Hi,

I have a traditional top-freezer fridge/freezer unit in our kitchen. For the past two weeks or so there has been a significant amount of condensation on the frame of the appliance below the bottom of the freezer door seal and above the top of the fridge door seal (about a 3/4" gap between the doors). This is on the exterior side of the appliance. I took a closer look last night, and I notice there is also moisture on the interior side of the bottom of the freezer door seal, where it contacts the frame to make the seal. There is similar moisture on the interior side of the top of the fridge seal.

The air conditioning has been on for most of the summer and I don't suspect there has been a significant humidity change in our kitchen. So I assume that a seal is leaking, but there are no obvious gaps and I don't know how to tell if the freezer or fridge seal is the problem. The moisture is also full-width across the entire appliance.

Thoughts?

This is only an observation from someone who's had the same problem, for years. When the a/c was working, there was condensate at the base of the freezer door (top freezer, bottom frig), and other areas as you described.

The a/c hasn't worked now for more than a few years, there's still condensate, but no more than there was with the a/c running.

I suspect the cold air that escapes whenever the freezer door is opened condenses and causes the moisture, but this is only my uneducated opinion.

As to little change in humidity level in the kitchen despite this being a record hot summer, I think the issue would be more how much cooking is done in the kitchen. I put a hygrometer in my kitchen to check temp and humidity before and after cooking, not with the oven but just on the stovetop, for maybe an hour or so. I also did dishes, which releases a significant amount of moisture into the air.

The temp rose from low 80s to around 90; the humidity rose about from about 35% to 45% - 50%. Together the rises were enough to make the kitchen miserably uncomfortable.

When just baking in the oven, the temp rises but the humidity does not.

There may be something going on with your freezer/frig as well, but I thought I'd just share my experience with you. Stovetop cooking, especially with boiling water, releases a lot of humidity into the air. I know nothing about the migration patterns in a particular kitchen configuration, but suspect that the humidity moves within the kitchen and ends up on a lot of different surfaces. But the only place it shows up is on the frig/freezer area.

I'd be interested in hearing the pros' observations on this problem.

Use a bill, a $1.00 will work to check the seal. You should not be able to simple slip it out without tuging on it hard.
A nonworking fan in the fridge, or a defective defrost valve are two other things that can cause this.

JKeefe:

Look on your refrigerator for something called an "Energy Saver" switch. The energy saver switch turns power on and off to a long narrow electric heater (called a "mullion heater" ) that heats the mullion between the fridge and freezer precisely to prevent that condensation you're seeing.

Newer high efficiency appliances do away with that energy saver switch and run the warm condenser coil tubing from the large coil on the back of the fridge, around the side of the fridge and across the front mullion between fridge and freezer. Using waste heat from the condenser coil to heat the mullion ensures the mullion is ALWAYS warm, and so condensation never forms in that spot. That loop in the condenser coil is called a "Yoder loop", "condenser loop" or "mullion loop". With each major appliance manufacturer calling it something different, the terminology is still tentative.

A leaking seal at the TOP of your fridge door would not be an issue. The air in your fridge is colder than ambient, and so it would leak through any break in the seal at the bottom of the door. I've had fridges that I could tell if the interior light was on through the gap at the top of the fridge door, and they worked fine for years.

The way to check your freezer door bottom seal is with a piece of paper or dollar bill as Joe said. Close the door on the paper and then try to pull it out. It should put up a pretty good fight to stay in because of the magnets inside the door seal.

Note: fridge and freezer door seals will only have magnets in three of their sides. The hinge side will never have magnets in it.

Either someone's pushed your Energy Saver switch, or the mullion heater itself is burned out. My guess would be that the mullion heater itself is kaput.

If it's not a problem, I'd consider just leaving it the way it is. Clean any mildew off the mullion and door seals with bleach periodically, and that fridge will still last a long long time.

All of my fridges have Yoder loops, so I've never replaced a mullion heater. If you want to save money by doing the work yourself, your best bet is to find out who the manufacturer of your fridge is, phone their 1-800 customer service phone number from their web site and find out who the factory authorized service depot in your area is.

Talk to the nice man at the Factory Authorized Service Depot, explain the condensation problem and see if he agrees it's the mullion heater. If so, buy or order a new mullion heater at the Factory Authorized Service Depot, where you'll pay about twice as much for the part than at any appliance parts store.

The reason you want to pay more and buy it from the Factory Authorized Service Depot is that they'll give you all the tech support you need tossed in free of charge. So, if you're having problems and running into trouble replacing the mullion heater, you can phone them and they'll give you free advice on how to overcome your difficulty. So, you pay more, but you get more in the way of tech support, and you still save money over having someone do it for you.

This message has been edited. Last edited by: Nestor,

Heater switch was off. Chalk this one up to lack of observance; I didn't even know a switch existed. Thanks for pointing it out.

I turned the switch on yesterday morning and things have been dry since.

No, usually what happens is that when people see a switch labeled "Energy Saver Switch" they turn it to the "On" position cuz they don't know what the switch does, but they figure the fridge will work equally well, but just use less electricity. And, in fact, that's correct.

But, turning the Energy Saver switch to the "On" position means that you're saving energy by stopping power flow to the mullion heater. And, that results in a cold mullion and condensation you saw.

That condensation doesn't do any harm, but if you're willing to pay for an extra 10 watts more, you can turn on the mullion heater and get rid of it. You do that by turning the Energy Saver switch to the OFF position.

It's a confusing system. They shoulda just called it a mullion heater switch so that "ON" meant power to the mullion heater. Then, people could figure it out by themselves.

Mine's actually labelled something like "condensation control", easily letting me figure it out for myself - even better than a "mullion heater" label, I think, since your average dude may not know what a mullion is. I just don't know a lot about refrigerators and didn't even think to look for a switch in the first place. Sometimes it's the simple things that are the biggest obstacles...

For me the extra energy consumption is worth avoiding mildew growing in our fridge.

This message has been edited. Last edited by: JKeefe,

Keep in mind that you don't need to keep your "condensation control" switch on "ON" all the time.

In the winter, or even come fall, you'll have lower indoor relative humidity, so you could probably flip your switch back without having to worry about the condensation returning, and save yourself a buck or two on your monthly electricity bill.

After all, if the problem only started happening recently, it could just be the recent high temperatures and associated high humidity that necessitated the need for heat at the mullion to prevent condensation forming there.

OK, so now you know. G'Luck with this.

This message has been edited. Last edited by: Nestor,