A step-by-step guide of how to quickly defrost a boat refrigerator for improved refrigerator efficiency.

Keys to Quickly Defrosting Your Refrigerator

One key to keeping your boat refrigerator running efficiently is to defrost whenever there is 1/4 inch of frost built up.  In the Sea of Cortez (surrounded by desert), I had to defrost about once a month. Now, in extremely humid southern Florida, it’s about once every 10 days.

This doesn’t have to be a huge chore – with a hair dryer and inverter (or shore power), I could defrost the large refrigerator on our previous boat in about 35 minutes.  (Be sure to read my notes at the bottom of this article if you don’t already have a hair dryer on board.)

It takes a little longer — about 45 minutes — on our current boat as the refrigerator manufacturer recommends not using a dryer because it could warp plastic parts inside the refrigerator. So even though the total time is longer, I’m not actually working on it the whole time.

In this age of frost-free refrigerators, many of us have never manually defrosted a refrigerator – or only have dim memories of mom doing it when we were a kid.  It took me a while to learn how to quickly defrost the refrigerator, so I didn’t dread having to do it.  It helps if all your food is already in bins.  If you’re in a hot climate, you have to work fast so that food won’t spoil.

Here’s my method:

  • Put your most perishable foods (frozen foods, milk) in the best coolers you have.  I like soft-sided coolers on the boat because they’re easy to store — the Polar Bear 24-can and 48-can coolers aren’t cheap, but really work well both for defrosting and getting stuff back to the boat from a distant store — if the items are already frozen, they’ll stay that way for a couple of hours even without extra ice if you’ve got a good cooler.
  • Take all your bins out of the refrigerator.  Quickly check to see if any need cleaning out, either from spills or spoiled food and take care of it now.   Cover the bins with quilts, towels, pillows, sweatshirts or whatever else you have to insulate the contents.
  • Turn off the refrigerator and remove all dividers.  If there is a drain in the bottom, open it (see my article on why the drain should be closed for everyday operation).
  • If you can, use a hairdryer to melt the ice build-up.  Be careful not to actually get the hairdryer in any water, due to the electrocution risk.  Many times, the hairdryer will cut off before all the ice is melted – this is a safety feature to keep it from getting too hot.  Turn it off for a few minutes and let it cool off, then use it again.
  • If you’re not using a hair dryer, it can help to point a fan at the inside of the fridge. After about five minutes, see if ice will start breaking off.
  • Break off chunks of ice from the chill plate as possible and dump them in the sink.  It is much easier to dry out the refrigerator if you don’t let them melt in the bottom of the refrigerator.
  • Be very careful around the chill plate or freezer compartment not to puncture a tube, but use a dull knife or piece of dowel to gently poke ice out of hard-to-reach places.  Never use force, as you’re likely to break something and then you’ll be without a refrigerator.
  • When all else fails, you can pour hot water over a stubborn bit of ice – but this will create a lot more work to mop it all out of the bottom of the refrigerator if you don’t have a drain.
  • Totally dry out the refrigerator, close the drain and replace any dividers before putting food back in the refrigerator.  Any moisture left in the refrigerator will quickly turn to frost and ice, necessitating another defrosting job.
  • EXTRA TIP from Debi on Facebook: spray the cool plate with cooking spray (like Pam) before you put everything back in. When you next defrost, the ice will come off much more easily and in big chunks! This has made it much easier for me and ensures that frozen food doesn’t stick to the compartment walls, either.
  • Don’t forget to turn the refrigerator back on!

A FEW NOTES ABOUT USING A HAIR DRYER ON BOARD:  If you don’t already use a hair dryer on board — and most cruisers have hair styles that don’t require one — there are a couple of things to consider:

  • Most blow dryers are 1875 watts, although most mini-dryers are 1600 watts.  Both are going to require a 2000-watt inverter and won’t work on the little inverters that plug into a cigarette lighter.  You can also run one off shore power or a generator that puts out at least 2000 watts.
  • I actually prefer using the mini dryers as the shorter nozzle is easier to use in the confines of a refrigerator and it’s easier to store.  You don’t need one with a lot of features — I bought the cheapest one I could find.
  • Try to find a dryer with a long enough cord that you don’t have to use an extension cord — or make sure that you’ve got an extension cord on board.
  • What’s the power draw to use a hair dryer on an inverter?  If you use an 1600 watt dryer on high for a total of 6 minutes (and if you keep the refrigerator defrosted regularly, I doubt if you’ll need to use it that long), you’ll use a little under 14 amp-hours from a 12-volt battery bank.  If you don’t have a lot of solar or wind-generation power, this can be a good project on a day when you’re going to be motoring a bit so that you’ll have plenty of power to replenish the batteries.
A step-by-step guide of how to quickly defrost a boat refrigerator for improved refrigerator efficiency.

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  • Debi
    Posted at 27 April 2011 Reply

    Spraying the cold plate with cooking spray (like Pam) will make your next defrosting much quicker and easier!

