Dometic stove doesn’t light at higher elevations

Tabnero

My 2021 tab 320s alde and dometic have worked well at 7500 ft as I posted a picture earlier in this thread. if you have opened the regulator at altitude too fast, it will not light and you have to close it and wait a while before retrying. I open it in a very, very slow, stop slow, stop method and it works. My fellow camper at 7500 ft had the same problem in his big expensive TT and I was able to help him with the same process. you might try it first

WayneW

We live at about 3000 ft.  When I read this string earlier this summer I thought it must be some kind of user error - why would a stove not work at higher altitude.  Then we camped at 7000 ft - and the stove would not light!  Dang.

I did what many recommend here.  I closed the valve on the propane tank, relieved any pressure by opening a burner valve on the stove, closed the burner valve, then slowly opened the propane tank valve.  And the stove worked.  It worked for the remainder of the 11 day trip with elevations ranging between 750 ft (Lewiston Idaho) and 8000 ft (Little Lost River drainage, Idaho).  

I think the first 1/8 turn or so is critical.  After that I'm not sure it matters.  If the pressure hits the safety valve too fast, combined with reduced atmospheric pressure at altitude, it shuts down.  But now I'm just guessing.

markhanks

Success!  As mentioned in a previous post our Dometic stove (installed in 2021 Tag CS-S) was not working at elevations over 4000', we live in CO at 10,200'.  I bought a manometer and tested the units LP pressure at the aux gas location on the aft end of the trailer.  It measured 15 w/c three points higher than recommended for the stove and most gas appliances.  It should be noted that even at this higher pressure the stove would not emit any gas at the unit and yet when I took the unit out and removed the gas line - there was indeed gas coming from the line.  Thus, at the regulator I turned down the pressure to 12.5 w/c and presto the stove works, no sputtering or anything, just a nice hiss of gas emitting from the burners and they lit immediately.

My hypothesis is that the Dometic stove has a shut off valve within the unit that is tripped at higher pressures and does not allow any gas to flow through the unit to the burners.  Probably a safety issue so the flames do not become too large which could be a potential fire danger.  Higher LP pressures are achieved because at higher elevations there is less atmospheric pressure restricting the flow of gas.  By turning down the regulator one can bring down the pressure going to the stove to parameters within the mystery valve Dometic has within the unit.  

So if you're having an issue at elevation, buy a manometer for $25 and adjust your regulator yourself.  I tried everything else in this blog, turning on the gas valve slowly, purging the system, trying different LP tanks and nothing worked until actually measuring what was going on and correcting it. Don't bother calling Dometic, they will stop you at the door and provide no information.  I'm sure a liability issue.  

It will be nice to use the stove that came with camper again!

pthomas745

@markhanks thanks for the update.  I've googled around and discovered the whole nanometer measuring process, but you might be one of the first here to actually do it.  I also never expected to hear "high" pressure to trip out the appliances. 

Can you go over for us the nanometer measurement process? 

There was one other mention of the pressure regulator adjustment working for an owner, way back in 2016.

https://tab-rv.vanillacommunity.com/discussion/2867/propane-regulator

markhanks

The manometer process is pretty straight forward. It's just a measurement device for low pressure gas applications.  They primarily measure in increments of "water column". I think the recommended 12 w/c is like .5 psi.  I bought a low tech/anolog gauge, about $50 on Amazon.  There are expensive electronic versions but I figured for the rare occasion I need the thing...the batteries will have run out.  The gauge will reside in the toolbox on board the T@b.  I expect when we do go down in elevation, I'll need to turn up the pressure regulator to get any kind of performance from the stove.

I too was surprised to have never read about this solution.  I have read of varying theories on whether LP pressures increase or decrease at altitude (assuming temp is stable).  I finally got tired of reading multiple thoughts on theories and decided I'd find out through direct testing. It's as clear as day to me now.

