Norcold 3163 3-way refrigerator won't start on propane, what fixed mine & general diagnostic advice

rajamar

If you have not experienced it yourself,I'm sure you have noticed the many threads talking about the problem of not being able to get the 3-way refrigerator started on propane. The burner will start - you can hear the spark clicking and the poof of the burner starting - with a little contortion or a helper you can peer back at the burner box and see the blue flame through the little circular window, but regardless of the position of the thermostat knob and no matter how slooooooowly the safety valve button is released the green light blinks off and the flame goes out.

We have been struggling with this issue for nearly 6 months. A few days before our maiden trip in March with our new-to-us 2016 320S we cooled down the refrigerator on AC, switched it over to propane and let it run overnight - it worked fine. Did the same thing the night before the trip and did the 5 hour trip to the coast (Wright's Beach, Sonoma Coast, CA) with the refrigerator off. Got there and the refrigerator would not start - could not get the green light to stay on. Repeated level fine tuning was futile. After that trip we had a backyard session trying to get it lit and after several leveling adjustments it stayed on and cooled down. "OK", we thought, "Leveling is really important - good to know". It even did repeated successful test starts before our next trip. The night before the trip it's no go - will not start. At camp it didn't start no matter how much leveling was done. We did a couple of more trips without a working refrigerator (no shore power at most California state campgrounds).

Over the summer we spent a lot of time on the forum as we set up our solar charging system, moved the spare tire to the tongue, did the PWM fan mod, made up a set of awnings and acquired all the security gadgets. All the while reading every thread regarding this refrigerator problem and trying every technique and incantation that worked for others (slowly opening tank valve, turning on burners for a minute, etc.) Read with trepidation Michigan_Mike's refrigerator removal to get at the thermocouple. Downloaded the 3163 service manual, the troubleshooting charts seemed daunting.  Read and reread the 2016 thread started by Nomad: https://tab-rv.vanillacommunity.com/discussion/3860/fridge-wont-light-for-nothin/p1 several times.

We even called around to local RV dealers and found they either only serviced/repaired units they sold or had weeks long waits to get it in for diagnosis. Finally, after completing the other T@B projects, I had to directly address the refrigerator problem. I focused on putting all the hints, comments and fixes in Nomad's thread alongside the troubleshooting chart on page 16 of the service manual https://tab-rv.vanillacommunity.com/discussion/6390/norcold-service-manual#latest and had an ---

Epiphany About Easy Diagnosis

There are 4 parts that can cause this problem: relighter ($160), thermocouple ($25-$30), interrupter ($25), safety valve ($40 - $100) - see diagram page 17 in service manual.

I really paid close attention to the last 12 boxes on the "Burner Ignites But Flame Will Not Hold" flowchart on page 16 and had one of those head-slapping Eureka moments --- the heart of the diagnosis of this type of problem are the two terminals on the interrupter. All you need to determine which part is bad is a short jumper wire with alligator clips on each end and a multimeter that will measure millivolts at those two terminals. Figure 10 on page 15 of the service manual shows where to test those terminals.

Here is the interrupter and the two white wires attached to the terminals:

After all these months of dreading the prospect of having to pull the refrigerator out to get at the burner box and thermocouple, I was actually anxious to lift up the burners and do the tests to quickly identify which part was faulty. I had my jumper wire and multimeter ready to go.

I used an Xacto-type knife to cleanly cut through the silicone seal of the stovetop, took the little caps off the screwheads, and used a small star-bit screwdriver to turn the screws 1/4 turn counter-clockwise and lifted up the burners. Instead of rotating it around to sit on the sink I just carefully positioned a 2x4 to hold up the burners. (The propane and electrical wires remain attached to the burners.) In the picture below you can see the clips that secure the burners and why only a 1/4 turn is necessary.

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So, if you are having this problem don't be intimidated by page 16. If your stovetop burners appear to have a normal flame, skip on down to the box that says "Is the tip of the thermocouple in flame and clean of carbon?"  Since we would have to pull the refrigerator out to find that out - let's assume it is OK. Proceed to "Is the thermocouple connection at the interrupter tight?" Whoaaa --- mine was significantly loose - finger-tightened it about 1/2 turn and snugged it 1/8th or so more with a wrench. PROBLEM SOLVED - green light stayed on first try. After it worked I backed the nut all the way out and used blue Loctite to secure it. This loose nut has been the culprit for others in the forum, but I really didn't think I was going to be so lucky.

