I have a coleman evcon furnace in my double wide. Yesterday it ran fine, today not so good. I can see the "glow plug" light up and then ignite the unit so there is flame and the blower motor turns on... but after a 2 minute run it shuts back down and the air is less then warm during that 2 minutes. I have been told its my centrifical switch, my heat sensor, a cracked heat exchanger, or the anticipater on the tstat. I have no idea where to begin.

Also this may be of some relevance, My vent cap on the roof got blown off in the last storm. It has been replaced as of yesterday.

Please Help... its Sunday... no one open and cold as heck!

I have a coleman evcon furnace in my double wide. Yesterday it ran fine, today not so good. I can see the "glow plug" light up and then ignite the unit so there is flame and the blower motor turns on...but after a 2 minute run it shuts back down and the air is less then warm during that 2 minutes. I have been told its my centrifical switch, my heat sensor, a cracked heat exchanger, or the anticipater on the tstat. I have no idea where to begin.

Also this may be of some relevance, My vent cap on the roof got blown off in the last storm. It has been replaced as of yesterday.

Please Help...its sunday...no one open and cold as heck!

I should also add that this is a propane furnace

Worked yesterday, vent cap replaced, not working today? Here's a good place to start...

Just because it is Sunday does not mean you cannot get on site service. Most service companies do have emergency service. You'll pay a lot more though.

Maybe the repair guy from yesterday had the wrong idea of a "cap".

You thinking he left his hat on the flue vent?

You know how those damn Buckeyes fans are... wanna leave their mark everywhere!

Let me re-try typing the events in order since I seem to be semi-illiterate on the computer today.

Furnace worked fine yesterday, today it didn't, then noticed that the vent cap had blown away and replaced the cap today, still not working. As I said, have been told of many different things it could be, just wondering where to start my process of elimination and I don't have the money to call a tech.

Have you checked the air filter lately? If it's clogged the unit will overheat and short-cycle.

The filter is on the main panel of the door. With the door completely off the furnace still short cycles

With so many possibilities, you'll have to bear with seemingly useless suggestions. Troubleshooting starts with the most obvious and progresses from there. Do you know if the unit is equipped with a diagnostic status indicator? This is usually a LED on the main circuit board.

Yes. The indicator is showing 1 blink every few seconds which indicates ignition failure according to the code sheet on the furnace

Based on your original post and the fault code given, it sounds like a dirty/oxidized flame sensor. These are located near main burners, usually look like a steel rod, ceramic insulated, with a single wire. Locate, remove, clean with mild abrasive, re-install and try heat again.

OK... cleaned the flame sensor with 220 git sand paper and reinstalled... same cycle... 3 tries and then ignition failure code.

I now have also noticed a faint smell of propane coming from the front of the moduale that the flame sensor is connected to just before flame out.

Could this be a bad gas cellenoid or a closed valve... or does it seem to be a heat exchanger problem?

How many burners? Do they all light? Observe flames from start-up. Do they start straying or blowing around when the blower starts? If so, is the sensor still bathed in flame, or exposed?

Only 1 burner, if the burner is the piece that glows orange before ignition... and yes the flames do blow around, the sensor isn't totally bathed in flame but there is flame on it so it is semi exposed

only 1 burner, if the burner is the piece that glows orange before ignition...and yes the flames do blow around, the sensor isnt totally bathed in flame but there is flame on it so it is semi exposedThe glow before ignition is the ignitor. The burner(s) produce flame. You may have a leaky heat exchanger. Get it checked by a pro ASAP.

I was afraid of that. I have been told its time for a new furnace if the heat exchanger gets leaky. So now I'm really screwed but thanks for all your help

Check the warranty status of the unit before committing to replacement.