Fixing a Norcold Refrigerator
Dave and Helen Damouth www.damouth.com
March 17, 1999
Ever since we acquired our 1988 trailer, three years ago, the Norcold model 8663 refrigerator has sporadically refused to operate on propane. Usually, the problem was that the flame would light, appear to burn normally, then go out after 10 seconds or so, refusing to start again until I cycled the control panel switch to "off" and then back to propane. In recent months, there has also been another failure mode, where the flame came on very weakly or not at all, and then blew out with a loud "pop".
Each time it failed, I did all the standard maintenance things, and it generally started operating just fine. Then, a few months later, it would fail again.
The maintenance items include:
Check that the flame is burning properly. Clean the orifice, if it hasn't been done recently or if the flame quality looked questionable.
Check that the ignition electrode and flame sensor were positioned properly.
Clean and/or re-seat the electrical connectors.
I should probably also have checked the gas pressure, but the flame looked normal when it was working right, and the other propane appliances seemed OK, so I just assumed that the pressure was fine.
Verify that the vents are unobstructed (not really relevant to this particular set of symptoms, but a good idea.
Verify that the trailer is level (again, not relevant to the particular problem I was experiencing, but included for completeness.)
In recent months, the problem gradually became more frequent until finally, I was lucky if the refrigerator would keep operating for a couple of hours. The failure seemed to happen most frequently in hot weather.
It took a long time to diagnose the problem, since almost any maintenance procedure seemed to fix the problem for a while. And we would also have long periods when we were always staying in campgrounds with electricity, and the propane mode was only used while driving. I thought for a while that the failures while driving had something to do with wind blowing out the flame.
Finally, a couple of weeks ago, the problem was causing us enough inconvenience so that I decided to fix it with the good old "replace something and hope" technique, just like the professionals <g>
I decided that the most likely explanation of the problem was that the sensitivity of the flame ignitor module had become insufficient to reliably detect the small current from the sense electrode. The other, less frequent, problem seemed caused by the gas valve not turning on all the way (weak flame). The electronic switch which applies power to the valve is also in the ignitor module, so replacing this board might fix both problems at once. (Or perhaps the solenoid- actuated valve itself would prove to be mechanically defective).
Several people on the Internet have raved about the quality of replacement electronic boards for RV appliances manufactured by Dinosaur Electronics. I checked the Dinosaur web site, and found that they did not make specific boards for the Norcold, but did make a "Universal Ignitor Board" that seemed to be a functional replacement that would work properly in my Norcold. Dinosaur will not sell direct to end users. But their Web Site pointed me to a couple of RV parts businesses on the Internet that were Dinosaur dealers One of these, Mark's RV Supplies, had additional information about this board, which convinced me it really would work in my application.
But wanting instant gratification, I first checked with a local dealer in Harlingen, Texas, recommended by our campground manager. This dealer indeed had all four models of the UIB (electronically identical but differing only in mechanical details) in stock. They also had a convenient plastic cover in which to mount the new board (the old board was sealed into its cover, and it wasn't clear that the old cover could be re-used. As it turns out, I could have used it, with some minor surgery. I paid $124 at the local store, including a $5.50 plastic cover and sales tax. The Web Site for Mark's RV Supplies listed the board at $100 (plus shipping).
Installing the new board took about 10 minutes. The only tools needed were a Phillips screwdriver, a wire crimping tool (or soldering iron), and a small wire cutter. The sense wire was soldered to the old board. The new board provided a standard spade lug, so I crimped a matching connector to the old sense wire.
The board contains two jumpers which could be cut to select particular options. One selects an external flame sense electrode, which I had, so I cut this jumper. The other jumper selects the restart mode. As delivered, the unit will try three times to start the flame. (Initially, when power is applied, the board does nothing for 20 seconds (this is for use in furnaces, where the fan should run for 20 seconds to purge any gas, before lighting the flame). Next, it turns on the gas and begins sparking. Then, if it hasn't detected a flame within 6 seconds, it shuts down, waits 20 seconds, and then tries again. After three tries, it gives up. Cutting a jumper will reduce this to a single try, which is the way the original Norcold electronics works. Somewhere in the literature is a comment that the single-try mode is for refrigerators and the three-try mode is for furnaces. I've left it in the three-try mode. I don't see any disadvantage or safety issue, but I'll probably Email Dinosaur and ask them about it.
With the new board, the refrigerator has now been working flawlessly for 10 days. I am optimistic that the problem has been completely cured.
Internet links for the replacement board:
Dinosaur Electronics (the manufacturer)
Mark's RV Supplies (an Internet dealer)
Well-stocked RV parts and repair shop in Harlingen, Texas:
RV Mobile Home Center
1713 S. F Street
Harlingen, TX 78550
(210) 425-1986