Fridge won't stop running! (Explanation)

[ERD50]

We've been in our new-to-us home for ~ 3 1/2 years, decided I was way overdue in pulling out the fridge to clean back there and dust the coils and all. Some of that procrastination was the unknown of the water line for the ice maker and water tap. But I pulled it out slowly, enough of a loop in the copper line to get access to everything (and I had already found and marked the shutoff in the basement rafters).

Not anywhere near as dirty/dusty as I feared. Pulled off the fiber-board panel and got in there with long brush, shop vac, and finally blowing the last remaining bits out. Put the copper line through a support bracket that the installers skipped, and decided to run it through a cycle to check everything before pushing it back in place.

Well, it just kept running. I figured it would take a while since I had it unplugged to clean it all, but an hour later, it's still going! I even turned the temp settings up to their highest, and it kept running!

Now I'm worried I may have dislodged a connector or worse. But in the back of my mind, I'm wondering if this thing is a variable speed compressor that runs continuously. Find the manual, and yes, under "noises" and "troubleshooting", they say it will run 100% of the time. So that's why it never stopped!

Curious, I see the energy label says 660kWh per year, ~ 75 watts continuous 24 hrs, 365 days. So I put my kill-a-watt meter on it, seeing between ~ 40W and 140W. I'll let it run a couple days to get a longer term average. And I found the inverter on-line, it outputs a variable freq of 53 to 150 Hz, so ~ 3:1 variable in speed. Now I'm curious if the fan on the condensor coils (the hot/warm side) and the fan on the evaporator side (the cold side in the freezer section) vary in speed as well (they are marked as 12V on the wiring diagram), or they are such low wattage it doesn't matter?

edit to BOLD the 'explanation'

 

[Kings over Queens]

while you have the manual open, check for cleaning instructions. I pulled mine off the wall and went through the same process that you did until realizing I can access what needs to be cleaned from the front of the fridge by removing a small access panel on the bottom.

 

[ERD50]

BTW, this fridge is a Frigidaire DGHD2361TF1. Purchased by previous owners in 2018 or 19?

I know there are lots of complaints about the lack of reliability in new fridges, no problems for us yet (knock-on/touch wood!), but I'm disappointed in this thing. I had to do a redesign/rebuild on the vegetable drawers - the rollers are mounted in such thin plastic that they broke the plastic. I found a way that was quite involved to beef up the whole area and re-mount those rollers. So far so good.

And the stupid thing does such a poor job of keeping the temperature even. Food shoved in the back freezes, even after I've set the thermostat about as high as I feel OK with (41F, which results in warmer spots in some areas. I see the manual says to not put food near the outlet vents to avoid freezing. Well, then put a cage around those areas! Oh, but then they couldn't advertise XX.X cubic feet (arghhhh!!!!). And they also say don't put food near the temperature sensor. Well, that's where the boxed greens fit - hard no to.

I'd think that with it running 100%, the fans would keep the air moving and there would not be such a variation. And if I want my fridge at 37F, why don't they circulate a mix of air from the freezer/fridge so that air is ~ 33~34F so less likely to freeze anything? I'm going to look into some mods. Maybe my first step is get some measurements, then set the freezer to the warmest setting (6F), which might result in slightly warmer (less cold?) air circulating to the fridge section. But still be cold enough (we use a freezer in the garage at -10F for longer term storage).

 

[Golden Mean]

I've run into this recently. One thing to keep in mind is it can take the fridge hours to cool back down if it's been unplugged. I would estimate a typical fridge runs about 60% of the time even when the door has not been opened. I'd think you could reset your kill-o-watt, let it run for a 24 hours and see how many KWH it has used to see if it's running 24/7.

That said, I figured out the relay on my Jazz board was sticking, so the compressor didn't shut off when the board commanded. Really messed up the defrost cycle with the compressor running. My fridge lets you run simple tests by pushing the temp buttons (and the light toggle). I was able to figure out the compressor didn't shut off when I forced defrost mode. Once I figured that out and found the board's location, I smacked it a good one and the compressor shut off. $30 Jazz board from Amazon and a day later it's happy.

Good luck.

 

[ERD50]

while you have the manual open, check for cleaning instructions. I pulled mine off the wall and went through the same process that you did until realizing I can access what needs to be cleaned from the front of the fridge by removing a small access panel on the bottom.

