Airstream Forums

Airstream Forums (https://www.airforums.com/forums/)
-   Furnaces, Heaters, Fireplaces & Air Conditioning (https://www.airforums.com/forums/f427/)
-   -   Furnace Not Igniting at Altitude (https://www.airforums.com/forums/f427/furnace-not-igniting-at-altitude-162522.html)

kjloeffler 02-09-2017 07:01 PM

Furnace Not Igniting at Altitude
 
We just bought a brand new Airstream 16' sport in Denver. Everything worked great when we picked it up and heater was cranking out heat. We drove it 4 hours to our home in the mountains at 8100' and now the furnace will not ignite. At first I thought it was that the propane was too cold (down to 20 degrees lately) but today it was 50 degrees and had the same problem. The blower will push out cold air for just over a minute, then it shuts off. You have to manually flip the switch off to on and do this around 10 times before it will (sometimes) ignite and stay on with warm air. It seems like it's less the propane temperature and more the pressure (lower pressure at altitude). I did get it to work a couple times, so I know it does work, but usually just shuts off when I try to turn it on. I have talked at length with the service department in Denver, but we have not figured out a good solution yet. He walked me through all the other systems and the stove, hot water tank, and refrigerator all seem to work fine and ignite with the same propane. Like I said, it's brand new and our first Airstream, and we haven't taken it anywhere else yet to try it lower elevations.

Just wanted to see if anyone has any ideas of how to get the furnace to ignite while we have it at home at 8100' in cold Colorado! Brand new, so it should be functional and should not need cleaning...

Piggy Bank 02-09-2017 07:50 PM

You might consider contacting the heater manufacturing and asking them about use at altitude. They may have faced this issue before.

Essentially, it sounds like your blower works OK, but perhaps the ignighter isn't sparking, or the flame sensor is not sensing flame and then is shutting down for safety.

It may or may not be related to the altitude. Do you find any possible info in the owners manual of the furnace?

Bigventure 02-09-2017 08:01 PM

Furnace not igniting at altitude
 
What you need to do is adjust the propane regulator. The big round device between the tanks. It has a big cap on it. Unscrew it. Inside is a big screw. Tighten it up to raise the pressure.

Piggy Bank 02-09-2017 09:31 PM

Bigadventure, that's some good info to know!

TG Twinkie 02-09-2017 11:06 PM

Unless you have a manometer and know what you are doing DO NOT attempt to adjust the regulator.
Propane systems are nothing to mess with.

DaveMc 02-10-2017 05:03 AM

Quote:

Originally Posted by TG Twinkie (Post 1910208)
Unless you have a manometer and know what you are doing DO NOT attempt to adjust the regulator.
Propane systems are nothing to mess with.



^^^^^^^THIS!!!!! It would be a very dangerous idea to adjust the pressure regulator for 99.99% of us RVer's. A local AS'er sent us a link in our group text the other evening. I thought it was great advice and am glad to pass it along. Spend time looking at other articles on the website. Bookmark the site and read them all as time allows.

Hopefully this link works. If not, googling "RV Doctor Propane Pitfalls" will get you there. Stay safe!

https://www.rvdoctor.com/2001/01/avoi...ystem.html?m=1

GettinAway 02-10-2017 06:36 AM

We've run our furnace at various campgrounds all over CO. Last summer we were up above Steamboat Springs at Pearl Lake. It has to be at 8,000 or higher. No issues at all with running the furnace. I would guess something is off with your unit. I would also not go into the propane regulator, as advised above. It's a return trip to the dealer, which is a pain in the backside.

joqin 02-10-2017 09:21 AM

furnace
 
I know it's a long shot ,but check for spider webs in the burner tube. I had the same problem with a water heater. had to tease it out with a tooth brush. compressed air just blew it around ,but didn't unstick it, and it lowered the gas flow just enough to cause the the problem.
joe q in minnesnowda

Ted S. 02-10-2017 12:41 PM

Very interesting. I do not have a solution, but I had the exact same experience with my brand new trailer in the Bighorn Mountains up high on the pass.

When we got down in elevation, it worked fine.

Minipad 02-10-2017 12:46 PM

I too live in the mountains and have found that it may be air in the lines and not a pressure issue. You shouldn't have to adjust the regulator. I can usually get the air out by running the stove for a bit. It may flicker some which is a good indication that you have some air in the lines. If your furnace isn't lighting, your fridge and hot water heater may be having some trouble as well. Another thing to try would be to disconnect / reconnect the tank(s) a couple of times. Run the stove in between. Once you get the air out, you should have no problems. I haven't had to purge my system in over three years with constant changes in elevation. Good Luck.

h2ocoolerman 02-10-2017 01:29 PM

As a HVAC tech I can tell you that altitude can have a effect on propane or natural gas burners. There are adjustments points on the gas valve itself to adjust the fuel air mixture going into the burner. Most are set up for sea level to some altitude. Going higher in altitude means less air and some times the gas valve will need adjustment, but this needs to be done by someone with both the knowledge and tools to do the job right.

Wolf Alaska 02-10-2017 02:17 PM

I had difficulty with the water heater staying lit while camping @ 7,300 feet. After running for a while, the pilot light & main burner failed. Leaving the door open solved the problem. The air vent provided in the door wasn't big enough & didn't supply sufficent thin air to support the burner.

Altitude affects gensets, water heaters, furnances, & propane refers. Each mfg. provides specific means to cope.

Welcome to the RV hobby where you can obtain arcane knowledge that those of us, on this great forum, will applaud & no one else will care about at all.

