Tech Tip: Auto-Relighter for Propane Refrigerators

pvstoy

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Tech Tip: Auto-Relighter for Propane Refrigerators

I have been thinking of writing up a post on this subject for a long time now. Thanks to Russell Jones asking me about it, I’ve gotten off my duff. So here we go…

I have installed this unit in the three refrigerator units that FWC have installed since 2001: Dometic, and NorCold with and without freezer models. Below will be a write up and pictures for all three models.

The unit is an Atwood Pilot Relighter Kit for Water Heater, #MPD 93212 sold on a 5” x 11” blister pack card; it costs around $65.00 without 9-volt battery.

What is it?
It is a thermo coupler that, when cool, will use the juice from the 9-volt battery and repeat a spark over and over to a ground nearby until the probe heats up. Just like a spark plug.

Why would I want one?
They are not needed by everyone but can save your food or keep your beer cold while running on propane. The refrigerator flame is shrouded pretty well, but in a wind event the wind could blow out the flame. Once the flame is out, your gas valve thermo coupler will cool off and close the gas valve. Installing the relighter just gives some added insurance that the refrigerator will continue operating if the flame blows out.

I have been running just the propane and not on battery while driving. It is important that the refrigerator be fairly level, both front-to-back and side-to-side, when you park your vehicle; front-to-back is more critical. Damage can be done to the refrigerator unit if you are too far off bubble.

I first learned about this from one of my many phone conversations with Mike Duncan. Mike was a salesperson for Ben Burnett at FWC. Mike gave me a general idea as to what to do, but installation was by trail and error.

First set up was on my Ranger FWC with the Dometic refrigerator.
For this I removed the Pizzo push button lighter. I placed the probe in the grooved clamp where the Pizzo starter was. You might have to bend the metal electrode bracket that attaches to the probe for a good fit. As you can see in the pictures, there was a lot of shaping of the tip. This was my first one so there was the trial and error part. Just get the tip in the flame without it being in the way. Make sure the tip is close enough to a ground to produce a good healthy spark toward the flame area. This is where the propane is.

Second set up was on a 2004 Eagle FWC with the Nor-Cold refrigerator.
On this one I also removed the Pizzo push button lighter. Somehow I was able to detach the metal electrode bracket and flip it around and reattach it using a screw to tighten the probe back to the bracket (if memory serves me?). In the picture you can see that I bent the bracket and attached it to the top of the metal frame. I was able to slide the probe forward and position the probe on the edge of the flame. It should have been more into the flame because at altitude the flame has a much smaller diameter. The spark here jumps to the burner tube.

The third setup was on a 2007 Kestrel FWC with the Nor-Cold refrigerator freezer combo.

On this unit they put the burner way in the back corner with a good wind shroud around it. This may not need a relighter, but if you were backpacking for a few days, this will give you some added insurance.

I left everything alone on this one (I left the Pizzo starter in place). You light and adjust the temperature settings, along with the source switching, inside the camper. So really you don’t do anything on the outside. I found a good spot to mount the electrode bracket. I bent up the bracket and mounted it on the back wall of the shroud. Like the last ones, put the probe into the flame and cause the spark to jump toward the propane.


These were just three examples of how I installed the Atwood Relighter Kit. Be creative, there is always other ways to mount, screw, bolt and bend to achieve the same results.

***** For this application, the relighter is being used differently than its intended use. Use sound judgment if you use this information to modify your unit. Know what you are doing and how things interact. If you don’t have the aptitude for doing this kind of work, then please seek professional help to assist you with this modification. These refrigerator units are not cheap so please don’t cause damage.*****


How would I use them?

On the FWC Ranger and Eagle, I will purge the air in the propane pipe to the burner. You light it just like you did with the Pizzo push button but now just slide the switch to on. You will hear the spark and if the propane is there it will light. To turn it off just turn the source selector off or to another source and when the flame goes out you will hear the spark. Slide the unit switch to “OFF”.

For the Nor-Cold refrigerator freezer combo, light just as you would from the inside of the camper using the Pizzo push button. While on propane, go outside and turn on the Atwood unit and turn it off when done using propane. I guess you could light it with the Atwood unit if the Pizzo fails.

