Dometic Refer Recall - Possible Fire Hazard -Update 2/13/07

[MELM]

Click here to go directly to Updates.
Update Number 1 Nov 23, 2006
Update Number 2 Dec 5, 2006
Update Number 3 Jan 10, 2007
Update Number 4 Jan 19, 2007 - Recall Instructions - click here: Dometic Recall You need your model and serial numbers.
Update Number 5 Feb 13, 2007 - Added links to new info on the NHTSA website including the info/form for claiming reimbursement for a failure. These are at the end of the post below where all the updates are posted.

Also, edited the below Recall to include the change made prior to the Dec 5 update showing the proposed remedy.

Below is information from the NHTSA website on a recall of certain Dometic refrigerators. This recall is in its very early stages, and there is no resolution in place as of Nov 1, 2006.

From the NHTSA website:

Dometic Recall NHTSA Campaign ID 06E076000

Make / Models : Model/Build Years:
DOMETIC / NDR1062 9999
DOMETIC / RM2652 9999
DOMETIC / RM2662 9999
DOMETIC / RM2663 9999
DOMETIC / RM2852 9999
DOMETIC / RM2862 9999
DOMETIC / RM3662 9999
DOMETIC / RM3663 9999
DOMETIC / RM3862 9999
DOMETIC / RM3863 9999

Manufacturer : DOMETIC CORPORATION

NHTSA CAMPAIGN ID Number : 06E076000 Mfg's Report Date : AUG 28, 2006

Component: EQUIPMENT: RECREATIONAL VEHICLE

Potential Number Of Units Affected : 926877

Summary:
CERTAIN DOMETIC TWO-DOOR REFRIGERATORS MANUFACTURED BETWEEN APRIL 1997 AND MAY 2003: SERIAL NOS.
713XXXXX THROUGH 752XXXXX;
801XXXXX THROUGH 852XXXXX;
901XXXXX THROUGH 952XXXXX;
001XXXXX THROUGH 052XXXXX;
101XXXXX THROUGH 152XXXXX;
201XXXXX THROUGH 252XXXXX;
301XXXXX THROUGH 319XXXXX,
INSTALLED IN CERTAIN RECREATIONAL VEHICLES AS ORIGINAL EQUIPMENT AND SOLD AS AFTERMARKET EQUIPMENT. A FATIGUE CRACK MAY DEVELOP IN THE BOILER TUBE WHICH MAY RELEASE A SUFFICIENT AMOUNT OF PRESSURIZED COOLANT SOLUTION INTO AN AREA WHERE AN IGNITION SOURCE (GAS FLAME) IS PRESENT.

Consequence:
THE RELEASE OF COOLANT UNDER CERTAIN CONDITIONS COULD IGNITE AND RESULT IN A FIRE.

Remedy:
THE VEHICLE MANUFACTURERS WILL NOTIFY OWNERS OF RECREATIONAL VEHICLES THAT HAD THE REFRIGERATORS INSTALLED AS ORIGINAL EQUIPMENT AND DOMETIC WILL NOTIFY OWNERS OF THE AFTERMARKET REFRIGERATORS. DOMETIC WILL INSTALL A SECONDARY BURNER HOUSING FREE OF CHARGE. THE RECALL IS EXPECTED TO BEGIN BETWEEN APRIL AND JUNE 2007. OWNERS MAY CONTACT DOMETIC AT 888-446-5157.

Notes:
CUSTOMERS MAY CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S VEHICLE SAFETY HOTLINE AT 1-888-327-4236 (TTY: 1-800-424-9153); OR GO TO HTTP://WWW.SAFERCAR.GOV.

The following is extracted from the notice provided by Dometic to the NHTSA dated 8/26/06:

The potential defect is associated with cooling unit at the back of the refrigeration cabinet.