  • Sarah Schroeder
    Posted at 24 November 2011 Reply

    I use a fan. It is a drugstore purchase, about ten inches, plastic floor model with three speeds. I turn it on high and hold it so it hits pretty much all of the sections about twelve inches or so from the coils for five to ten minutes. If it is not time to do a full scrub down I do a “quickie” and put a thick towel on top of the food on the top shelf that catches most of the water and ice before it hits the bottom. Voila I started doing this when I realized the coils were getting heated up from the hair dryer and it took them too long to recoperate.

  • Jackie
    Posted at 28 November 2011 Reply

    I don’t have a hair dryer on board, but use the microwave instead!! I first empty the freezer and the shelf immediately below the freezer compartment and then spread a large trash bag over it and as far back and “up the wall” as possible to catch as much of the drippings and ice chunks as I can. Then I “nuke” about 2 cups of water close to boiling and put that into a small metal pan and put that into the freezer. I rotate 2 cups in the microwave, so when the next cup is hot I replace the cooler water and reheat it. I keep doing that and “helping” the ice off with fingers or carefully with a dull knife until the job is done. I put a sponge under the freezer compartment to soak up the melting water, but the plastic bag catches much of it too. I carefully take the bag out and “dump” it into the cockpit. (Putting the towel on the plastic is a good tip too. I might try that next time.) This whole process took almost as long to write as it does to defrost!!

  • Candy Ann Williams on Facebook
    Posted at 14 February 2012 Reply

    I have never heard of spraying the cold plate with Pam….what a smart idea!! Thanks!

  • Andy
    Posted at 17 April 2012 Reply

    Two items that are most useful on a boat are popsicle sticks and a turkey baster. I use a popsicle stick instead of a dull knife to break up the ice and never have to worry about a puncture. Then I extract most of the water that collects on the fridge bottom using the turkey baster and a small container. The baster also works great when cleaning seawater strainers.

    • Tony
      Posted at 20 January 2015 Reply

      Love it! You could also use the baster to squirt hot water on the ice in hard to reach places. I am beginning to think that most boats need two basters, one for the kitchen, and one for the toolbox!

  • Gloria Rooney
    Posted at 24 July 2012 Reply

    I am still in a marina, so I use a hose and water pressure to defrost my freezer with it’s 3 cold plates. It only takes a few minutes,with not too many chunks to pry off, and now that I have a submersible pump it is easy to remove most of the water! I am glad to see there are ways to deal with this when I am away from the marina hose in the not so distant future..

  • Steve O'Brien
    Posted at 04 August 2012 Reply

    Our freezer compartment has a drain with a foot pump, so I fill a 2 gallon bucket with hot water, if we have it, or cold if not, set it on the countertop next to the top entry freezer, and use a length of 3/8″ clear plastic tubing to siphon water from the bucket and run it over the freezer plate to melt the ice and frost, then pump the water out of the bottom of the freezer. Much faster than a hair dryer, takes just 5-10 minutes, and the freezer compartment stays cold, so recovery is faster too.

    • Carolyn Shearlock
      Posted at 04 August 2012 Reply

      Great way to do it if you’ve got a way to pump it out!

      Thanks for adding! -Carolyn

      • Cyndy
        Posted at 03 February 2017 Reply

        what if you used the “shake and pump” hose thing that you described in another article? I got 2, one for fuel and one for water, based on your recommendation. I’m needing to defrost (have been putting it off for over a week), now I feel ready to take on the task but I still think I’m just going to turn it off and let it sit for a little while first.
        Also, I have really thick (insulating) bath mats that I keep over the top of both top loading doors anyway so I put them on top of the food and then cover the whole thing with towels in the sink. I’ve never had anything thaw that way. The bath mats do double duty as dish drainers while I do dishes.

  • Stephanie Gardiner
    Posted at 21 March 2013 Reply

    Let me start by saying that we’re currently cruising in the Pacific Northwest where water temperatures are usually around 65 degrees in the summer (up to 77) and day time highs rarely reach more than 85 degrees. I’ve tried several methods for defrosting the frig and this is what works best for me: the night before I want to clean it, I turn it off. That’s it. When I wake up in the morning, I clear everything out, clean up the water, and turn it back on. Not only is it a great way to take stock of our fresh provisions, it saves about 20 amps (best guess). The whole process takes less than 30 minutes and I have to empty the frig/freezer regardless of the method I choose, so I might as well save amp hours rather than use them!

  • Shelly Young
    Posted at 17 November 2013 Reply

    Simple clamp on fan works for us in less than 30 minutes. Saves heating up a fridge/freezer that you are just going to cool down.

