Furnace won't light when at higher elevation.

[SteamboatSailor]

Thanks all for your insight, & for taking the time to respond. I think I mentioned in one of my first posts that when the furnace wouldn't light in Steamboat Springs it appeared to be going through all of the mentioned start up steps properly clear to the point of being able to smell propane coming out the exhaust & hearing the "clicking" of the electrode......but then no flame & the furnace would do the "3 strikes & you're out" shutdown. I thought the "clicking" sound was the electrode trying to fire, but not making spark. I had a mobile RV Tech out yesterday to look at it (he had no answers on the reason it would not light, but diagnosed that the "ringing" I was hearing was the blower motor shaft rubbing on the brass bushings it rides in) & he stated that the "clicking" noise was actually the noise that the spark makes at it passes from the electrode to ground. So that being the case, there was gas in the chamber & spark.....so why no ignition? At 6,000 feet in elevation could there be that little oxygen in the air?
Here' the "official" response from Suburban in the form of email sent to Terry Hayes in Heartland's service....

From: Kris Spengler [mailto:kspengler@suburbanmfg.com]
Sent: Tuesday, June 13, 2017 1:16 PM
To: Terry Hayes (email address deleted to protect the innocent)
Subject: RE: RE: Re: 5SFCG4439JE350314 RW 427RW 2018 DOM 4/25/2017 Richard D. Gowins DOP 5/2/2017



Good afternoon,

I’m not sure where 4200 ft. came from but it’s actually 4500 ft. above sea level. Less oxygen content available to supply the burner with combustion air, other variables, such as gas pressure and voltage output of power source, which can also be impacted by higher elevation, can reduce the performance of the furnace. In general use around 5000 feet is no issue. We have had experience with occasional reports of normal operation at Denver’s altitude (my emphasis) with some reduced performance in the surrounding areas at higher elevation. Our furnaces are certified up to 4500 feet. Just an FYI, the Suburban IW60 water heater is rated to 5000 ft. per ANSI code Z21.10.1-2014 under “7.1 High Altitude”. I have attached a copy for your review. Hope this information helps. Have a great day.

Kris Spengler
Assistant Service Manager
Airxcel, Inc – Suburban Division
676 Broadway Street
Dayton, TN 37321
Office: 423.775.2131 EXT 7102
Fax: 423.775.7015
www.Airxcel.com


So, if I'm reading this correctly we're not to expect either the furnace or the water heater to operate correctly at altitudes above 4500' ?? Hmmmmm......

 

[SteamboatSailor]

SteamboatSailor:
I did a websearch on your problem, and saw some interesting responses (with stuff I hadn't heard before) including response #3 about butane being mixed in the propane, which seemed to possibly match your problem. Check it out: http://www.rvforum.net/SMF_forum/index.php?topic=23694.0

Bill, that is very interesting about the butane mix. I filled the propane bottles in OK just before leaving there for return to CO. I wonder....... I'll try to run out our tanks here at the rally & re-fill in Steamboat. Let's hope it's something as simple as that.

 

[gwalter]

We regularly camp at Mueller State Park behind Pikes Peak at an elevation of 9400' and have not had any problems. We have done so over the last 5 yrs. with both our Elkridge, and now our Silverado.

 

[danemayer]

Bill, that is very interesting about the butane mix. I filled the propane bottles in OK just before leaving there for return to CO. I wonder....... I'll try to run out our tanks here at the rally & re-fill in Steamboat. Let's hope it's something as simple as that.

I think Bill is on to something. Here's some more - a bit technical - but the more butane in the mix, the lower the pressure. Sounds to me like that could be the problem.

 

[SteamboatSailor]

I think Bill is on to something. Here's some more - a bit technical - but the more butane in the mix, the lower the pressure. Sounds to me like that could be the problem.