A fractional percentage of the potentially affected refrigerators have experienced a fatigue crack that may develop in the boiler tube in the area of the weld between the boiler tube and the heater pocket. A fatigue crack may release a sufficient amount of pressurized coolant solution into an area where an ignition source (gas flame) is present. Dometic's investigation has shown that a simulated release of cooling solution (refrigerant) in the area of the boiler, under certain conditions, could be ignited by the presence of an open flame. A boiler fatigue crack with the loss of cooling solution without ignition would result in a non-operational refrigerator that is not a safety issue. Under certain conditions, the released coolant could ignite and result in a fire. In order to have a fire, at a minimum, all of the following conditions must exist:

1. The refrigerator must be on and normally operating and gas burner must be lit;
2. 'There must be an oversized heating element in the refrigerator;
3. The boiler tube must develop a throughway fatigue crack of a
specific size;
4. There must be a release of the cooling solution at a rate which will
allow the accumulation of the cooling solution at a concentration within its range of flammability; and
5. There must be ignition source (gas flame) present.

If any of these conditions are not present, a release of the cooling solution will not result in a fire.

In April of 1997 Dometic modified the design of the affected refrigerators by increasing the wattage of the heating element from 325 watts to 354 watts. All production of the affected units from April 1997 through May of 2003 utilized the 354 watt heating element. In May of 2003, in order to improve the operating life of the refrigerators, Dometic returned to the use of the 325 watt heating element which it continues to use today. It is now believed that the use of the higher wattage heater contributed to abnormal fatigue in the boiler tube.

The products in question are all refrigerators used in the original manufacture of recreation vehicles or as replacement equipment for recreation vehicles. The total population of refrigerators potentially containing the defect is 926,877. Dometic estimates a potential maximum incident rate of 0.01% related to boiler fatigue cracks that leak and may result in a fire. There have been no incidents of injury or death related to the affected population of Dometic refrigerators.

Dometic became aware of the occurrence of fires which may have involved their products and retained an independent engineering testing laboratory to fully evaluate and investigate any potential defect in their refrigerators which might result in a fire. A number of returned units were analyzed and microscopic fatigue cracks which could release coolant into the area of the burner were identified in the boiler tube metal in the area of the weld between the heater pocket and boiler tube. Tests simulating the cracks were conducted the week of August 18, 2006 and confirmed a possible cause of fire in the refrigerators under certain conditions. These test results prompted the preparation of this notice.

Dometic continues to gather information on the potential defect and will forward additional relevant information as it becomes available.

Dometic has not yet identified a proposed remedy for the potential defect. Dometic will continue a testing program designed to identify and evaluate possible remedies. This evaluation will take place both in the United States and in Sweden. Once a remedy has been identified, Dometic will initiate or participate in a remedy campaign initiated by the original equipment manufacturers and aftermarket suppliers who have purchased, sold, and distributed these products. A list of original equipment manufacturers and aftermarket suppliers to whom Dometic has sold the potentially defective refrigerators is being prepared and will be provided to the NHTSA upon its
completion.

The following is extracted from the NHTSA response on 9/18/06:

Please provide the following additional information and be reminded of the following requirements:

Dometic must provide an estimated dealer notification date as well as an owner notification date including the day, month, and year. You are required to submit a draft owner notification letter to this office no less than five days prior to mailing it to the customers. Also, copies of all notices, bulletins, dealer notifications, and other communications that relate to this recall, including a copy of the final owner notification letter and any subsequent owner follow-up notification letter(s), are required to be submitted to this office no later than 5 days after they are originally sent (if they are sent to more than one manufacturer, distributor, dealer, or purchaser/owner).

Dometic must file a sample of the envelope which you intend to use to mail the recall notice to owners. The words "SAFETY", "RECALL", "NOTICE" in any order must be printed on the envelope in larger font than the customers name and address.

[lotto38]

Call Dometic on 2/11, have not received anything as of yet. I am trying to call them back, but the call center has a large volume, and says to try again later.
Won't have the treialer out until April 1, but would like to get the ball rolling as soon as I can.