If you are not that lucky then carefully step through the flowchart using figures 9 and 10 to check the wiring connections, connect the interrupter terminals with alligator clips on a wire, if still no flame reconnect white wires and then run the voltage check on each interrupter terminal. Then use the voltages and the last two rows of the page 16 troubleshooting chart to determine which part is bad. For most of us it just takes a few minutes to either fix the problem (loose nuts or wires) or determine which part is faulty. (Full-timers or people with months of continuous use, do face burnt thermocouples and corroded spark electrodes that require pulling out the refrigerator to get at the burner box.)

By making a clean 45° cut in the silicone at the edge of the stovetop it goes back in tightly - don't think it needs to be cleaned up and resealed (yet).

Even if you choose to take it to a dealer for repair (say, for a thermocouple replacement where the refrigerator has to be pulled out) it only takes a few minutes to figure out which parts are OK. You will then be equipped to deal with any sort of unscrupulous flimflammery when someone at the shop says, "Well -- sometimes a bad thermocouple can cause an electrical cascade and it burns out the interrupter and the relighter, but we'll let you know." Hopefully there are other service options. It probably won't be particularly relevant if you're at the only service center within a hundred miles, but the "Norcold Limited Warranty Time Allowance Chart" on page 7 is quite informative.

One other interesting tidbit from page 19 - "Diagnosing Cooling Problems" of the service manual states that a marginal off-level infraction allows continued cooling at a reduced level of cooling. The operating limits are 3° front-to-back and 6° side-to-side. Operating outside those limits for an extended period of time can result in irreparable damage. One other very important thing from that page is that if you smell ammonia or see yellow powder around the refrigerator you have a refrigerant leak and the cooling unit must be replaced.

In retrospect it is easy to see how vibration and thermal cycles could loosen a threaded connection that is not supposed to be overtightened and cause the erratic, temperamental and gradually worsening behavior of the refrigerator using propane. 

(BTW: thermocouples are pretty interesting: https://www.brighthubengineering.com/hvac/27680-what-is-a-thermocouple/
and https://www.brighthubengineering.com/manufacturing-technology/53682-what-is-a-thermocouple-how-thermocouple-works/  )

One final point: Nomad's 2016 9 page "Fridge Won't Light for Nothin :-(" thread has all the puzzle pieces on the table. It mentions loose nuts, using volt meters, using the troubleshooting flow charts, which parts worked for several people and much more. Though I read it several times over the last few weeks, I just didn't see the big picture or understand the nuggets sprinkled throughout the 9 pages. The service manual charts were also a bit intimidating at first.  Along with stories of costly misdiagnosis by techs, the thread does contain a great deal of useful information, photos and part numbers - it was the key for me and I really appreciate the insights scattered around in that thread. I've tried to boil it and a few other helpful, relevant threads down to one (rather long) post that gives some direction to anyone who encounters this problem and "pay it forward" for all the tips, ideas and help available in this community. 

Ohh - one other final point: if you are totally new to RVs/trailers like we were, are overwhelmed by all the fun projects and are pushing attention to any Norcold 3-way problem to the bottom of the list, don't wait any longer. The service manual for the Norcold 3163 (and other models) has detailed troubleshooting flowcharts and wiring diagrams to diagnose common electronic control system problems for all modes using only a volt meter and taking measurements at points that are readily accessible at the top of the refrigerator. 

