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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Travelin' Man (RIP) on January 15, 2016, 12:36:07 pm

Title: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 15, 2016, 12:36:07 pm
Does the Dometic 1492 reefer have a defrost cycle in the board or do I need to defrost it the old-fashioned way?
Title: Re: Dometic 1492 Question
Post by: Jim Frerichs on January 15, 2016, 01:11:41 pm
T-Man,

The 1492 must be defrosted the old fashioned way.

Jim

2002 U320
Title: Re: Dometic 1492 Question
Post by: Mike Leary (RIP) on January 15, 2016, 01:48:37 pm
T-Man,

The 1492 must be defrosted the old fashioned way.

Jim

2002 U320
AND, if it's like our Dometic  3692 ( 2009), it drains into a small can, rather than daylighting. We don't need that!
Title: Re: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 15, 2016, 05:33:30 pm
Is there an after-market solution that will allow it to go into defrost mode, or is that not a possibility?
Title: Re: Dometic 1492 Question
Post by: wolfe10 on January 15, 2016, 05:51:48 pm
May be some confusion here.  The REFRIGERATOR condensate has a drain.  The FREEZER does not. 

So, yes, you need to defrost the "old fashion" way.

Easiest way:

Turn off the refrigerator.  Wait 1 hour in summer, 2 hours in winter.

Remove everything from freezer-- put in an ice chest or cardboard box...

Open both refrigerator and freezer doors.

Use a hair dryer on LOW from OUTSIDE the freezer to melt the ice.  Same with fins in the refrigerator.  Do not overheat either.

You will need a work towel in the freezer to capture the water.  If not stopped up, the refrigerator condensate will go out the condensate drain.

Total time should be less than 15 minutes of work-- if longer, do it more often (ice is a GREAT/too good an insulator).
Title: Re: Dometic 1492 Question
Post by: Jim Frerichs on January 15, 2016, 07:41:34 pm
T-man.

That refrigerator was not designed to self defrost...sorry. Be sure not to use a hot hair dryer to defrost it. You would be surprised how destructive the coils are to excess heat. Best to put a regular fan in the lower areas and let it run with the door open for several hours. Check to see that the drain plug is removed at the bottom, back of the refrigerator compartment.

You might try setting the cooling level to a lower setting - surprisingly it cools just as well there and usually builds up a lot less ice. The other" very important trick" is do not to put food against the back wall of both compartments, circulation is needed to cool properly. Also many people install little 12 volt fans to blow on the refrigerator coils to cut down on the amount of frost that wants to accumulate.

Jim
Title: Re: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 15, 2016, 09:06:25 pm
Jim,
what kind of time frame for defrosting is normal?  I've only been running the reefer for nine days now and the fins are iced up pretty heavily to a point almost half-way up from the bottom.

The Norcold 1200 that I had prior to this I made a bank of muffin fans for that went across the entire width of the fins.  I'm remembering five fans total, and they worked great.  Do they market a bank of fans for the 1492 or do I need to put my own together?
Title: Re: Dometic 1492 Question
Post by: Jim Frerichs on January 15, 2016, 11:03:43 pm
Hi T-man,

Defrost time will depend upon how much ice is present and how warm the ambient air is. Just place a household fan in the refrigerator section, have it blow upward and leave the door wide open. It could take several hours.

I suggest that you look on EBay or Amazon for several small fans mounted on a frame.

Jim
Title: Re: Dometic 1492 Question
Post by: Michelle on January 16, 2016, 06:53:46 am
Do they market a bank of fans for the 1492 or do I need to put my own together?