[WilleyB]

Villa wrote:
I can't believe that Dometic put these in with the stamp of 325 watts. Isn't that a little deceptive? And further more, they are not planning to replace the element that they claim is at the root of the issue.

Hi Villa, well I have no problem believing it at all. If they didn't know, then I'd like an explanation as to why my parts list reads 17374228/9 Heater 325W, 115V and the original element is marked 325W 120V. So someone at Dometic made a decision. Also the new heater element is different in construction, so there may have been a change of manufacturer.
The manual goes on to list RM 3663 RM 3862 RM 3863 as having the same elements. The way I see it, and have come to believe, is that they accepted a batch of below tolerance elements (for whatever reasons)and installed them believing all would be well. After all whats a couple of ohms between friends. If not why did they change the reference to the element in the users manual. Try buying an element with the above part number and watch all the changes to a new number. Yep the new element will be 120v 325w and 44 ohms resistance, one oddity here is the package it came in was marked 115v 325w figure that one out.

Wayne wrote:
Type 1 -- Dometic’s published rate of 0.01% is for the risk of a fire,

OK Wayne, that makes sense. It's not hard to believe that by far the majority of failures would be while the units were on 120vac and didn't result in fire. If the metal around the boiler weld was stressed enough through electrical operation, and was ready to break any time, then yes failure could occur while operating on gas. Mine fridge being in a camper most likely spent a lot of time running on LP

Dometic’s recall, so far as I can tell, deals only with failure Type 1. Their “fix” will prevent the refrigerant mix from catching fire if/when it leaks.

Yes, I'll certainly agree to that, and will have the "fix" done because I have no idea of how much the unit was used on AC and without an x-ray would have no idea of the weld condition.
With the new element operating, hopefully within specifications, the best I can hope for is that further deterioration will not take place in the weld area and the unit will not fail during my ownership.
(well I can hope can't I? ;))
I wonder what the real failure rate is due to the broken weld.

Willis

[Villa_on_Wheels]

For those who have pulled the electric element and read 325 watts imprinted on the rod...don't be fooled. I almost was, then upon reading more posts, I used an ohm meter to check the resistance. Per the Dometic specs in their own documents, it should show 44 plus or minus 10%. My element is stamped at 115 volts and 325 watts, however, 38.3 ohms....making it a 354 watt.

I am going to replace it with a new element and then do the recall as a preventative measure.

I can't believe that Dometic put these in with the stamp of 325 watts. Isn't that a little deceptive? And further more, they are not planning to replace the element that they claim is at the root of the issue.

Again, don't be fooled by the stamp on the element!

[Empty_Nest__Soo]

WilleyB wrote:
. . . A big question in my mind "Why such a low failure rate?" . . .

Hi Willis,

I suppose that depends upon what one calls a “failure.” I see at least two types:

Type 1 -- Dometic’s published rate of 0.01% is for the risk of a fire, perhaps only those that have/will spread to the house. That is a low rate, thought the potential loss is quite serious for the unlucky few.

Type 2 -- A separate concern is the rate of failure of the unit where it leaks its refrigerant mix without fire. I’m not sure anyone knows the true rate for this “failure.” This type is not life-threatening, and therefore not subject to a safety recall.

Dometic’s recall, so far as I can tell, deals only with failure Type 1. Their “fix” will prevent the refrigerant mix from catching fire if/when it leaks. Their “fix” will do nothing to prevent what appears to be an abysmally high rate of unit failure due to leakage. Am I wrong?

It appears that an essential element causing the failure is the too-hot electrical element.

Is this a design flaw? Poor testing/quality control? Other? I wager we will never know.

Whatever the cause of the too-hot element, I think it reflects very poorly upon Dometic that

1) this continued for so many years, and

2) their recall will do absolutely nothing to mitigate the likelihood of an early failure for those which have not yet caught fire.