If you do go poking around in the refrigerator innards please read and follow all the safety precautions - both electricity and gas are lurking - there is risk. If you are a rank novice and don't understand the value of insulated-handled screwdrivers and pliers, have never experienced the thrill of accidentally letting your screwdriver or pliers tip contact an adjacent wire or terminal or have never appreciated and marveled at how big a spark 12 volts can provide you probably should bite the bullet and seek professional help. ;>)

Joe

jgram2

@rajamar So tightening those interrupter nuts solved your fridge problem? That is good news. Thank goodness you had the patience to wade through the forum information in conjunction with the troubleshooting details in the Norcold manual. That’s even better news for the rest of us. Many thanks for your efforts.

rajamar

jgram2 said:

@rajamar So tightening those interrupter nuts solved your fridge problem? That is good news. Thank goodness you had the patience to wade through the forum information in conjunction with the troubleshooting details in the Norcold manual. That’s even better news for the rest of us. Many thanks for your efforts.

Yes, tightening that one little nut that attaches the thermocouple to the interrupter did the trick for us! 

Sharon_is_SAM

@rajamar, thank you for this awesome compilation!  It is going in my list of posts for members who have problems lighting the frig!  

ericnliz

@rajamar, Duly noted & bookmarked for future reference! When I did my inspection of the fridge hoses ( for the recall about a year & a half ago) I also took the stove top off to inspect the hoses. While I had the stove top off, I inspected & tightened all the fittings, both propane & electrical while I was there. I must have had the beginnings of the same symptoms as did you. I always had to try lighting two, or three times before the fridge would stay lit. After tightening, once, twice at the most. Thanks for sharing your in-depth solution. You have no idea how many folks I've spoken with that have had similar issues. Please note you've helped more than you know, and I , for one appreciate every time someone posts a solution to a problem to help out others.   

rajamar

ericnliz said:

@rajamar, Duly noted & bookmarked for future reference! ... Please note you've helped more than you know, and I , for one appreciate every time someone posts a solution to a problem to help out others.   

Thanks. This is such a friendly and helpful forum, with all the tips, mods and problem solutions. It has helped us greatly. I was basically trying to write the post that I had been hoping to find many weeks ago. Hopefully, it will save others some time and frustration over this issue.

ericnliz

@rajamar, 'Ya done good!

Michigan_Mike

Good stuff, very helpful and will no doubt save some other frustrated and disgruntled owners a trip to the repair shop down the road.  Thank you for the great write-up and the links within it!  Well done!   

dragonsdofly

@rajamar, X 10!

dougm

I just read your very well written thread about how you (@rajmar) solved your refrigerator problem. It sounds exactly like what I am experiencing with my 2017 T@B 320S with a Norcold N180 3R.  I've had it for just over a year now (figures that the warranty just ran out last month) and this past weekend on the second day of a boondocking trip, the fridge died even though there was plenty of gas.  When I looked through the pilot flame viewing port that is accessible be removing the lower vent to the right of the T@B's entry door, I can see that the burner lights when the lighting button pushed in.  The temp indicator goes into the green but as soon as I release the lighting button, the temp indicator drops and I can visually confirm via the viewing port that the flame goes out.  Given the relative youth of my rig (maybe 15 outings total), it is hard to imagine how the thermocouple or any other mechanical parts could have failed so soon.  However, a high resistance connection between the interrupter and the thremocouple leads caused by vibration or whatever (as you found was causing your problem) could explain why the temp indicator could be working but not enough current is flowing from the thermocuple to the keep the safety valve open. 

Assuming, that my problem is the same as your and all that I need to do is tighten up the screws connecting the thermocouple leads to the interrupter, I would like to confirm that what you did to access the interrupter was to slice the silicone seal under the two burner stove, turn the stove hold-down screws 1/4 turn counter clockwise, and then lift up the stove and use a 2X4 to hold it up so you could get to the interrupter.  Is there any other advice you or others could offer to me?

Thanks again for taking the time to write your post for folks like me to find and refer to.

rajamar

dougm said:
...

Assuming, that my problem is the same as your and all that I need to do is tighten up the screws connecting the thermocouple leads to the interrupter, I would like to confirm that what you did to access the interrupter was to slice the silicone seal under the two burner stove, turn the stove hold-down screws 1/4 turn counter clockwise, and then lift up the stove and use a 2X4 to hold it up so you could get to the interrupter.  Is there any other advice you or others could offer to me?

Thanks again for taking the time to write your post for folks like me to find and refer to.

You got it.

Except not screws - I just had to tighten (and use blue Loctite) on the brass nut connecting the copper thermocouple tube to the interrupter. It's just to the left of the arrowhead in the first photo. 

