Sears refrigerator makes ticking noise, runs long time

[Cletus]

Sears Coldspot model 106.6684240
Freezer on top, No icemaker, self-defrosting
Unit is cooling

I have cleaned all built-up dust off precooler, behind kickplate, against wall, and used nylon brush to clean condenser coils.

A couple of days ago, I noticed an unusual ticking I hadn't heard before. It sounded like metallic dripping. It made a series of ticks and then a pause (the normal hum was uninterrupted). I put my ear up to various places and it sounds loudest either inside the refrigerator part or against the side that has the thermostat/cold control.

I started timing how long it runs, something I've never done before.
(1) Please tell me how long should a refrigerator 3/4 full at room temperature 70F with no direct sunlight or oven on in the kitchen normally cool before cutting off?

I found it running 45 minutes, off 15 minutes, then back on for 60 minutes. This seems too long to me, I'm used to air conditioners running less than half that time before cycling off.

I did some extra cleaning with the nylon brush and listened after plugging it back in. Immediately it came on and I heard the gurgling of the refrigerant, normal hum, it cools... 1 hour and 45 minutes later after several series of ticking noises it cuts off. I'm wondering if the water has frozen in the coils but I don't see any frost or ice on the condenser coils.

However, the next time it runs for 2 hours and I open the refrigerator and turn the cold control just a little and it cuts off and I immediately recognize the tick sound. My guess is the thermostat is going bad since it's cooling fine. I'm worried about the condenser overheating with these long run times.

I put a temperature gauge in and find it's trying to cool the refrigerator down to 33 F. The cold control hasn't been adjusted for a decade or more.
(2) Can the thermostat gradually adjust itself out-of-sync with the knob itself? Vibration? Power Surge?

Now I find adjusting the cold control from the "2.5" it was on to "2" that the temperature is now 42 F. It's running about 35 minutes and turning off for 15-20 minutes.
(3) Is it now back to normal? It's still ticking after it runs for 15 minutes or so.
(4) Should I replace cold control? Is this a part I can replace?

Thank you for taking the time to read and answers to any of the above four questions would be greatly appreciated.

[Dan O.]

It sounded like metallic dripping. It made a series of ticks and then a pause (the normal hum was uninterrupted). That might be defrost water dripping, expansion or contraction of metal during or after a defrost, the compressor cutting out on its overload protector, the thermostat or defrost timer contacts opening or closing during operation (see the following link).

LINK > My refrigerator is making strange sounds. What is wrong with it? (http://www.appliance411.com/links/jump.cgi?ID=768)

Please tell me how long should a refrigerator 3/4 full at room temperature 70F with no direct sunlight or oven on in the kitchen normally cool before cutting off? There is no set amount time. A modern refrigerator could run 70-80% of the time.

I found it running 45 minutes, off 15 minutes That would be 75% of the time. It could very well be normal although I would think the length of times for each might be less but there are so many variables it is impossible to say.

I'm wondering if the water has frozen in the coils but I don't see any frost or ice on the condenser coils. That's good because the condenser is the HOT part of a refrigeration system. The evaporator is the cold part.

Did you actually remove the panel(s) in front of the evaporator coil and inspect it directly?

Can the thermostat gradually adjust itself out-of-sync with the knob itself? Yes a thermostat can loose its calibration with age and use.

Now it's running about 35 minutes and turning off for 15-20 minutes. That sounds a bit better but as I said there is no set on and off run times. It will run until the control senses the temperature it is set to, however long that takes. It will be off for however long it takes the temperature to rise again.

Should I replace cold control? If it's keeping the temperature you want, it likely doesn't need replacement at the moment.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site (http://www.appliance411.com/parts/?ref411=Kenmore+Fridge)
=D~~~~~~

[Cletus]

Now it runs 45 min. or longer, reaches proper temperature inside, shuts off, then turns right back on as the ticking noises try to re-engage the compressor. It sounds to me like the thermostat keeps wavering and not making contact long enough to send the current needed to restart the compressor, resulting in clicks (when it shouldn't be re-engaging it at all).