The Manometer comes with a rubber tube which I connected to a quick disconnect LP brass connecter on the aux LP line on the outside, stern of the camper.  The other end of the quick disconnect was barbed and would accommodate the rubber hose that came with manometer.  Click it in, connect the manometer to the hose and you get an accurate measurement of what the regulator is allowing to flow through the system.  I believe this is the adjustment the Alde furnaces are adjusting for with the "high altitude" setting.  Note, now that I've made the adjustment to the regulator, I won't set the Alde on the "high alt" setting.

Then it's just adjusting the regulator, I had to turn the regulator adjustment screw about 1.5 turns to drop pressure 3 points of w/c.  BTW, the adjustment screw is behind a black screw off cover on the regulator...which is under a white plastic decorative cover.  Remove all of that to get to meat of the matter.  I sure hope this helps others as it's super frustrating to not get the stove up and running...when the solution, really, is right there.

pthomas745

Thanks!  I went down the rabbit hole on the manometer when I read about the owner in Santa Fe and a quick "mysterious" adjustment fixed his fridge.  We have good ways of measuring batteries and water tanks, can change the Alde fluid...but propane issues just end at "it don't work".  I understand why any company would be very cautious over discussing propane...but a little bit of help sure would be nice.  I'm wondering if any HVAC or propane business would consider this simple measurement and adjustment just a normal thing to do.

Sharon_is_SAM

@markhanks - how is the Alde on LPG after your adjustment?  Do we even know the Alde LPG requirements?  Any impact on the LPG quick connect port for operating an outside grill?  

markhanks

Those are great questions Sharon.  It is my understanding that most LP appliances prefer around 12 w/c for pressure.  It's what the LP regulator (mounted in trailer box up front) does, step down the pressure from the tank to a consistent 12 w/c the all the appliances installed in the trailer or accessories run on.  It is my assumption the Alde, and anything plugged into the quick disconnect port will run fine with the new adjustment...but to be honest I have not done the empirical test yet.  I think I will today.  My assumption is that the Alde, which ran fine at the high elevation setting, will no longer need to adjusted for high el.  I'll give it a test today. 

markhanks

PThomas,  I called a local T@b dealer in Salida Co (8500') and spoke with the service manager there re the issue.  He expressed frustration with Dometic and suggested I increase pressure at the regulator.  It was another moment where I got conflicting info and decided I just needed to find out where my system was at and adjust accordingly...Hence the Manometer process.  I'm sure there's a fluid and gas dynamics eng out there who can parse through all this and explain the difference between flow and pressure, etc. etc. but this, so far, has resolved a frustrating issue.

pthomas745

Salida!  Friends live up near Buena Vista, and I've been there many times.  Hope everything is well at Holiday and over at the "Hungry Truck!" 

Thank you for getting to the measurement issue.  I have a comment back in October in this thread with discussions about the regulators and how they are supposed to work.  I ran into this web site that closely discusses the ins and outs of propane regulation in a trailer.  Propane devices can shut off for "not enough" propane pressure and because of "too much" propane pressure.

http://www.rvdoctor.com/2002/01/what-pros-do-propane-system.html

I don't believe that an owner can ever get any answer whatsoever about their propane delivery in the trailer, except from a qualified professional.  We have seen it in this thread: dealers and manufacturers simply cannot respond.  Probably for good reasons.

Without proper measurement of your "water column inches" from the propane regulator, there is no way of knowing what is going on with your propane accessories.

Find a local "propane professional" and ask if they can measure this for you if you are having problems.

burkeks

Just now getting ready for some higher elevation camping. Do you know of a source or link to the manometer used to measure pressure at the auxiliary propane outlet. It seems it would need a quick-connect compatible with the T@B outlet. The big "A" has many products at many price points. Thanks

Kevin_K

We just returned from a cross country trip ourselves. From the east coast, up to the Rocky Mountains, and another place with a base camp of over 9,000 feet. Didn't run into any issues except for the Alde system, but I can now assume (after reading the forums and trying to figure out another issue) that it was related to a failure to make the change in the Alde control panel (that resulted in a 'thumping' sound that we encountered). We'll remember for next time.

