Some have wondered why Dometic didn't install the lower wattage element as part of the recall. They should have, based on their comments as the reason for the original failures:
"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."
But it would have done no good. I think it was timsrv who wondered why a slight (within tolerance) heat difference should crack the boiler weld. He was correct, and Dometic was wrong, as shown by the the second recall which added units from June 2003 to September 2006 (all of which presumably had a newer 325 watt element).
Poor construction of all of the elements whether 354 watts or the later 325 watts (perhaps too hot a lower tip, hot spots, etc) may have contributed to the problem, but it appears that (as others have mentioned) the real cause of failure was metallurgical (wrong metals, weld, heat treatment...).
Perhaps Dometic figured it out. Anyone know how the 2007 - to - present units are holding up?
The Dometic refer in my 2001 Sierra which I just bought has hadly been used at all in the past 10 years, never had the recall done... works fine on gas andelectric but I decided to replace the 120V element and have the recall work done...
Replaced the element today with a new one, here are photos of the old and new element. They have done some redesign work as timsrv mentioned earlier....
edit: WTF can't use HTML to post photos? OK copy and paste time...
The old one measured 38.4 ohms, the new one 41.0 ohms... still too low with the 120 VAC here so I will install a light dimmer to lower the voltage (and wattage).
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10
CC, SB, Lariat & FX4 package
21,000 GCWR, 11,000 GVWR
Ford Tow Command
1,700# Reese HP hitch & HP Dual Cam
2 1/2" Towbeast Receiver
2004 Sunline Solaris T310SR
(I wish we were camping!)
For those that aren't sure where the serial number is on their double door Dometic, the tag is located on the upper side of the lower food compartment. The model, serial number and product number will be listed on this tag.
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