It was quite a satisfying fix after weeks of research and visions of having to pull and reinstall the Norcold. 

Good luck.

dougm

Thank you so much. I consider myself very lucky to have found your post so quickly. I’ll let you know if it actually fixes my problem. I am assuming that though our fridge model #s are different, the fact that they both fit in the same trailer means that the access and layout are the same or similar.  I will find out soon enough!

rajamar

Glad to help short circuit the frustration cycle - hopefully.

Looked at a Norcold N180 user manual and it doesn't mention or show diagram callouts for the thermocouple and interrupter like the 3163 service manual. Things are a little different but I would check the tightness of the nut connecting what obviously is the thermocouple (To Burner in N180 wiring diagram).

3163:

N180:


Also attached is the N180 3X User Manual .pdf I found online.

BTW - Don't forget to take a couple of pictures of the top guts of the N180.

dougm

Thanks @rajamar for researching the difference between the N180 and 3163.  I tried to use google images to see the difference but it wasn't easy to tell.  I will take pictures and post them when I do the work this weekend.  It would be nice to have access to a real manual with proper documentation rather than the skimpy owners manual we are given.  Do you or anyone know how to get the actual service manuals?  

jkjenn

Let me just add my issue and solution to this thread, for posterity. My fridge would appear to light, because the green light (3163) would come on, but I was bit hearing the tell-tale, "whoosh" and the grudge was not cooling. It turned out to be a corroded ig iter, which could only be accessed by removing. nuCamp discovered and fixed the issue for me after taking to the dealer, who told me the fridge had to be replaced.

rajamar

dougm said:

Thanks @rajamar for researching the difference between the N180 and 3163.  I tried to use google images to see the difference but it wasn't easy to tell.  I will take pictures and post them when I do the work this weekend.  It would be nice to have access to a real manual with proper documentation rather than the skimpy owners manual we are given.  Do you or anyone know how to get the actual service manuals?  

Service manuals are indeed hard to find for some things. I did come across an N180 parts list at thetford.com and a Norcold 323 Service manual which appears to be an older version of the small RV 3 way fridges. I certainly hope you just have a loose nut  , but if not reread the paragraph in my post that starts with "If you are not that lucky...". I think with my thumbnail troubleshooting paragraph, the flowcharts in the 3163 and 323 service manuals, the N180 parts list and a multimeter you should be able to pinpoint the problem.

dougm

Thanks for all of the helpful suggestions @rajamar.  Today, I removed my gas stove from the counter top to gain access to my N180 and discovered that the thermocouple wiring layout and connections were very different from what you saw with your N3163.  There is an un-anchored loop of thermocouple lead (on the far right in the photo below) that is spliced to two wires leading to the mode switch and safety valve and another copper coax line going to the gas safety valve (very different from @rajmar's photo ).  Just to be safe I checked and tightened the coax thermocouple connections that may have been a bit loose but I was also very suspicious of the splices and the fact that the assembly could bounce around quite a bit with expected trailer motion.  Not a very reliable wiring set-up in my view.  I will probably install some adhesive mount wire restraints.



That all said, I discovered in the end I discovered that that my problem could have been caused by my own error as I noticed that the fridge mode switch was in the off position and when I turned it to the gas flame position, I was able to start the flame and my fridge worked fine.  The possible selections of the mode switch are: 12V DC, AC line, gas flame and off as shown below. 



I'm not sure when and how the mode switch got set to the off position (fully CW) but in this position, the flame can be lit with the igniter but the thremocouple is disconnected from the safety switch and when the lighting button (far right)  is released, the gas flame goes out.  

I believe that what may have happened was that I had pre-cooled my fridge overnight using AC line power before I left for my trip.  When I arrived at my campsite, I was able to successfully light my fridge pilot so I must have had the mode switch in the gas flame position.  Later in my trip, I (or someone else) may have mistakenly switched the mode switch to the off position.  When I noticed that the fridge wasn't working, I may not have checked the mode switch.  I honestly can't remember.