So, go & become expert on your AS furnance. It is not really a good DIY appliance like a water heater, but the more you learn about it the better.

Oh, & don't forget to come back & tell us ! We'll appreciate your new knowledge �� .

Let's Roll !
Wolf. ��

crispyboy 02-10-2017 02:28 PM

It is likely the propane regulator will need to be adjusted by someone with a manometer. If it's brand new then take it back to the dealer.
The toughest part I found is making up the tool or you can purchase the tool and do it yourself.
I made my own tool and checked the regulator on my trailer back over the summer which needed to be tweeked ever so little. Higher altitude will need to be closer to 12-13" water column with all the appliances running.

franklyfrank 02-10-2017 03:58 PM

Quote:

Originally Posted by kjloeffler (Post 1910115)
We just bought a brand new Airstream 16' sport in Denver. Everything worked great when we picked it up and heater was cranking out heat. We drove it 4 hours to our home in the mountains at 8100' and now the furnace will not ignite. At first I thought it was that the propane was too cold (down to 20 degrees lately) but today it was 50 degrees and had the same problem. The blower will push out cold air for just over a minute, then it shuts off. You have to manually flip the switch off to on and do this around 10 times before it will (sometimes) ignite and stay on with warm air. It seems like it's less the propane temperature and more the pressure (lower pressure at altitude). I did get it to work a couple times, so I know it does work, but usually just shuts off when I try to turn it on. I have talked at length with the service department in Denver, but we have not figured out a good solution yet. He walked me through all the other systems and the stove, hot water tank, and refrigerator all seem to work fine and ignite with the same propane. Like I said, it's brand new and our first Airstream, and we haven't taken it anywhere else yet to try it lower elevations.

Just wanted to see if anyone has any ideas of how to get the furnace to ignite while we have it at home at 8100' in cold Colorado! Brand new, so it should be functional and should not need cleaning...

For what its worth, we used our furnace a number of times at 8,700' without a problem. The stove as well.
Did you by chance try it at a lower altitude ? Might want to give that a try to be sure.

guskmg 02-10-2017 04:15 PM

Probably, your furnace "sail switch" is not getting enough air flow so as to allow the fan air to push open the sail and close its switch. Thus, the furnace can not finish its ignition cycle by allowing electricity to open the gas valve. The sail switch has to be completely free moving to work especially at altitude in the less dense air. A bent or dragging sail is the cause. I have had the same problem and sometime after a number of thermostat on-off switch cycles it will work, but to fail the next time the thermo calls for heat. A new sail switch only costs $7 or $8, but it can cause you and your rig to freeze up especially during a Colorado winter. If it is under warranty any furnace authorized dealer can fix it for you.
guskmg

James Ferens 02-10-2017 04:47 PM

We've been in our 2012 22 ft Bambi at 8600 ft in Colorado for 6 months with no propane furnace issues - the only times that our furnace does what yours is doing - kicking on - fan runs for a minute - kicks off - is when the lpg bottle is empty ... maybe?

James Ferens 02-10-2017 04:58 PM

We've been at 8600 ft in Colorado for 6 months full timing with no furnace issues in our 2012 22 ft Bambi - the only times that our does as you've discribed is when the propane bottle is empty..... maybe?

Bigventure 02-11-2017 08:21 AM

I guess I should have included a safety warning when I said to "adjust the regulator".
I am a HVAC Pipefitter for 35 years and responded quicky to the tread.

I assumed some mechanical aptitude on the part of the original poster.

I forgot that a lot of people don't know how to use a screw driver and are not capable in any way of working on this system.

To those people DO NOT ADJUST YOUR PROPANE REGULATOR!

By all means take it back to the dealer it under warranty.

Now to those who feel comfortable with a screw driver.

When I made the statement to raise the pressure, I wasn't referring to cranking the screw in fully. Just give it a 1/4 turn in. The main regulator has limits. It will not send pounds of pressure into the system. You can see the difference on a standing pilot. An example would be the oven. The pilot will increase in length a little bit. Also the stove top burners will be a little longer. Sometimes the pilots won't stay lit because the flame is not making contact with the termocoupling.

The furnace does not have a pilot. It has an igniter. The fridge has a pilot with a auto-lighter.

The absolute by the book way is to use a manometer. And have a certified tech do the job.

Ted S. 02-11-2017 09:26 AM

Well I'm hesitant to mess with it, but if you google around it looks like many RV'ers are doing it. I think it can be done safely if you use some common sense.

Here is a cool video I just found on the topic:

https://youtu.be/RyTx8VIE_kQ

I think I'd like to learn more about this. If not for repairs, just to test for proper function and leaks. Maybe buy an actual manometer. I am convinced elevation affected our unit and the OP's, and the qualified folks here seem to support the idea. We had all sorts of issues with tires, prepackaged food, etc. going from sea level to 10,000'.

I figure before I really mess with regulator, I'll just throw it in the garbage and put a new one on.

franklyfrank 02-11-2017 11:12 AM

Quote:

Originally Posted by Minipad (Post 1910375)
I too live in the mountains and have found that it may be air in the lines and not a pressure issue. You shouldn't have to adjust the regulator. I can usually get the air out by running the stove for a bit. It may flicker some which is a good indication that you have some air in the lines. If your furnace isn't lighting, your fridge and hot water heater may be having some trouble as well. Another thing to try would be to disconnect / reconnect the tank(s) a couple of times. Run the stove in between. Once you get the air out, you should have no problems. I haven't had to purge my system in over three years with constant changes in elevation. Good Luck.


Ditto !


All times are GMT -6. The time now is 02:48 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.