Hah, I'm usually the one saying "Read the manual!", so thanks for the reminder. Man, there was nothing at all about getting the dust out of the condensor coils! Just dust the toe grill in front (which isn't gonna do much). There was a fair amount of dust bunnies clinging to the coils. How much that reduces efficiency I can't say, but this fridge is just ~ 6 YO, and our beer fridge is still going after 33 years, so if this lasts anywhere near that long, that dust problem is just going to get worse.

For all this talk about energy efficiency, you'd think (OK, "hope") that they'd provide an easy way to clean those coils from the front. But no. Get your Energy-Star rating for one new out of the box, and if the efficiency drops or the thing breaks a few years later, well, that's on you. Arggghhhh!

 

[ERD50]

I've run into this recently. One thing to keep in mind is it can take the fridge hours to cool back down if it's been unplugged. I would estimate a typical fridge runs about 60% of the time even when the door has not been opened. I'd think you could reset your kill-o-watt, let it run for a 24 hours and see how many KWH it has used to see if it's running 24/7. ...

If you read through to my explanation, you'll see it actually is designed to run continuously. It is a variable speed model, so it just slows and speeds to match demand. No cycling under normal circumstances - though I am curious to test to ensure it does shut off while in defrost mode (as the manual states it should). I can detect a slight airflow from the front, so that should stop while in defrost (but how do I know when that is?)

 

[Golden Mean]

If you read through to my explanation, you'll see it actually is designed to run continuously. It is a variable speed model, so it just slows and speeds to match demand. No cycling under normal circumstances - though I am curious to test to ensure it does shut off while in defrost mode (as the manual states it should). I can detect a slight airflow from the front, so that should stop while in defrost (but how do I know when that is?)

Ah! Sorry about that, I totally missed it.

I detected compressor on/off and when defrost was running by checking the amp pull of each mode on the kill-o-watt. Defrost (with compressor off) was like 5 A, compressor/cooling 1.6-1.8A and so on. (Figured out my fridge light bulbs pulled like 40W! Switched to led bulbs.) Might be harder on a continuously running model though.

 

[Texas Proud]

I do not know the name of it but there is a liquid you can buy that you spray on the coils and it cleans all the crap off...

I have not bought it yet but plan to soon...

 

[Koolau]

I never knew fridges were that complicated. Running continuously sounds kinda crazy, but I guess it is what it is.

We also struggle with "zones" that are too cold. The 2 year old fridge "should" be better than that IMHO. We certainly paid enough for it. I will say that it uses WAY less electricity than the one it replaced which was 12 years old (still w*rked just fine - but DW wanted a "new" one and that was her BTD choice.) We could actually see the difference in our electric bill, so there's that.

 

[ERD50]

I do not know the name of it but there is a liquid you can buy that you spray on the coils and it cleans all the crap off...

I have not bought it yet but plan to soon...

Sounds messy. I also read that some people are concerned that if you don't rinse it off completely, you've just left another layer of something to reduce thermal transfer, and/or the stuff might interfere with any anti-corrosion coating on the coils.

I think I'll stick to brush and vacuum - seemed to get the job done.

I never knew fridges were that complicated. Running continuously sounds kinda crazy, but I guess it is what it is.

We also struggle with "zones" that are too cold. The 2 year old fridge "should" be better than that IMHO. We certainly paid enough for it. I will say that it uses WAY less electricity than the one it replaced which was 12 years old (still w*rked just fine - but DW wanted a "new" one and that was her BTD choice.) We could actually see the difference in our electric bill, so there's that.

I don't know that variable speed is all that 'complicated'. I think it's common in mini-splits now. The electronics to do it as all pretty basic these days, looks like its just a variable frequency driving the motor.

Running continuously can certainly be more efficient than ON/OFF controls, but it depends. Apparently, these compressors have similar efficiency over a pretty wide range of speeds, so it works out well - just alter the speed a bit as needed. Stopping/stopping will result in some losses as things get back to operating range.

These new ones can save a few $ per month over the old (at my $0.11 kWh rates), not enough for me to want to trash a working one for new, the old ones sure seem to be reliable, I have a freezer and a beer/spare fridge that are ~ 30 and 35 YO.