An alternate explanation is that the mode switch was set correctly but the thermocouple connection is intermittent.  I will just have to wait and see if the problem recurs but for now, my fridge is working just fine.  Thanks for all the help and I'd appreciate and will respond to any further questions or comments.  Cheers!

rajamar

Yes, that big thermocouple loop is odd.

Whenever I get stuck in repeated faults in any process I try to clear frustration from my mind, open the manual and step through the instructions. It forces you to examine the state of all relevant switches and knobs. 

My 20+ years in IT network and desktop support taught me that a surprising number of "my computer|monitor|keyboard|mouse|printer isn't working" calls were solved when I asked, "Is it plugged in?" and/or, "Is it turned on?" Sorry I forgot to apply that lesson here.

dougm

Yes, I too have worked with electronics and trouble shooting for my entire career but its so easy to get caught by one of these kinds of human error induced problems.  I've also found that going over the situation with someone else can help spot problems like a switch being in the wrong position.  I will remember that lesson the next time I have a problem like this while camping.

In your original post you mentioned moving the spare tire to the tongue and a PWM fan upgrade.  I'd be interested in learning why and how you did both of these if you would be willing to share what you have learned.  I haven't heard about the fan upgrade but I have thought that moving the spare with be helpful to increase the tongue weight and give better access to the spare.

rajamar

dougm said:

...

In your original post you mentioned moving the spare tire to the tongue and a PWM fan upgrade.  I'd be interested in learning why and how you did both of these if you would be willing to share what you have learned.  I haven't heard about the fan upgrade but I have thought that moving the spare with be helpful to increase the tongue weight and give better access to the spare.

This is such a collaborative community. All projects I've done were only possible because other forum members found something interesting on the web, or here in the forum, did the project and shared their tips and problems. Then there is this spiral where others do it, improve it and share any different mistakes.  

Spare tire to front - done primarily because there is a real clearance problem with the stock rear position of the spare when going in or out of a steep home driveway or through a street gutter in or out of a sloping gas station driveway. Also, it is a bit of a chore removing the spare from stock position. You don't want to be forced to do it on a dark rainy night. There are several threads on this topic. This is the one I followed and did:
https://tab-rv.vanillacommunity.com/discussion/comment/104335#Comment_104335

There are a couple of techniques to removing the spare in several threads. But here is my contribution:
https://tab-rv.vanillacommunity.com/discussion/comment/104512#Comment_104512

The PWM fan control mod is done because the stock 3 speed controller is a fairly large drain on the battery due to the fact that the stock controller uses wire coil resistors to reduce the lower two speeds. Thus the slowest speed is fairly fast (I assume to keep the copper wire coil resistor from melting), noisy and doesn't reduce the drain on the battery that much. On the other hand, the PulseWaveModulation controller, by literally rapidly turning the power off and on at continuously variable frequencies allows the fan to slow down to about 1 or 2 rotations per second for whisper quiet ventilation with substantially less battery consumption. This is the thread that I used and contributed to:
https://tab-rv.vanillacommunity.com/discussion/7200/variable-speed-pwm-ceiling-fan-mod-10-bucks/p1

One tip regarding the longish project threads - make sure to read the entire thread through a time or two. Many times somebody comes up with an idea or component, but later on someone else points out a better one.

One other sort of housekeeping tip to keep things orderly - the moderators would probably prefer that the questions in the paragraph I quoted above be broken out into a seperate topic like:

Subject: Where to find PWM controller and spare tire remount info

"@rajamar - you mentioned in your Norcold 3163 3-way refrigerator fix thread that you moved the spare tire... etc."

dougm

Thanks @rajamar for all of the helpful information you have provided.  I will review and let you know if I have questions.

ColoradoJon

Found this thread while researching my Norcold 3-way fridge problem on my 2017 320S - burner lights but goes out when you let go of the button.  For those keeping track, my problem was NOT a loose thermocouple!  I was disappointed to find that all parts, bolts, and nuts were nice and snug.  However, disconnecting the two white wires and testing with the jumper wire resulted in a fridge that would light and stay lit.