Check the "Renovations" board for some fridge fan ideas.  There are several options, both DIY and "purchase from eBay".  Forum search for fridge fans should bring the threads up.
Title: Re: Dometic 1492 Question
Post by: Carol Savournin on January 16, 2016, 08:01:59 am
My 1492 in our "02 was the side-by side ... I guess they all are configured that way. My freezer compartment had a drain in the bottom. I put the ice bin in the fridge compartment during the "defrost" period when the fridge was turned off, to help keep the items there at a safe temp. the frozen goods went into a garbage bag that then went into a laundry basket that had been lined with throw blankets. We never traveled with a cooler big enough to hold all that freezer stuff. Wrapped in a few layers, they never suffered any melt-down. I used the hair dryer method to loosen and melt the ice. Be sure that the ice behind the metal plate in the back is gone, as well.  I knew all was good when there was no more dripping collecting at the drain. Quick wipe and all was turned back on. I HATED that fridge. I never knew why it would up ice so fast! I checked and re-checked and cleaned the gasket ... it was in great shape and held a good seal. I had to defrost about every other week!! I am totally happy with my residential model now. One of our best upgrades.
Title: Re: Dometic 1492 Question
Post by: rsihnhold on January 16, 2016, 09:13:34 am
Jim,
what kind of time frame for defrosting is normal?  I've only been running the reefer for nine days now and the fins are iced up pretty heavily to a point almost half-way up from the bottom.

You can buy some of the remote thermostats like this and only need to defrost when they can't maintain the temperature anymore, probably about once a month or so.

Amazon.com - AcuRite 00986 Refrigerator/Freezer Wireless Digital Thermometer... (http://www.amazon.com/AcuRite-Refrigerator-Freezer-Wireless-Thermometer/dp/B004QJVU78/ref=sr_1_28?ie=UTF8&qid=1452952696&sr=8-28&keywords=wireless+thermometer)
Title: Re: Dometic 1492 Question
Post by: Horace B. Cupp on January 16, 2016, 10:25:37 am
T-Man, icing up on the coils in your fridge is caused by having the fridge too cold. Warm it up to 39-43 degrees and the icing will stop.
Title: Re: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 16, 2016, 11:24:24 am
Jim,
what kind of time frame for defrosting is normal?  I've only been running the reefer for nine days now and the fins are iced up pretty heavily to a point almost half-way up from the bottom.

The Norcold 1200 that I had prior to this I made a bank of muffin fans for that went across the entire width of the fins.  I'm remembering five fans total, and they worked great.  Do they market a bank of fans for the 1492 or do I need to put my own together?

Hi T-man,

Defrost time will depend upon how much ice is present and how warm the ambient air is. Just place a household fan in the refrigerator section, have it blow upward and leave the door wide open. It could take several hours.

I suggest that you look on EBay or Amazon for several small fans mounted on a frame.

Jim

Sorry for the confusion......................what I meant was normally how often should defrosting be necessary?

Last night about 8:00 PM I shut the reefer off and by about 1:00 AM this morning the ice was gonzo.
No problem with drainage as the hose runs through the floor. 
Title: Re: Dometic 1492 Question
Post by: Roger & Susan in Home2 on January 16, 2016, 11:29:57 am
Fridge fans helped with ice build up and more uniform temps but if your fridge is on for months at a time you will have to do a manual defrost (maybe every 1-2 weeks).  That depends quite a bit on outside humidity. Watch the drain tray and line under the cooling fins in the fridge aide.  You can get ice in there that stops the drain.

We did the residential fridge replacement.  If you are a hard core boondocker this adds to your power requirements. But we like Carol think it has been the best upgrade we have done.

Roger
Title: Re: Dometic 1492 Question
Post by: Mark D on January 16, 2016, 11:37:54 am
I've found with ours over the years that there is a setting that you can keep things at where you will get maximum cooling without adding more fans.  Our fridge is around 41-42F and we get no ice buildup.  This is with the second to warmest cooling setting.  A layer of frost will build up during the day as the fridge is opened but it will melt and drain overnight.  If we set it to the middle setting ice starts to slowly build up in the fridge.  I don't know if this is technically cold enough for food safety but our food doesn't seem to go bad and the food feels pretty cold.

We don't like to remove our food or risk spoilage when defrosting.  Our way to deal with the ice buildup, what we do is turn the fridge off and leave it closed.  Once an hour or so I come by and check to see if the ice block has loosened from the fins.  At some point it will be a loose chunk that you can remove in a few large pieces.  As long as there is an ice block in there it won't warm up much.  Your food stays fine and you don't need to remove much to get the ice block out.