It seems to me that at a minimum, Dometic should also replace the defective electrical heating elements as part of the recall, rather than letting hundreds of thousands of units risk a premature failure.

Wayne

[WilleyB]

John wrote:
We keep it up and we may actually understand the real problem. We are in lack of a good picture of the boiler tube area where the crack is located.

Hi John, while reviewing the thread there's little doubt in my mind that the culprit is two fold. I do believe between Dometic's recall paper, only fridges with the underrated element (354w???),Tim's post about the common factors to the failures was the underrated heating element and that it failed at the first weld above the elbow, plus Chris' post on the effect of stress from heating the weld.
A big question in my mind "Why such a low failure rate?"
There's also no doubt in my mind that a lot of failures happened but for reasons unknown (not reported)are not included in the statistics. Yet theres much reason to believe the failure rate is still low.
Now here it gets kind of iffy, Chris most likely could explain this better.
Those who have welding experience will understand there is a quality of weld depending on the penetration (mix of new metal to the pieces being welded)when heated the stress characteristics of this welded joint are quite different to the surrounding metals. It's easy to believe that a lower number units might have a much deeper weld penetration than the rest (new or novice welder)and when overworked by an excessive expansion and contraction, the weld will break from from one of the metals that were joined leaving a very weak structure.

No matter which parts list you look at the parameters for a 325 watt element is 44 ohms +/- 10% if your fridge has that it's not on the recall list. There is a reason for this, an absorption refrigerator must have the correct heat to operate. The low end tolerance is 39.6 ohms, so it is safe to assume this would generate the hottest allowable temperature and the expansion and contraction factor does not overwork the weld.

Now what I know from my refrigerator. It was put in service May 2000 in a RV rental unit five years before I bought it. The element I removed, was stamped 325w at 120v, however the element itself measured only 38.5 ohms. This is certainly much below tolerance and capable of heating and working the weld beyond the normal expansion caused by a true 325w element. Unless it's the quality of the weld that has prevented failure I have no idea. Also this may be true of the majority of units out there

Did Dometic know these elements were out of the +/-10% tolerance, of course they did, they printed the parts list to read 115v 325w so now it's back in tolerance. ( I have the parts list and the element, they can explain the rest)

The Dometic modification to the best of my knowledge, from what is posted on this thread, consists of a fix so that the unit does not catch fire when the cooling unit fails while operation on LP gas.

So What to do. I don't know about anyone else but here's my reaction.

1 Replace the heating element with a new one of correct specifications (preventative, why push one's luck)
2 When the Dometic fix is ready, have that done (Safety, it's free why take a chance)
3 When we have enough information I will install the thermal cutoff. (more safety, it's easy to do so why not)

Because of the thread I believe we have a better understanding of the problem and remedial actions we might take. At least now when we go out for a run I'll feel a lot better about it all than when the thread first started.

Cheers Willis

[rsg33]

This is the wiring diagram from the users manual. The blue arrow shows the device marked "L"

[JBarca]

Willis

That website you liked us to is GREAT!:) Thanks

For those that want to know how the actual fridge works, see this page. It is the most complete and simplest version I have found explaining how the absorption fridge actually works. Actually the phrase, "An experiment in gas laws" does come to mind when reading it....

How the Fridge works

Also doing some more digging, see here on the Dometic site for an animation of one working. Dometic - How Absorption Works (You have to click it to start it)

Balvat,

And a big thank you to you too. 🙂 After your lead, I went to the Dometic site and downloaded the new manual for my RM2652. The Cutoff thermostat, called a "Thermofuse" by Dometic, shows in the parts list wiring diagram. RM2652 Parts list BUT does not show up in the users manual wiring diagram. RM 2652 user Manual

So all the literature is not up to date yet. And I could not find the "thermofuse" listed as a spare part. But did find reference to the "Thermofuse" as part of the actual cooling unit assembly on some other models. Like on this http://www.dometicusa.com/pdf/3309836.009[1].pdf It shows up on page 12. (I can't get it to hot like with the [1] inside the link from Dometic. Will have to cut and paste.)

