Relays Burning in Dometic Refrig

[lloyd&pamela]

The this is the second time the propane warning lights has come on and after inspection the relays behind the heat shield are burned and the wires melting. The first time was just prior to POG V and Rick May ordered the replacement relays and installed them. Everything worked fine until last week when I noticed the warning light was on again and after removing the panel found the following results in the photos.

Any suggestions on what the cause might be and possible solutions? Thanks.

[Jon Wehrenberg]

Lloyd....I never had a Dometic but from your photos it looks like that relay and the associated wiring is exposed to heat from the burner.

If I had to guess the relay itself is not heating up, but is getting hot from something around it. The wires are exposed to the same heat source from the looks of things.

I suggest operating it with the cover open to see if there is any visible indication of where the heat is coming from such as a burner out of place. Look to see if there are signs that a baffle or heat deflector has been removed.

Definitely see if the Dometic parts list shows a baffle.

You can keep replacing relays but the result will be the same. The simple solution is to relocate the relay to a cool location and lengthen the wires as necessary keeping them away from the heat, but it is highly unlikely Dometic made the product with the problem you have. Something has changed.

I'm not one for re-inventing the wheel so if it was me I would look around for other campers with the same refrigerator and see how their relay is mounted and protected before I did anything.

[lloyd&pamela]

from the schematics in the manual, everything seems to be connected correctly. Rick looked at the drawings also. The do sit quite close to the propane burner and he wondered why it was designed so close. I will contact Dometic this morning and see what they have to say.

I will also contact the local RV place through they are the ones that installed my tow lights and burned up the wiring so I have limited confidence there. If any one else has a Dometic and thinks the photos look incorrect please let me know. Thanks

[dalej]

Lloyd,

Be sure to check the flue, it has a wire at the top so you can keep it clean. You could have a partial plug in it, causing the flame to back out of the burner.

While driving down the highway you could be having the problem with the drafting.

The one photo showed some signs of a flame on the metal above the orifice. Run it while parked and make sure everything is cool to the touch i.e. relay, wiring.

The flame should be a nice blue with hardly no yellow.

[flyu2there]

Lloyd,

Dometic has a major recall on a number of propane combo refers. They have had several fires.....

Go to the dometic web site with your serial number and see if yours is one of them...seems to me that most were late 90's and early 2000 models but it would still be prudent to check.

John

[lloyd&pamela]

I will check the flue that could be the cause. I am trying to find someone around here that can fix it. Will have to wait till tomorrow, Victoria Day today. Thanks Dale.

[lloyd&pamela]

Thanks John, I will check that now.

[tdelorme]

--------------------------------------------------------------------------------
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 HAS NOT YET PROVIDED THE AGENCY WITH A NOTIFICATION AND REMEDY SCHEDULE. 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.

Link to the original topic: Dometic Refrigerator Recall

[lloyd&pamela]

Thanks Ted, I called and mine is not part of the recall. I have the name and number for a local service rep for Dometic and will contact them tomorrow, after the holiday, Victoria Day. Thank you,
Lloyd

[Ray Davis]

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

Yeah, I'm all too familiar with that.

The refer on the coach which caused our fire, as I understand it, was just outside the recall range. I guess someone forgot to tell that refer that it wasn't supposed to burn!

Personally, I would consider replacing the whole unit. But, that's just me.

Ray