 

[ERD50]

Regarding the cold/freezing spots near the air circulation vents on my fridge. This is a really stupid design. The manual says to keep things away from those spots to avoid freezing. Well, stuff gets pushed around - they should provide a cage around there at least.

What they should have done, IMO, is mix that cold air from the freezer with the fridge air on the way to the outlet vents. Some sort of venturi arrangement? That way, instead of near 0F air coming out, it could be just above 32F. I guess that would take a slightly larger fan, to mix the air?

The 6 vents are in an "air tower" at the back of the fridge - a metal shroud ~ 3/4" deep that runs from bottom (where it gets the freezer/coil air) to the top. I don't know why they didn't have these vents go out the side of the shroud, then it wouldn't hit the food directly?

I think I'm going to try some mods. I'm thinking about a bit of plexiglass to cover those vents, with a 1/2" gap to direct the cold air to the sides. I'm not to concerned about reducing the air flow - since this runs continuous, there's a very low flow, so I don't think this will really constrict it enough to make a difference. And if it did, I'm pretty sure that all that would happen is it would adjust the damper to direct more of the air to the fridge rather than the freezer compartment (that's how it balances the temperature between fridge/freezer - which have separate temperature settings).

Here's the 'air tower' - the upper left in the picture is at the base of the fridge section (bottom freezer), the slot in the middle is for the shelf brackets, and those 6 little double-slots are for the air flow. I'm not sure, but I think more air also comes out from the base, to cool the deli/crisper drawers.
FYI, my fridge is a French-door model, bottom freezer - Frigidaire DGHD2361TF1

 

[JoeWras]

What they should have done, IMO, is mix that cold air from the freezer with the fridge air on the way to the outlet vents. Some sort of venturi arrangement? That way, instead of near 0F air coming out, it could be just above 32F. I guess that would take a slightly larger fan, as they'd need to move more air total to maintain ~ 36F with 33F air.

I have a theory about this. Years ago, fridges had all kinds of fans to mix the air in the fridge and freezer. These days, they seem to have one or none. (Not including the one on the compressor, outside of the compartment.)

My thought is that the fans were energy inefficient and were jettisoned to make Energystar numbers. I also believe they were weak points in durability, requiring frequent replacement.

So the newer designs try to maximize passive cooling distribution. But this leaves more cold spots and hot spots.

 

[ERD50]

That could

I have a theory about this. Years ago, fridges had all kinds of fans to mix the air in the fridge and freezer. ...

That could be. I'm not sure if my old fridge has a separate fan just to circulate the air in the fridge compartment. I'll try to check that out.

I actually am thinking about adding a tiny 12V computer-style fan, I might be able to tap it into one of the LEDs and hot wire that to constant ON. But I'm afraid if I try to get it into the air stream of the cold air from the freezer coils, I might end up pushing air back or otherwise mucking things up.

I'll try simple first.

 

[Koolau]

I have a theory about this. Years ago, fridges had all kinds of fans to mix the air in the fridge and freezer. These days, they seem to have one or none. (Not including the one on the compressor, outside of the compartment.)

My thought is that the fans were energy inefficient and were jettisoned to make Energystar numbers. I also believe they were weak points in durability, requiring frequent replacement.

So the newer designs try to maximize passive cooling distribution. But this leaves more cold spots and hot spots.

Meeting gummint regs (or let's call them "expectations") sometimes becomes more important than meeting customer expectations. I recall the early "pollution control" solutions for cars. They w*rked but made cars less drivable, less efficient and more expensive. I think they finally got it more or less right, but it took a while.

With a little luck, I'll live long enough to get the "perfect" fridge - next time.

 

[ERD50]

UPDATE: I wanted to get some data before making any mods. I taped one small thermometer probe so it hung right in front of one little vent, the other hanging in air, and ran the wires out the door so I could monitor those temps. These don't log or show min/max, so I just had to try to sample. The probe is small and responds pretty quickly. I also had a thermometer that logs and connects to my tablet over Bluetooth and shows a graph - that one responds slower and does not have a probe, but I stuck it in front of one of the vents to get an idea of what's happening there.

The Bluetooth one did show a surprising pattern. Since I knew the compressor was running continuously at variable speeds, I expected a fairly constant air temp at the vent - varying just enough to respond to the door opening, etc. But I saw a clear pattern of about 30 minute rise and 30 minute fall. Hmmm.