This may fit with what TimsRV was saying that it is not available as a spare part as he was told. It's like you only get it when you buy the entire cooling unit...:h I would hope that is not the case as if it is, well the aftermarket trail is where I'm heading.

Again thanks to all for sharing. We keep it up and we may actually understand the real problem. We are in lack of a good picture of the boiler tube area where the crack is located.

John

[WilleyB]

I can see HOW to Install it but what about the wiring in the picture above it shows the thermostat connected the the (Flue?) but it does not show where the wires should be hooked up to...

Hi Lee in Calif
Have a look at the diagram in this link. Note the block at the bottom labeled 12Volt(+) and the black wire from it. This is the line to be interupted by the thermal switch. One wire from the thermal switch goes to the (12Volt(+)) terminal and the other wire from the thermal switch would go to the (J4)terminal on the board.
Dometic Electrical Diagram
Hope this helps you in understanding the circuit.

Willis

[balvert]

Go to the Dometic website and download the User/Installation Manual for your reefer. This is my NDR2610. The wiring is generally the same among the models. Near the back of the manual you will see a wiring diagram. The thermal cutoff device is wired into the 12 power source to the control board. Item "W". Basically what happens is when the flue gets too hot (such as when the refrigerant leaks out) the thermal cutoff disconnects the 12 volt power to the board. This cuts off both the gas and AC power to the electrical element.

[Just_Lee]

I have been reading with great interest... My Fridge is one that is involved but I have seen no signs of leakage... My question is what about us dummies out here that do not understand all this talk about disk thermostat with manual reset and stuff? Are these easy to install? I can see HOW to Install it but what about the wiring in the picture above it shows the thermostat connected the the (Flue?) but it does not show where the wires should be hooked up to.... Or did I miss something... Which would not suprise me.....

[balvert]

I find it interesting that Dometic won't even sell the service people these things. Sure makes me wonder about their business ethic. As soon as I find out what these things are rated at, I will be installing one. At least it adds some bit of reassurance when I operate the thing.

[JBarca]

After doing a little digging, it "appears" we are looking for a disk thermostat with manual reset.

What we need to figure out is the temp trip point. Too low and we get false trips. Or a manufacture number off of Rsg33's that he so graciously helped us with a pic of. As a last resort I can go operate mine on electric and then propane and read the surface temp of the sheet metal and then know to add from there.

Going to the industrial world here are 3 manufactures of these types switches. My worries about current capacity are quickly dissolving. These can come with 15 amp inductive load ratings.

Selco 1/2" disk Thermostat And the cut sheet on them Selco catalog cut sheet

And here is a another brand Thermtrol and there cut sheet Thermtrol Disk Thermostats

And here is another brand Klixon brand disc thermostats and the data sheet
Klixon fixed temperature thermostats data sheet (The PDF file is large and takes a while to load)

Ideally one would want to use the same one Dometic is using. And even buy it from them. I'm out of any warranty so it's all mine right now and adding a thermal cutoff switch is purely a choice. Just like when I go to the local NAPA store to buy parts for my GM truck.

I'm not recommending anyone do anything with their unit, just passing along some investigation I have found.

Hope this helps

John

[Dusty_R]

If one could get the rating off it I would think they could get one from some where else.

[timsrv]

When I first noticed those about a year or so ago, I decided I should stock one for my business. I tried adding one to my next Dometic Direct order, but was told they were not available for purchase. I'll ask again next time I order & let you guys know. Tim

[balvert]

Now we are getting somewhere, Got to get a part number. 😉 I downloaded their latest parts manual for my NDR1062 and it doesn't show a thermal cutoff. However the new User Manual does show one but makes no reference to it in the text. I did a web search and found similar devices but don't have a clue what the rating is for the one Dometic is using.