Pictures for first set up was on my Ranger FWC with the Dometic refrigerator
 

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Pictures for second set up was on a 2004 Eagle FWC with the Nor-Cold refrigerator.
 

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Pictures for the third setup was on a 2007 Kestrel FWC with the Nor-Cold refrigerator freezer combo.
 

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Pat,
This looks very interesting. Thanks for the detail. Excellent job. My questions are these.

1. Do you actually use the refer on propane all the while you are driving?

2. Does this unit insure it stays lit while driving in up and down terrain?

3. Does the refer stay as cold while driving as when you are stationary?

Thanks again for the info.
 
Thanks Jay

Hi Jay,

Pat,
This looks very interesting. Thanks for the detail. Excellent job. My questions are these.

1. Do you actually use the refer on propane all the while you are driving?

Last year on my outings I have been only on propane. With all the stop and go while working out of the camper for photography, it is too much trouble to keep switching back and forth. If it is cold outside and would require the flame to be on the lowest setting I think it would still keep it lit. If it is that cold I drive with the refrigerator off because with the battery on will freeze the contents. I would like to hear of other people just running on propane.

2. Does this unit insure it stays lit while driving in up and down terrain?


The unit will keep the flame going. When traveling I keep the flame up on the high or medium setting. This makes the flame better to stand up to the wind blowing it out. I have been in the wind camping and have heard the spark kick on every so often. Just one spark and it was back on. I try to keep that corner away from the direct wind.

3. Does the refer stay as cold while driving as when you are stationary?

Thanks again for the info.

I have not noticed any difference. I'll try this year to pay more attention. The truck is constantly moving so that keeps the rise and fall of the stuff in the tube always moving and won’t freeze up.
 
I run my reefer on propane only.I usually take a 2 week trip at the end of September and have run mine for 2 weeks straight the last 3 years in a row.I also have learned to turn the pilot down on cold nights or risk freezing the contents.Making ice overnight on purpose is some times an option.These units will not work very well here in the Az. desert during the summer but most people (me included) head for the mountains then anyways.The most amazing thing is the minimal amount of propane it takes to run them.I also carry a Coleman Extreme ice chest and between the two I am able to manage my cold storage very nicely.
I know how much you guys like pictures so here is one crossing the Salmon River 10/06
 

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One Of The Best

Patrick, this post is one of the best i've seen so far, I think it's something I can use, thanks. I have just finished up some serious mods on my camper, took lots of pics, but in the wrong format, and i'm having trouble shrinking them down. I'll keep trying. I CAN SMELL MY HALIBUT, IT'S IN THE OVEN UM.........TASTY
 
Thanks for the feed back.

Here is a bridge picture crossing the Green River with the old FWC Fleet. A wood plank suspension bridge weight limit 3 Ton. That was a noisy bridge. And one for The Fisherman. Lahonton Cutthroat Trout at Pyramid Lake.
 

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Pyramid

Nice one, I used to hit that place once in a while, in fact I took the worst fresh water a#% kicking i've ever had in that place, the wind can really blow up there. These days it's Eagle Lake, Strawberry Res. and Henerys Lake in Id. Got a real nice Lund Alaskan for that job, maybe we can hook up at some spot like these places. I've learned a few new tricks lately. KEEP CATCHING
 
Pat,
I agree with Salty This looks like an item I could use. I do think I'll try propane only on my next short trip just to see if it will keep running while on the road through the mountains. Thanks for the info.

Pat & Grass Cutter,
Nice pix. I love bridges that scare my wife. I think she would opt to walk accross both. She not good with heights. She actually walked up the road to Mokee Dugweep.
 
Attempting to run my refrigerator on propane all the time, I find the flame blows out when driving over 45. People are requested to post how they resolved that problem. The electronic spark above is part of the solution.
 
I'm guessing the fridge model might have something to do with it as well... I have run mine completely on propane the few trips we've used it on and it has yet to blow out. (knocks on wood) The trips have included everything from interstate travel at 70 to 80 mph and all day offroad stints from bouncing washout areas to high speed washboard.

I like this idea though.. it gives some piece of mind. I would hate to go back to the camper while setting up camp to find warm beer!
 
