Tech Tip: Auto-Relighter for Propane Refrigerators

[RJones]

Auto Lighter

Thanks for this mod Patrick. It's great to come back from a days hike and still find your refrig cold. Or wake up in the morning after a breezy night in the desert and all is still cold.

Great Mod!

 

[ScottBailey]

Yeah, Probably

So will this thing work on a Norcold too?
Chnlisle,

Probably.

I'm supposing the push button part is pretty much the same from one unit to the next (i.e. Norcold, Dometic, misc BBQ grills, etc.).

The potential issue is wire length. So, maybe you'd need to extend the wire a bit. It's worth a try. Looks like Stan will let us know soon...!

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?
This is a risk. One that LOTS of RVers take everyday. I haven't read about any disasters, but I haven't looked.

Put your unit in a big, American truck, and you should be OK.

Thanks Patrick & Scott for the helpful write ups !

Stan,

It was my pleasure.

For the larger Norcold, you could probably put the Atwood re-lighter inside the camper... I'll let someone else figure this out and post it.

An even better fix would be to split the factory lead and keep both the Atwood and push button, but I think you'd need a diode to ensure the push button didn't kill the Atwood... Don't know if this would work. Again, I'll leave this for someone else.

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.

Patrick,

It took me awhile to get there myself. Ultimately, I'm probably just lazier than you are. I'm slow going mechanically, and it would have taken me another 2 hours to figure out how to mod/mount the Atwood electrode!

Anyway, to add to your comment: you can hear the re-lighter clicking when it sparks. So it's easy to test an install does what it should without disassembling the unit.

 

[chnlisle]

Thanks Pat I felt the same as you but it never hurts to get a 2nd opinion.

Stan I have the same size Norcold so take pix of your install.

Scott my guess is a Ram diesel with no gas fumes wont be a problem.

 

[camelracer]

I've been thinking of doing this mod to initially get the frig started. Sometimes it fires right off and at other times it takes forever pushing the igniter button no matter how long I purge the propane. With the Norcold controls inside the camper, using a lighter to manually start it is a 2 man operation.

What I'm wondering is how the Atwood unit knows when the flame goes out. It looks like the igniter wire has a single conductor so it can't be a thermocouple and it has to react faster than the gas valve interlock. Inquiring minds need to know.

 

[ScottBailey]

Yep

I've been thinking of doing this mod to initially get the frig started. Sometimes it fires right off and at other times it takes forever pushing the igniter button no matter how long I purge the propane. With the Norcold controls inside the camper, using a lighter to manually start it is a 2 man operation.

What I'm wondering is how the Atwood unit knows when the flame goes out. It looks like the igniter wire has a single conductor so it can't be a thermocouple and it has to react faster than the gas valve interlock. Inquiring minds need to know.

I initial decided on this mod to simplify the starting process; however, ensuring the refer stays lit while traveling--the one time I tried traveling with refer on propane before the relighter it blew out--further justifies the update.

I don't know how it works, but I know it does AND I've recently field tested it and am thoroughly satisfied with the update. I'll see if I can find an EE where I work also knows about RVs...

The proof is in this delicious breakfast at Roosevelt Lake:

 

[chnlisle]

Stan where are the pix and discription of the igniter mod on the Norcold.

 

[Kokopelli]

Norcold auto relighter

Has anyone done Scott's 20 minute mod on a norcold? Just got my Eagle last week and went to do it, but the setup is different than Scott's. Looks very difficult to get the push botton wire off due to access. Any suggestions would be appreciated!

 

[Jack]

Pat,
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.
\
For some of us, the phrase is "the more firma, the less terra".

 

[pods8]

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.


Scott, I just got my relighter and tried it this route first before going full blown if it was unneeded. However on my domestic fridge the stock sparker does not sense the heat and thus the relighter just keeps clicking once the flame is going (I double checked this by turning off the relighter and letting the flame run for a minute and then when I turned it on it just started clicking away even though there had been a flame for a minute already).

I'll work on pvstoy's method when I get a few more minutes.

 

[ScottBailey]

Scott, I just got my relighter and tried it this route first before going full blown if it was unneeded. However on my domestic fridge the stock sparker does not sense the heat and thus the relighter just keeps clicking once the flame is going (I double checked this by turning off the relighter and letting the flame run for a minute and then when I turned it on it just started clicking away even though there had been a flame for a minute already).

I'll work on pvstoy's method when I get a few more minutes.

That sucks. Clearly this isn't so simple?! I usually have a few seconds of clicking -- maybe 5? -- while it warms up. Longer on low or medium, but I think my valve needs adjusting as high is the only setting for a reasonable temp.

 

[pods8]

That sucks. Clearly this isn't so simple?! I usually have a few seconds of clicking -- maybe 5? -- while it warms up. Longer on low or medium, but I think my valve needs adjusting as high is the only setting for a reasonable temp.

I was thinking about it this morning and its likely that my stock probe isn't positioned the same as yours (ie if mine isn't getting flame contact it won't work right) so maybe I just need to play with that a bit.