Thanks, Dan. Looking at the chart....if the fill I got in OK had a butane ratio of, say 30% for purposes of discussion, when I was trying to light the furnace when the outside air temp was ~30deg there would have been a substantial drop in pressure. However, now that I think about it, that begs the question of exactly how regulators work. On my split tank system (a tank on each side of the coach) the initial regulator on the "far" side of the coach drops the pressure to a max of 10 psi before passing through the belly of the coach to the primary regulator, then the primary drops the pressure to ~ 6.3 psi before sending it to the appliances. So, if the tank pressure because of the butane mix & low ambiant temps is as low as 10 psi to start, would the initial drop in tank pressure really make a difference at the furnace? Or could it be that the Furnace wouldn't light because of the actual fuel mixture, i.e., that butane doesn't burn as efficiently at altitude?
Whatever the answer, it'll be interesting to see what happens back at altitude with a propane fill purchased there.

 

[danemayer]

A little guesswork, but maybe the 11 " of water column pressure at the furnace gas valve is reduced by the mixture.

Sent from my SCH-I545 using Tapatalk

 

[wdk450]

You know there are 10s of thousands of vacation cabins in the Sierra Nevada mountains of California and they pretty much ALL have propane appliances/heat. I would think that all of these users have locally delivered propane, with a propane-butane mix appropriate to the local elevations/temperatures. Most of us have 2 tank propane systems on our trailers. Maybe it would be a good idea when travelling to stays at high altitudes to have 1 tank empty (or nearly empty), and having that tank refilled in the high altitude area, and switching over and using that tank while at high altitude. I have not heard of anyone having propane issues with using propane obtained in high altitude areas at low altitudes.

 

[SteamboatSailor]

A little guesswork, but maybe the 11 " of water column pressure at the furnace gas valve is reduced by the mixture.

Sent from my SCH-I545 using Tapatalk

Sounds like a reasonable assumption. I'm surprised the Suburban tech didn't suggest looking at the fuel mix. I would think this isn't the first time the issue has come up.

 

[SteamboatSailor]

Well, here seems to be the answer, at least from my experience.....

From the rally we went back to Steamboat Springs & picked up a full bottle of propane filled in Steamboat. We weren't able to use much propane in Goshen, so still had almost both bottles full of propane filled in Oklahoma & Ohio. We left Steamboat & spent a few days in Loveland, CO (elevation ~4700') & furnace worked fine with Oklahoma propane. Now we're just outside of Cody, Wy (elevation ~ 5700'), furnace wouldn't light with OK propane. I switched bottles to Steamboat Springs (higher altitude) propane & furnace fires right up. Who woulda thunk it?

 

[danemayer]

Good to know. Keep us posted if you hit higher altitudes.

 

[JohnD]

We are getting really good mileage out of our propane tanks in our Prowler . . .

We cook with propane, run the refrigerator while on the road, plus run the furnace and hot water heater (HWH) off of it as well (although we do supplement the HWH with electric).

We bought the Prowler in April of 2015 and both tanks were full and did five campouts with it in 2015.

Before we left for the Tucson HOC Rodeo Rally in January of 2016 (two week trip) I took the Prowler to our local propane supplier.

Of course, one tank was still full and the other was down about 1/3, so I had them top it off.

Three more campouts during the summer of 2016 and before we left for the 2016 HOC National Rally in Las Vegas, NV (8 day trip), I took both tanks up to the propane shop and they told me that both were still full!

This year so far we've done an 8 day trip to the Alto, NM HOC Rally and a weekend at the Ft. Collins, CO HOC Rally . . .

Today as I was getting the Prowler ready for a July 4th. weekend at the Central City, CO KOA I pulled both tanks and one is still full and the other felt to be over half full, so I've opted not to bother getting that tank topped off yet.

So in 12 campouts with the Prowler we've used less than one tank of propane . . . I'm guessing probably a 1/2 tank of propane.

 

[LBR]

Aint nobody can compete wit dat fuel mileage...awesome testimony.