So I would check the vent probe at the near top/bottom of the cycle, and saw a tremendous change about in sync with the slower readings. The vent probe cycled between about 5F and 34F. No wonder food that gets pushed near the vent freezes!

But why does it cycle, if the compressor runs continuously? My guess is that this is how it controls the relative temperature of the freezer and fridge compartments. The wiring diagram references a 'damper motor', but I have not found it on any parts list. In old fridges, this was a manual control that adjust the air flow between the two. So the thermostat controlled the fridge, and if the damper was more closed, the compressor ran longer to get the fridge cold, so the freezer would be colder. If the damper was more open, the fridge cooled faster, the compressor ran a shorter time, so the freezer was less cold. There was no real feedback for the freezer temperature, it was just a side effect of that damper setting.

So it appears that the damper is more of a traditional ON/OFF control for the fridge, while the FREEZER temp setting adjusts the compressor to keep the freezer in range - the opposite of the older style. I was thinking that damper was variable, and would adjust itself to a small range to maintain a set temp until a door was opened or hot food was added. But maybe having TWO things varying to control temp would result in some 'tricky' control logic? So this keeps it simple?

I wish it was easier to get to the control board, but I think I have to pull the fridge out to get to it. I'd like to tap into that damper control wire, to see what's going on. But it is what it is, I'll look into adding some deflectors and see what I can accomplish.

 

[Koolau]

UPDATE: I wanted to get some data before making any mods. I taped one small thermometer probe so it hung right in front of one little vent, the other hanging in air, and ran the wires out the door so I could monitor those temps. These don't log or show min/max, so I just had to try to sample. The probe is small and responds pretty quickly. I also had a thermometer that logs and connects to my tablet over Bluetooth and shows a graph - that one responds slower and does not have a probe, but I stuck it in front of one of the vents to get an idea of what's happening there.

The Bluetooth one did show a surprising pattern. Since I knew the compressor was running continuously at variable speeds, I expected a fairly constant air temp at the vent - varying just enough to respond to the door opening, etc. But I saw a clear pattern of about 30 minute rise and 30 minute fall. Hmmm.

So I would check the vent probe at the near top/bottom of the cycle, and saw a tremendous change about in sync with the slower readings. The vent probe cycled between about 5F and 34F. No wonder food that gets pushed near the vent freezes!

But why does it cycle, if the compressor runs continuously? My guess is that this is how it controls the relative temperature of the freezer and fridge compartments. The wiring diagram references a 'damper motor', but I have not found it on any parts list. In old fridges, this was a manual control that adjust the air flow between the two. So the thermostat controlled the fridge, and if the damper was more closed, the compressor ran longer to get the fridge cold, so the freezer would be colder. If the damper was more open, the fridge cooled faster, the compressor ran a shorter time, so the freezer was less cold. There was no real feedback for the freezer temperature, it was just a side effect of that damper setting.

So it appears that the damper is more of a traditional ON/OFF control for the fridge, while the FREEZER temp setting adjusts the compressor to keep the freezer in range - the opposite of the older style. I was thinking that damper was variable, and would adjust itself to a small range to maintain a set temp until a door was opened or hot food was added. But maybe having TWO things varying to control temp would result in some 'tricky' control logic? So this keeps it simple?

I wish it was easier to get to the control board, but I think I have to pull the fridge out to get to it. I'd like to tap into that damper control wire, to see what's going on. But it is what it is, I'll look into adding some deflectors and see what I can accomplish.

Would it be worth a call to their technical service folks? If you reached the right person, they just might tell you the truth (whole truth) of how it all w*rks.

If you start with the "issue" of freezing in places and too warm in others, you just might get a human to explain what they actually do to keep the fridge w*rking.

 

[ERD50]

Well, the manual just says don't put things by the vent. I doubt anyone I can get hold of would say anything different.

Food in Fresh Food Compartment

Food is freezing:
•Temperature setting is too low.
>>>> •Move the setting to a higher degree.

•Temperature sensor is covered by food (right side of fresh food area).
>>>> •Allow space for air flow to the sensor.

•Food is covering the air ports.
>>>> •Allow space between the air ports and the food.