Large top/bottom temperature differential in Jennair JBBFX24NHX

You're right. The freezer is cooling fine. It's just the fridge that's been having issues.

I checked the leveling with a spirit level and everything's good there. This is a panel-ready fridge so it's difficult to do the standard seal tests because the panel gets in the way. That said, your suggestions caused me to go back and re-read through the installation guide.

One key callout is that there needs to be at least 1mm between the back of the door panel and the front of the frame. I checked the fridge in a friend's unit and it didn't have any sound of wood on wood. It resisted opening as though sealed. His temps were fine.

I unscrewed the unit and pulled it forward about half an inch. The door now closes silently without any wood-on-wood sound and gives the classic fridge opening resistance. I measured the temps and, while not perfect, they're food safe now. Now, the bottom shelf reads ~38F while the top shelf consistently reads 39-40. I also saw that that condensation is no longer frozen.

Thank you!

@bjornsen

Glad you got it sorted.

There's always a slight temperature gradient between the top and bottom shelves, so they'll never be the same.

This is because cold air is denser and sinks as opposed to warmer air which rises. Due to normal usage i.e. doors opening (letting warmer air in), new items being stored etc it is rare for the entire compartment to be at the same temperature all the time. Maybe check first thing in the a.m. as this is the most likely time that it will be the same all over due to little or no activity occurring overnight with the fridge door and any new items should have reached the fridge's "ambient" temp by then and would've stopped giving off heat (as compared to the colder temp in the compartment)

As long as it's within the range of 37°F - 40°F it should be OK

Cheers

Good advice! To avoid too much variability, I have glasses of water sitting on the top and bottom shelf and am temping them with an instant read thermometer in the morning when I get up. Before the fix, there was a greater than 5 degree difference between the top and bottom. Now, there's usually around 1-2 degrees.

@bjornsen

That seems about right.

The only time when both the bottom and top shelf temperatures may be higher than expected is if they're measured at or near the end of a defrost cycle. This is due to the compressor not being operated to drive the temps back down again if they happen to rise above the preset upper temp limits. Usually it is only a few degrees and it is more noticeable in the freezer compartment e.g. ice cream may be slightly softer than usual, but it is never high enough to even being to start defrosting frozen foods in the freezer but the temp in the refrigerator may be a bit higher than the normal range you're seeing now

During the defrost cycle the compressor and evaporator fans are both turned off and the defrost heater under the evaporator unit is turned on to melt any accumulated ice from the evap unit which then drains away to the evap pan under the compartments where it evaporates naturally.

Depending on what method is used to initiate the defrost cycle will depend on how often it is run.

For example if the compressor elapsed run time method is used then the cycle usually happens every 8-10 hours (depends on manufacturer) and it lasts for about 20-25 minutes.

If the compressor accumulated run time method is used the time between cycles can vary due to how long it takes for the compressor to have been running for the required amount of time i.e. the compressor doesn't run all the time, it only runs long enough for the set operating temps to be reached in both compartments and then stops. It only starts again when the temp(s) rise above the preset upper limit to drive them back down again. How long it takes and how often it runs to do this depends on things like how often the doors are opened and what the ambient room temps are where the refrigerator is located etc so it could take anywhere from 8 hours to 24 hours before a defrost cycle occurs. The length of the cycle is about the same 20-25 minutes.

Sorry to prattle on but I find that if you know how things are supposed to work it makes it easier to find out what's wrong when it doesn't.

Cheers

I appreciate the prattling. The extra knowledge helped quite a bit. I was alarmed when after a few days of stable temperatures, I woke up to 44 degrees in the upper fridge shelf. Having read this, it was likely just a defrost cycle. The next morning I was back under 40 again. The more you know!