECHNICIAN: BEEHIVE APPLIANCE....... 1985-1988
SERVICE TECHNICIAN: HANSEN REFRIGERATION. 1988-1998
OWNER/SERV TECH: RICK'S APPLIANCE REPAIR...1998-2001
SERVICE MANAGER:Used Appliance store..... 2004-PRESENT
ONLINE SERV TECH: ApplianceBlog.com ApplianceJunk.com
LINCOLN TECHNICAL INSTITUTE:..................... 1977-1979
CERTIFIED TYPE 1; TYPE 2.....REFRIGERATION SERVICE E.S.

It has a double shafted motor,and both of the blades are turning.Air flow feels strong.

OK, first thing to do is look on the model tag for the normal operating amperes. Use a clamp style amp meter and see if the operating amps is the same. Leave the amp meter on while it's running until it shuts off and stops cooling and then read the amps again. If the amps stay the same, disconnect the power and remove the two wires on the capacitor. Short the two terminals together. Use an ohm meter to check each terminal to ground or the outer case of the capacitor. If you get a reading on either terminal, the capacitor is bad. Be sure to do this after the AC has been running and then stops cooling. Then set your meter on it's highest ohm setting. Put your probes on each terminal of the capacitor then switch them around. You should get a high ohm reading that will increase and then go to open or 1. Is this a R134-A or R22 system? 120VAC or 220VAC? This is about as far as I can go without looking it up. Hopefully another tech will be able to find that model #.

__________________
SERVICE TECHNICIAN: BEEHIVE APPLIANCE....... 1985-1988
SERVICE TECHNICIAN: HANSEN REFRIGERATION. 1988-1998
OWNER/SERV TECH: RICK'S APPLIANCE REPAIR...1998-2001
SERVICE MANAGER:Used Appliance store..... 2004-PRESENT
ONLINE SERV TECH: ApplianceBlog.com ApplianceJunk.com
LINCOLN TECHNICAL INSTITUTE:..................... 1977-1979
CERTIFIED TYPE 1; TYPE 2.....REFRIGERATION SERVICE E.S.

Ok,thanks I'll do that and let you know,thanks again.

Yea, I looked that model# up as well, and I got nothing.

Yes, Rick is correct.

Its possibly a bad compressor, I remember I had one do this same thing in Texas back in 1999 or 2000. I made sure both the condenser and evaporators coils were cleaned/flushed clean with coil cleaner, and still did the same thing. It would run good in the morning hours, but in the afternoon heat of the day, it was done, compressor wouldn't come on again till the next morning.

I replaced the compressor on it and it fixed it.

From the serial# on your model, yours was made in 1999. So your compressor warranty is over, and it would cost more to replace the compressor on it, than to buy a new one.

Jake

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Appliance Repair School 1987-1988
Star Appliance Tech. 2 yrs. 1988-1990
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Sears Appliance Tech. 4 yrs. 2001-Oct. 2005
Jake's Appliance Repair Nov. 2005-present

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