(Note: "ticks" eminate loudest with refrigerator door open. "Clicks" eminate loudest from bottom back of refrigerator and only when unit is trying to come on--and only after it's just shut off. For instance, if it does rest 15 min. and comes back on, it's one click and comes on clean with normal hum.)

If I move the cold control knob from 2 up to 3 and back down to 2, it usually cuts off. That makes me suspect thermostat as the root of the problem. The ticking only occurs when the unit is running and usually only if it's been running more than 20-25 min. (like it's trying to cut off but can't make the circuit long enough to send current to turn off compressor) or if it comes right back on after cooling 45 min. when the temperature in the refrigerator is 34 F and it shouldn't be coming back on.

I haven't removed panel in freezer to look at evaporator coil because it's full of frozen garden vegetables and would be very difficult to reach. But nothing in the freezer seems unusually warm or soft--or has any freezer burn.

Unless you think there's any way to clean metal contacts on the thermostat, I feel I need a new one to avoid my compressor burning up. (45 min. on, 1 min. off then 60 min. on again doesn't seem safe for the compressor to me) While the replacement part at Sears is supposed to fit this model it is a substitution and might need modifying. Is a thermostat something I can replace myself? (I have replaced contactors on outside air conditioners before so I have some electrical experience.)

Thank you for the response, Dan. Let me know if you think I'm on the right track and could replace it myself?

[RegUS_PatOff]

Is it "ticking" or "clicking" ?

How often does it click ?

Is it one click, then a pause for a few minutes, then another click ?

Is the Compressor hot ? (can't hold your hand on it)

[Cletus]

RegUS PatOFF: It goes tick, tick, tick-tick, TICK, TICK, tick... then continues running, then goes through series of ticks again, sound is loudest at cold control inside unit. Never ticks when off.

It goes click-click-click-click and starts if thermostat makes contact and sends enough current. If not it's quiet and then tries again with a series of clicks. But this is only if it has run a long time, 60 minutes, cuts off, and then tries to cut right back on. Like I said above, if it rests 10-15 minutes, there's one click and then a gentle hum as it runs normally. This makes me suspect thermostat and not start relay.

I can actually get it to start ticking if I mess with cold control knob--or I can get it to turn off by messing with cold control knob. It's not reliable which it will do. But understand, until I began hearing these ticks and noticing it was running a lot sometimes with only 30-60 seconds of rest (but still cooling properly) a couple of days ago, I hadn't touched the cold control in so many years I had forgotten which way to even turn it. So it's not from over-using the knob. However, calibration being off like Dan suggested sounds reasonable. I have heat thermostats in the house that are old and their calibration is off so that if it says 65 it's really keeping the room 70 (but that's a digression).

I know it's getting long, but anyone with ideas, there are a lot of facts throughout these postings to give clues.

[DIY Guy]

Cletus, let me suggest that if the refrigerator is cooling well, and aside from the clicking, there are no other problems, there is little harm in just waiting for a part to fail.

If you figure out the problem, if one exists, and replace the part before it fails, you do save yourself some down time on the fridge. Beyond that the cost and effort will be the same whether you wait for a part to fail or you replace it before failure.

The largest concern I believe you have is that the compressor might be working too hard and may burn out. However, it does have an overload protector which should protect it from doing so.

You first descibed the sound as a "metallic dripping". This makes me suspect you are hearing the water in the defrost drain tube dripping into the pan.

[Dan O.]

Now it runs, reaches proper temperature inside, shuts off, then turns right back on as the ticking noises try to re-engage the compressor. It shouldn't try to start right back up again.

"Clicks" eminate loudest from bottom back of refrigerator and only when unit is trying to come on--and only after it's just shut off. That will be the overload protector cutting out. A compressor needs to sit 5-10 minutes after shutting off to allow the refrigerant pressures to equalize before starting again.