However, we did eventually run into the issue with our Dometic stove. It happened upon our return trip from the west coast (800 feet elevation, if that). Once we got back up in the mountains (North Cascades) and moved into Idaho, it stopped working altogether. There was no hissing sound coming from the stove, but the Alde and frig worked fine. I tried all the immediate actions referenced in the forum, but nothing worked. I thought it might be the GoFlo regulator, but squashed that as two other appliances were still working. I made minor changes to the regulator to see if it would work, but didn't. I set it back to original setting and simply used our spare one burner stove that we took on a kayaking trip.
When I got home, I ordered the manometer and made sure the pressure was set to 12.5 w/c. Bled the entire system, but stove still not flowing. 
I took the stove out and took apart the regulator and low and behold, found the regular diaphragm 'stuck'. I pushed on it a bit and it finally was set free and wiggled freely. I put the stove back together and Voila!, it worked!
So I caution anyone about trying to 'fix' something that doesn't exist. Had I went with my initial gut feeling, I wouldn't have wasted so much time. However, I didn't have the correct tool to take the regulator apart (which required a 20 torx bit with a hole in the center).  
Somewhere along the line, the checkball in the regulator was sealed. Although I did release pressure from the system (turning off the tank and releasing pressure through the quick disconnect, opening valves on stove), it wasn't enough to reset it. Only by taking it apart and physically pushing on the diaphragm was I able to get it working again.
This was on a 2021 TAB 400 BD.

WayneW

We just had a similar experience. Trip from Idaho to Michigan and back. No problems until the last night in Montana at 5000’. None of the “regular” fixes worked. I too broke out the backup stove to get the coffee going. The Alde was working fine and the tank was ~70% full. 

When we needed a second pot of coffee I tried the stove just for the heck of it and it worked!  I had released pressure by disconnecting the propane tank and opening the stove burner valve in my earlier attempts but it didn’t immediately help. It was only after sitting for 20 minutes or so that it lit. Frustrating! 

So for clarification, @Kevin_K, you are talking about the regulator in the tub by the propane tank, correct?  Not some internal regulator or safety device in the stove itself. Thanks. 

burkeks

The puzzling thing about this is that it appears many if not most Dometic D21 stoves work just fine at altitude. Most reporting stove issues say the Alde worked ok. This increasingly points to the secondary regulator inside the stove…either it is more sensitive than the primary regulator in the tub or gets stuck as in the previous post. RV parts suppliers list a Dometic stove regulator for a little over $40. I can’t yet confirm online if it fits the D21. 

Kevin_K

WayneW said:

We just had a similar experience. Trip from Idaho to Michigan and back. No problems until the last night in Montana at 5000’. None of the “regular” fixes worked. I too broke out the backup stove to get the coffee going. The Alde was working fine and the tank was ~70% full. 

When we needed a second pot of coffee I tried the stove just for the heck of it and it worked!  I had released pressure by disconnecting the propane tank and opening the stove burner valve in my earlier attempts but it didn’t immediately help. It was only after sitting for 20 minutes or so that it lit. Frustrating! 

So for clarification, @Kevin_K, you are talking about the regulator in the tub by the propane tank, correct?  Not some internal regulator or safety device in the stove itself. Thanks. 