Great Mod

Patrick,

Thanks for the great mod!

My parts are on the way and I intend to install this weekend.

SB
 
12V vs Propane

We generally run on 12V on long hauls and switch to propane if we will be doing much stopping. 12V seems to provide more even temperature, but on really hot days, we run on propane, since it can cool a bit better than 12V.

I added a 12V computer fan in front of the coils to improve cooling and it is noisy enough, fortunately, that it reminds me that we are running on 12V when we stop, so I don't forget to switch to propane. In the past, I ran down the battery more than once. (But just in case, I also installed a BatteryBrain to protect the FWC battery.)

I strongly recommend a $25 external fridge thermometer. To keep the fridge between 34F and 44F' requires constant adjustment when running on propane. With propane, the fridge is VERY sensitive to the outside temperature and humidity. If you mount the thermometer readout above and on the right of the fridge door, you can read it through the side window.
 
20 Minute Simplified Dometic Install

EDIT: I found the Dometic electrode fails after a number of uses. Install the Atwood electrode.

From the outside, this looks like a potentially hard and possibly unsafe mod. It's not. I did it in 2 hours, but now you can do this in 20 minutes! What's more, you aren't going to fiddle with the fuel delivery system, so the mod becomes far less risky.

First, hat tip to Patrick for the initial post and great idea. I cannot describe how much I despised starting my refer. With the auto re-lighter, it's as simply as turn the knob, flip the switch, and push and hold until clicking stops!

Parts:
  • Atwood Pilot Relighter Kit for Water Heater, #MPD 93212 (per original post)
  • 9 volt battery
Tools:
  • Pliers
  • Phillips Screwdriver
  • 5/16" or 8mm wrench or ratchet (may differ for you)
  • Optional: Small standard screwdriver, pocketknife, thin kitchen knife, etc.
Instructions:
  • Get tools and parts.
  • Discard Atwood electrode and wire. We aren't using them.
  • Ensure propane is OFF.
  • Ensure power to refer is disconnected!
  • Carefully remove the wire from the bottom of the push button lighter (this is the hard part). Be careful here, you don't want to short the wire.
  • Position--DO NOT install!--re-lighter body such that the middle screw can be used for ground and the battery is easily accessed(see pic 3).
  • Attach ground.
  • Using pliers, squish the end of the push button connector flat (see pic 1&2).
  • Attach modified original electrode wire to Atwood re-lighter. (If you squeezed to much, use your optional tool to undo it a bit!)
  • Insert battery.
  • Install (i.e. screw the Atwood unit down) after testing.
Test:
  • Turn re-lighter on. You should hear clicking and see, if it's dark, a spark through the "peep hole".
  • Apply propane, everything should now "just work".
That's it. Easy huh?
 

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So will this thing work on a Norcold too?

And while we're talking propane....I was telling a friend that I fire up the fridge before I leave home and run it on propane full time while driving. He thinks that that is a dangerous practice because of fire danger if there's a collision or other mishap.

Any of you have thoughts on this?
 
Hi Scott......

Thanks for taking it one step further.

I did not think about using the existing probe as a thermocupler. As lond as it is in the flame and the striker will not spark, and when it cools it will spark then it is a go.

Hi chnlisle,

If your probe will work as above then go for it. The bigger freg with the freezer I would leave alone and just add the Attwood unit seperatly.

Doom and Gloom....What ifs are pleanty up the wazoo. A lot of the coachs and trailer units auto switch from AC to LP when AC is offline. Most don't run on battery (DC). The only problem you could have is in a closed place or if the flame gets a ton of vapor from filling up with gasoline. How many houses blow up with a hotwater heater in the garage and vapors.

There are a lot of "it could happen" but I would not worry about running on LP, I've been doing it for years as with many others.
 
it should work on the Norcold refrigerators too

(I think Patrick added one for his friends that are using a Norcold in their FWC)

I will let you know in a few weeks, I also ordered one today for my camper. I have the smaller 1.7 cu.ft. Norcold refrigerator.

Patrick showed me that years ago and now I'm finally getting around to actually trying it out (laughs)

Thanks Patrick & Scott for the helpful write ups !


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So will this thing work on a Norcold too?






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