Adjustments on Coleman furnace?

[osgoor]

Purchased our 2005 Itasca Suncruiser in Colorado last year. We were told that should we move to lower altitudes that the hot water heater and furnace would need adjustments for the air/propane mixture. I have adjusted the heater but do not know where the adjustments on the furnace would be. Can someone shed some light on if the furnace does need adjusting and where that adjustment is done.

Thanks

[jesilvas]

You have a Coleman furnace? Never seen one of those.

[grtharris]

Your furnace should be a Suburban. It is a forced draft combustion furnace which I believe do not require any mixture adjustment.

[BFlinn181]

I believe your '05 Itasca is equipped with a Coleman thermostat, but the furnace is a Suburban. If you open the access to it you should see the air mix collar with holes in it around the mixing tube. Loosening the screw and twisting the collar should adjust air flow until you get a mostly blue flame. Unless you see smoke or soot around the exhaust, it's not a critical thing to do every time you change altitude.

[osgoor]

Originally Posted by BFlinn181

I believe your '05 Itasca is equipped with a Coleman thermostat, but the furnace is a Suburban. If you open the access to it you should see the air mix collar with holes in it around the mixing tube. Loosening the screw and twisting the collar should adjust air flow until you get a mostly blue flame. Unless you see smoke or soot around the exhaust, it's not a critical thing to do every time you change altitude.

Thanks for the clarification. Where do I find the access point?

[jesilvas]

Originally Posted by BFlinn181

I believe your '05 Itasca is equipped with a Coleman thermostat, but the furnace is a Suburban. If you open the access to it you should see the air mix collar with holes in it around the mixing tube. Loosening the screw and twisting the collar should adjust air flow until you get a mostly blue flame. Unless you see smoke or soot around the exhaust, it's not a critical thing to do every time you change altitude.

A surbuban furnace with a mixer? That might be an Atwood water heater, but you have to remove an SF or NT Suburban furnace to work on it AND there are no adjustments on those.

[osgoor]

Originally Posted by jesilvas

A surbuban furnace with a mixer? That might be an Atwood water heater, but you have to remove an SF or NT Suburban furnace to work on it AND there are no adjustments on those.

So survey says.... no adjustment

thanks all

[garykk]

I doubt that your MH when purchased had the furnace set specifically for high altitude. I don't ever recall reading anything in manuals regarding adjusting for elevation..

[BFlinn181]

Upon more research, I apologize or saying the furnace had an air mix collar, I was thinking of the water heater. The furnace has a fan blowing combustion air into the ignition chamber, so no air mix adjustment.
All combustion devices (engine, generator, refrigerator, furnace, water heater) are de-rated at high altitude. The only way to adjust for altitude is to change out the gas jets, a troublesome change and seldom worth it if you aren't at that altitude 100% of time.
Another issue in LP gas devices at altitude is if your regulator isn't adjusted or working properly the altitude will bring it out in failing to ignite. Adjustment should only be done by qualified tech with proper equipment. Also sometimes the 'thinner' air will fail to trigger the furnace sail switch and the furnace won't light, again not common, but possible. Because of the less efficient burning and yellow flame at high elevation more soot build up in the ignition chambers of the LP flame devices can cause issues, especially if sensors are coated in sooty deposits. Cleaning these areas is recommended after camping at high altitudes.

[777Rich]

Suggest doing search on this site for furnace propane flue adjustment, there are several good details items