The regulator in the tub works just fine. I'm referring to the regulator that is part of the stove. 
There are screws in the corner (T20 torx tamper resistant) that need to be removed. Under this cover, there is a red diaphragm and a spring in the cover. If you touch the center of the diaphragm (metal portion), it should instantly move freely and return. If not, there is a connected shaft with a check ball underneath, and additional pressure on the diaphragm will unseat the checkball from its seal. Once free, put back together. It worked for me. This is probably what they mean when the regulator 'freezes' (the checkball sticks to its seal). Don't take this literally as I did when I tried to put a warm cloth around it to thaw it out. I guess mine didn't release over time because the check ball adhered to the seal and the spring pressure wasn't enough to release it. I did try to tap the casing initially to try to free anything inside when the problem first appeared. That wasn't enough.
After looking over this photo, it appears the regulator is needed so it can go from the 12.5 WC to 10 WC. Otherwise, it wouldn't be needed at all.
Once again, this is for the 2021 TAB 400.

WayneW

@Kevin_K  Thanks for the clarification. I’ll take a look at that.

pthomas745

This problem seems to be popping up more and more.  On the FB page the last couple of days, several perfectly fine stoves that have been cooking just fine...suddenly will not light.

sdm

We just purchased and installed the Dometic drop-in stove in a Sprinter van, and I have a solution to this problem that we want to share. I'd read all the reviews here, on the Dometic site and at Amazon about the lighting and altitude issues. We live at 4000 feet, and often camp up to 8000 feet. Our situation is that we were replacing a Wallas diesel stove/heater that was always fritzy and slow to ignite. We already had a hole in the countertop and couldn't use a smaller stovetop. The counter cutout matched the Dometic size almost perfectly, so that's why we went with it despite all of the reported issues. We purchased the stove at Amazon, through a 3rd party seller. When we received the stove and tested it with our propane tank, we immediately encountered the same issue as everyone else: propane running fine to the regulator under the stove, then not being allowed out to the burners. After many tries and different very slow open/close/opening of the tank valve, I was able to get the stove to ignite and then burn with a very weak flame on one burner at a time. It appeared that we got a stove with a dud regulator like many people on this thread. I contacted Amazon to try for an exchange, and was told they did not have the product available for replacement so their solution was to refund our money and we could keep the stove. I did some searching for another stovetop, but the cheaper stovetops (which all got great reviews) were still too small for our cutout. In that search process, I discovered that those stoves don't have a regulator--instead, the consumer purchases a regulator and attaches it at the propane tank, hence the great reviews since no one was having this problem with a built-in regulator. Since we had nothing to lose at this point, we decided to try to get the offending regulator off the Dometic stove. That took about 5 seconds with an adjustable wrench and a channel lock. At that point we attached the stove to the propane hose, purchased a regulator at the hardware stove and attached that to the propane tank, and the stove instantly worked perfectly. I tried to post this as a review to the Dometic site as well, but I am dubious that they will run it. I hope this helps everyone who is dealing with this issue!

Sharon_is_SAM

Sweet!  @SDM - can you share this with nuCamp?  Help@nucamprv.com

Maxcamp

We posted about stove failure at altitude in 2021. 

The Regulator blockage is not limited to 4500 ft altitude!  After a day of up and down driving through TN mountains at 2600 to 800 ASL, we found zero gas pressure to stove despite Alde and external port working. Temps jumped from 23 to 76F. 

 Several rounds of tank disconnection and line purging did not help.  Eventually recalled advice to reopen propane tank valve very slightly and slowly... and recovered stove Regulator function.
I wonder if combination of temp swings and elevation swings approaches a 4000 ft elevation change in pressure?

dnordahl1

I wonder if there is a single Dometic product that isn't plagued by some design issue that would be trivial to fix, but never will be. I've invested probably several hundred hours now getting Dometic, Jensen, and Camco products out of my TAB@400 after they keep failing every couple years or are too maddening to use.  I probably won't buy another RV because I don't have the patience to go through this process again or the willingness to pay to have a new RV custom built without these brands. 

Slackers

We haven't had as many problems as you with the Dometic equipment. Our Jensen radio is a different story. The buttons stick, FM results in silence 9 of 10 times it's engaged (via push-button or Jensen app) and often only the left speaker works. It would have been better if nuCamp offered a decent Bluetooth speaker (as they do now for their Tags).