  • Kenneth Arnold
    Posted at 18 November 2013 Reply

    12 volt hair driers are avail., mine was $14.00 @ adventurerv.net

  • Mike Wilson
    Posted at 27 June 2014 Reply

    The frost on the plate comes from the humidity in the air. If your box seals are not up to scratch then you will get premature frosting. A real quick, cost effective and easy way to tackle this problem is to lay a thin soft, supple rubber sheet right over counter top/ box to make an airtight seal ! Just roll it back when you want into the fridge!

    MexiColder Mike

    Marine Refrigeration Engineer (Dip. Mech./Mar. Eng. U.K 🙂

    AKA Rescue Refrigeration Mazatlan Sinaloa Mexico

    • JAY
      Posted at 02 February 2017 Reply

      Maybe a bit off-topic…I recently had to replace gasket on refrigerator. To make gasket more flexible soak in HOT water before you install.

  • S/V Dos Libras
    Posted at 01 November 2014 Reply

    We still use the hair dryer to defrost our freezer, but find that if we just switch off the fridge before we go to bed at night, the ice will be melted by morning, maybe a few clinging chunks behind the plate… but then I just sponge it out of the bottom and turn the fridge back on. It doesn’t get warm enough to spoil food but I usually try to do it when there isn’t a lot of stuff in there.

  • Michael Mangione
    Posted at 02 November 2014 Reply

    If you save the ice off of the evaporator, then this water can be used to top off the batteries.
    We have made it to Marathon Key. Would love to meet up with you guys sometime.

    Michael and Robin Mangione
    S/V Sea Change

  • Kris
    Posted at 14 July 2015 Reply

    I use a fan because my manufacturer’s manual specifically says not to use a hair dryer to melt the frost. They also suggest that once the freezer is defrosted, turn the unit back on and let it get to temperature before returning the food to the freezer. This might add 15-20 minutes time before refilling the freezer and it works very well for me.

  • Louis Derry
    Posted at 30 September 2015 Reply

    Georgia Pike 😉

  • Sailing Banyan
    Posted at 30 September 2015 Reply

    Thanks for the idea of spraying with Pam, I think I may try that 🙂

  • Georgia Pike
    Posted at 30 September 2015 Reply

    We can do it on the weekend :-p x

  • Michael Mangione
    Posted at 30 September 2015 Reply

    Thrifty sailors can use the water from a fridge defrost to refill the water in lead acid batteries. The ice in the fridge has been deposited by sublimation– so it’s essentially free of any minerals. Just like distilled water.

  • Robin Moody
    Posted at 30 September 2015 Reply

    I use my AquaBot bottle sprayer filled with warm water to melt the ice off the hard to reach places! We have a drain so not a big deal using warm water.

  • Iain Fraser
    Posted at 01 October 2015 Reply

    If you don’t have a hair dryer (my hair style consists of grade 2 on the clippers!) you can boil the kettle and put bowls or plastic bottles of hot water in the freezer compartment. This works for my fridge with tiny ice box in one corner. Might not be so good for a proper fridge freezer.

    • Sheryl Shard
      Posted at 15 May 2016 Reply

      I often use a bowl of hot water to steam defrost the small freezer compartment in our Frigoboat front-opening fridge on Distant Shores II like Iain does. Another trick I use is to put in a few cans of unchilled beer or sodas into the freezer compartment which quickly melt the ice and cools the drinks 🙂

  • Emmanuelle Buecher-Hall
    Posted at 15 May 2016 Reply

    I use boiling water in bowls and close it. Takes 15min

  • Ed Robinson
    Posted at 15 May 2016 Reply

    Doing this chore today.

    • Sheryl Shard
      Posted at 15 May 2016 Reply

      Sunday is my day to defrost the fridge and freezer on our boat too.

  • Iain Fraser
    Posted at 15 May 2016 Reply

    Same as Emmanuelle…I use bowls of boiling water. Need to exercise care handling them but it defrosts nice and quickly….

  • Dave Skolnick
    Posted at 15 May 2016 Reply

    What is this “dull knife” of which you speak? *grin* All my knives are sharp.

    • The Boat Galley
      Posted at 15 May 2016 Reply

      Don’t you have a butter knife? I thought you were a sophisticated type of guy like that . . .

  • Sheryl Shard
    Posted at 15 May 2016 Reply

    Great tips for keeping the fridge in your galley working efficiently. Very helpful post, Carolyn! Thanks. I enjoyed all the comments and suggestions from your readers too.

  • Sheryl Shard
    Posted at 15 May 2016 Reply

    Warm cans of soda or beer also help melt the ice when defrosting a small freezer compartment and the process chills the drinks too. I often do this. Why waste that cold

  • Scott Berg
    Posted at 15 May 2016 Reply

    I used to sell ice box conversions
    Free ice pick with every sale! Works like magic for return business!

  • Annika Elias
    Posted at 17 May 2016 Reply

    If you would like to turn your existing fridge into one you don’t have to defrost I recommend checkign out the Fridge Optimizer. We have not defrosted in 3 years since we built the first prototype. Since we launched at Seattle boat show this year we now have happy customers too 🙂

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