 

[ScottBailey]

I was thinking about it this morning and its likely that my stock probe isn't positioned the same as yours (ie if mine isn't getting flame contact it won't work right) so maybe I just need to play with that a bit.

I think you can take the metal screen off with one or two screws and some fiddling. I remember it was looking like a huge PITA to make Patrick's mod clean. Regardless of what you do, post a picture of the inside of the box, please.

 

[Jack]

Positioning the relighter probe is critical. It needs to be in a hot part of the flame. My first attempt failed completely (continuous clicking). The second attempt mostly worked, and the third attempt has worked for the last 3 trips.

 

[ScottBailey]

Positioning the relighter probe is critical. It needs to be in a hot part of the flame. My first attempt failed completely (continuous clicking). The second attempt mostly worked, and the third attempt has worked for the last 3 trips.

Jack,

Did you use the factory probe (Dometic/Norcold) or the Atwood re-lighter probe?

SB

 

[pods8]

I think you can take the metal screen off with one or two screws and some fiddling. I remember it was looking like a huge PITA to make Patrick's mod clean. Regardless of what you do, post a picture of the inside of the box, please.

I took the square screen of last night while working on it to ensure the flame was going but didn't remove the upper metal portion of the nozzle to see the actual tip of the probe yet. I was just seeing if I could do the quick version of the install as I was wrapping up some plumbing work.

 

[pods8]

Update: Got back into it this evening and it took about 45min to get it setup like pvstoy's directions. Upon initial firing it'll burp the flame once or twice but then its good to go. The clicking stops within a second of the flame relight and starts as soon as it goes out (not sure how it works but it does for anyone wondering). I tested it out by blowing the flame out multiple times with my compressor air nozzle.

Edit: I should note this one will take a bit of work working with both hands at the same time (the fridge compression area needed to get lifted slightly with a pry bar to remove the burner from under it, screwing down the clap holding the two probes in place while holding the probes in place, etc.) so keep that in mind when budgeting time/frustration if these types of things get to you. Don't want to mislead someone that its as simple as changing a car battery or such but at the same time if you just work though it shouldn't be too bad either. Tinker on!


Here is a pic of the stock probe, as can be seen it didn't really even have an electrode sticking out to get heated up by the flame. Newer models like Scott's might be different.

Here is a view of the combustion chamber pulled out from under the exhaust to install the probe and the probe installed. The flame heats it up fine and it sparks well in this postion, just took a minute or two on the pliers to bend it around. I removed the bracket that comes on the probe with a dremel disk.

Reinstalled under the exhaust without the windshield in place yet.

All wrapped up

 

[Jack]

Jack,

Did you use the factory probe (Dometic/Norcold) or the Atwood re-lighter probe?

SB

I installed the Atwood re-lighter. The probe bracket is spot welded to the probe, so it was a real bitch to position it. I ended up making an aluminum bracket that is bolted onto the probe bracket and then screwed into the hole that held the original igighter.

 

[Stan@FourWheel]

I finally added the re-lighter to my Norcold refrigerator (I have the smaller, refrigerator only model).

I looked at Patrick's install pictures, and it looked so easy & clean in his pictures.

But when I actually got in there to make the part fit & line up over the flame, I had to make a little attachment bracket ("L Bracket" from the hardware store) and bend it just a little.

The re-lighter is designed for a hot water heater, so it wasn't just a "plug & play" installation like the directions stated.

Once I put the little wind shield cover back on, it looked great and it seems to be working great !

But I have to admit, when you see the inside it doesn't look as nice as Particks install (lol).

I wish I had his patience & skills for details.

I was in the "get it done" somehow, someway mode that day.

Over-all I am very happy with the results !

The total install time was probably 2 hours.



.

 

[ScottBailey]

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

Well, looks like it didn't work out so easy after all... <sigh>

 

[Kodachrome]

Insomnia makes you do searches on WTW..

I just ordered this re-light kit, should be here when I get back from my trip, hope it goes well as far as the install goes, I am usually pretty adept at this kind of thing. I am fairly strict on my leveling, I use a combo of two inclinometers mounted to the outside, plus one loose that sits on the counter, floor or my center console and finally my iPhone app. I won't be driving using propane, just when parked. I also strongly consider wind direction and velocity, even go as far as check the weather to help plan it.

On another note, I was trying to figure out what output or cooling is being done on 12V DC while driving. The manual says that the fridge works on continuous, not via the thermostat like on AC. This is for the Dometic 3-way ( RM-2193 ). So is the thermostat knob ( 0-7 ) non-applicable when using 12 V DC?

By the way, I had no problem lighting and using the propane setting on the fridge while parked at the top of Imogene Pass for 24 hours at over 13,000 feet for what that is worth.

I have had my new pop-up for a month and 4 days now, have slept in and used it for 18 days, it is getting close to being fully dialed. Folks like you and threads like these really help me cut to the chase in terms of getting the most out of this new tool for my work, thanks!