The freezer is more complicated.  Ours builds up ice regardless and eventually when the ice prevents the door from closing properly we defrost.  Ours if the vertical door wide model.  We usually unload the freezer food into the basement freezer during this process.
Title: Re: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 16, 2016, 11:53:55 am
In our last rig we had a Norcold 1200.  When the cooling fins iced up and it went into defrost mode the ice water ran down
onto the bottom of the reefer, through the door seal and onto the kitchen floor.  It was almost like a design flaw where the drip tray did not extend to each end of the cooling fins.  I got lucky and solved the problem with dry sponges stuffed into the voids at each end of the fins.
Title: Re: Dometic 1492 Question
Post by: Michelle on January 16, 2016, 12:44:33 pm
I've found with ours over the years that there is a setting that you can keep things at where you will get maximum cooling without adding more fans.  Our fridge is around 41-42F and we get no ice buildup. 

Be aware that 40-140F is the "danger zone" for bacteria growth, with 4 hours maximum total time in this range for high perishable foods.  USDA advises fridges should be kept below 40 for food safety.
Title: Re: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 16, 2016, 12:49:04 pm
Love my steaks @ 140F!
Title: Re: Dometic 1492 Question
Post by: Michelle on January 16, 2016, 01:34:13 pm

Yeah, but BIG difference between internal temperature and storage/cooking temperature.  ;)

Danger Zone (http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/danger-zone-40-f-140-f/CT_Index)
Title: Re: Dometic 1492 Question
Post by: Horace B. Cupp on January 16, 2016, 02:17:49 pm
T-Man.
I was having your problem as well. I set the numerical temp button on "2". I then adjusted the slider on the last right fin so that my fridge temp stayed at 38 degrees overnight. I had no more frost on the fins. The freezer, however, continued to frost up and required defrosting every couple of weeks. I am told this is due to the water in the ice- maker.
Title: Re: Dometic 1492 Question
Post by: wolfe10 on January 16, 2016, 02:22:23 pm
Sorry for the confusion......................what I meant was normally how often should defrosting be necessary?

Last night about 8:00 PM I shut the reefer off and by about 1:00 AM this morning the ice was gonzo.
No problem with drainage as the hose runs through the floor. 


Yes, the REFRIGERATOR condensate should drain easily (unless the drain hose is clogged).  Also, be sure to leave the "restrictor" in the outside end of the condensate drain hose.  If left open it is a "straight run up (heat rises) for outside air to enter the refrigerator-- a certain receipt for frost.

But, the FREEZER section of many absorption refrigerators does not have a condensate drain and you must use a work towel, sponge, etc to remove the water.

I will repeat the caution on using a hair dryer to defrost (same as above):  ONLY on low and ONLY with the hot end outside the refrigerator.  As Jim pointed out, get carried away with a heat source and warp the plastic of the refrigerator-- NOT GOOD.

There is no "here is how often to defrost based on time":  Humid or dry climate, open it once a day or 25 times a day........

My suggestion is to defrost when the ice on the cooling plate in the freezer is over 1/4" thick.  Ice is an excellent insulator and a thick coating of ice will materially hamper heat transfer.
Title: Re: Dometic 1492 Question
Post by: Travelin' Man (RIP) on January 16, 2016, 03:00:06 pm
Yes, the REFRIGERATOR condensate should drain easily (unless the drain hose is clogged).  Also, be sure to leave the "restrictor" in the outside end of the condensate drain hose.  If left open it is a "straight run up (heat rises) for outside air to enter the refrigerator-- a certain receipt for frost.

Some installs have a loop in the drain hose to act as a trap. 
Title: Re: Dometic 1492 Question
Post by: wolfe10 on January 16, 2016, 03:21:26 pm
Some installs have a loop in the drain hose to act as a trap. 
Yup, a P trap accomplishes the same thing.  Bottom line- you want water to flow out, but absolutely do not want air flowing in!