If I move the cold control knob from 2 up to 3 and back down to 2, it usually cuts off. That makes me suspect thermostat as the root of the problem. You mean if you turn it WARMER then COLDER again, that's when it shuts off??

The ticking only occurs when the unit is running and usually only if it's been running more than 20-25 min. (like it's trying to cut off but can't [break] the circuit long enough to [stop] current to turn off compressor) I've never heard of a thermostat acting in such a manor but it might be possible?

I haven't removed panel in freezer to look at evaporator coil because it's full of frozen garden vegetables and would be very difficult to reach. But nothing in the freezer seems unusually warm or soft--or has any freezer burn. If the refrigerator was running excessively it should be excessively cold, often freezing food in the fridge compartment. If it is running too much but NOT too cold it is not cooling properly. Inspection of the evaporator coil would be one of the first things that needed to be done in such a case.

Unless you think there's any way to clean metal contacts on the thermostat, There isn't.

I feel I need a new one You can see the thermostat for your model at the following link. It shouldn't need any modifying.

LINK > Coldspot 106.6684240 Thermostat (http://www.appliance411.com/data.php?ap=8201506)

Is a thermostat something I can replace myself? I have no idea of your abilities but replacing a thermostat is usually one of the least difficult repair jobs to perform on a refrigerator.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site (http://www.appliance411.com/parts/?ref411=Kenmore+Fridge)
=D~~~~~~

[Cletus]

Someone outside the forum suggested that the thermostat would not make clicks even though source of noise is loudest near it. I checked defrost timer to see if the ticks eminated from there and the noise was faintest at that location.

New: Refrigerator now runs all the time. It does not cut off. No more ticking. I have to unplug it every three hours to let compressor rest. I felt condenser coils after three hours. Yes, there's warm air which is normal but it is not excessively hot. Temperature inside refrigerator is 38 F. I have ordered a thermostat but now wonder if there's any chance I've misdiagnosed and it could be the defrost timer. Moving cold control from colder (2.5) to warm (1) does not make the unit turn off anymore.

Thank you for responses. Any more ideas?

[Cletus]

The unit finally stopped cooling and the freezer temperature reached 32 F so I had to transfer everything to coolers and call an emergency repair service.

The defrost timer motor had stopped working.
Evaporator coils were a solid block of ice.
The repairman said everything else seemed to be working.
Installing the new defrost timer, he advanced it to see if heater was working and it sizzled. Compressor was hot before he started, so it had been running.
After two hours, the freezer was already back down to 0 degrees, faster than I expected. Although, it hasn't been through an entire 24 hour cycle yet.

Thanks to all who read and especially those who answered.

One more question--perhaps Dan will know--
When the freezer goes into defrost and the heater comes on, what temperature will the freezer go up to until it switches back into cooling mode? 25 F? 32 F? What temperature melts the frost?

[Dan O.]

When the freezer goes into defrost and the heater comes on, what temperature will the freezer go up to until it switches back into cooling mode? On mechanical timer models switching out of defrost mode has nothing to do with temperature. It is strictly time controlled (see the link below).

LINK > How does a frost free refrigerator's defrost system work? (http://www.appliance411.com/links/jump.cgi?ID=658)

What temperature melts the frost? Usually 33°F+. :rolleyes: Although the defrost heater emits radiant heat to defrost not conductive heat which would require the whole area around the evaporator to drastically rise in temperature before any thorough melting could occur.

I do not know what temperature the area nearest the heater or the freezer compartment itself would get to during a defrost but since the fan is not running, that warmth does permeate the appliance to any degree. Frozen food also takes quite a while to thaw and is not usually affected by slight or short duration temperature increases.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site (http://www.appliance411.com/parts/?ref411=Kenmore+Fridge)
=D~~~~~~