According to the Norcold user manual troubleshooting section this means that the relighter needed replaced.  I ordered one from Amazon for $106 and installed it myself.  It was a bit tricky as the relighter is not easily accessed through the stove opening, but it is doable.  I had to use a stubby phillips #2 to remove the two wood screws.  The one on the far right side was tricky and I had to be very careful not to drop the screwdriver or the screw.

It's just a matter of removing two screws and then reconnecting the six blade connector wires and one ground wire.  Fridge works perfectly now!

Oh... my stove did not have the quarter turn counter top locks.  It has wood screws the screw into wood corner braces.

Michigan_Mike

It’s always nice to read a happy ending to a problem!  Thanks for posting your results up and am glad you got a good bang for your bucks and that things worked out!  👍🏻

Anna

I have the same issue with my Norcold.  I have a T@B 2004 - one of the originals.  I am not confident enough to do this on my own.  I am sure the dealer would charge me about $300. to do what you did.  How long did it take you to change out the part?  

GatorEgg

So now my turn.  After being intermittent for more than a year my N180 3way  won’t light.  I figured easy fix for this career electronics tech.  Lifted out stovetop.  No 1/4 turn fasteners or sealant just screws into countertop.  No important components visible, all must be on the side. Switches correct, check.  Connections secure, check.  Power metered where I can reach, check.  I pulled trailer exterior side grills.  Nothing really accessible from there.  So it appears fridge has to come out of counter.  I’m thinking it’s a dealer visit time.
I may just do it.  They can always fix it if I screw up.

Grumpy_G

Sorry no electronics here ! I don't know if the service manual is on here somewhere but Google can find one for you. Here is what you should see on the top of the fridge. 


On the side there are just the AC and DC heaters, the burner and the thermocouple. 

druthazer

OOPS REMOVED and CLEANED Orifice with alcohol and it WORKS....

My 2017 Tab 320 S (with Side vents) 3Way Norcold  Fridge does not light on Gas at all.   
All knobs are good and stove lights so there is propane.
Followed all lighting instructions...no joy.
I opened side vent to access the igniter area and tried using a Stick lighter with flame right in igniter box while holding the GAS knob in.  no joy.
Appears that gas is not getting to the igniter.  What might be stopping that?

Opened stovetop.  both fuzes look good and all connections are tight
The fridge indicator for battery comes on when dial is set to battery...
OOPS   REMOVED and CLEANED Orifice with alcohol and it WORKS....

THANKS

AldebaranJill

@rajamar

Thank you for this wonderful write up. I am currently camping so cannot root cause until I get home but wanted to ask your opinion on my fridge’s behavior.

From day one, back in 2013, the fridge has been difficult to light on propane, which is how I mostly run fridge. Over time learned all the tricks and incantations. As years went by it got more and more finicky. I had to hold the red button in for a full minute last trip. Once it is lit, and green light is on, it always remains lit.

This trip I arrived at site, leveled, opened gas slowly, ran both burners and it refused to remain lit. For four hours, I kept trying, waiting 15 min intervals. Got up to 1 min 30 sec of holding red button. Nope. Finally went to sleep, figuring I would take to dealer. Woke up and tried again. Nope.

A better campsite opened up and I moved trailer, maybe a 1 minute drive down paved road. Pulled in, leveled, turned on propane. Did not light burners. And in one last illogical try, thinking maybe the fridge would like this view better and reward me by staying lit…. it stayed lit on FIRST try. It is now happily cooling down.

Given your four parts that can cause trouble:

“ There are 4 parts that can cause this problem: relighter ($160), thermocouple ($25-$30), interrupter ($25), safety valve ($40 - $100) - see diagram page 17 in service manual.”

and given my fridge’s history and behavior, would you suspect a loose connection (like yours had) or a defective component? I am curious if a defective component can cause intermittent issues or if the nature of this, seemingly a short drive, suggests a loose nut. Or maybe I am the loose nut and this is all a dream and I am still asleep. 

Thank you again!
Jill
2013 T@B Maxx

rajamar

Ohhhh..... I know what you're going through. Checking tightness of the thermocouple nut should definitely be the first thing to check after lifting up the stove. As you have probably seen from reading relevant threads here it has been the culprit in several, but not all, of the stubborn lighting cases.
Good luck.