Furnace Problem 2014 sunset trail 270b

wayne bair · 12-14-2015, 10:53 AM

Last time out turn heat on and worked fine first night. Got cold at night got up and furnace was running but not shutting off Played with thermostat Lowered it it shut off, then raised it back up . Everything worked fine for awhile. It started same thing again. Thinking it could be thermostat or maybe getting low on propane.. Any thoughts. Thanks

Joedh2 · 01-01-2016, 07:20 PM

I am having the same problem but I just filled both tanks so I know it is not a propane problem. My furnace is running - well at least the fan is. Thermostat is set to auto and set to heat. Cool air is coming out of the floor vents and and from the exhaust outside? All other propane appliances are working. Any ideas on what I can do?

harley · 01-01-2016, 09:35 PM

try taking it off auto and put fan to low. If I remember correctly.

Joedh2 · 01-02-2016, 11:36 AM

Tried it. No go. Guess I'm going to have to take it in and get serviced.

Joedh2 · 01-05-2016, 12:56 PM

Ok, so before taking on the arduous task of bringing my ST26RB to a repair shop to fix my furnace, I decided to do some internet sleuthing to see if I could learn more about what may have caused my furnace not to ignite. I fond a few articles describing "Furnace Lockout Mode", which I believed may be related to my problem. I have never heard of this before but what I learned is the furnace will go into lockout mode, if after 3 attempts, the propane does not ignite in the furnace chamber. This is a safety feature built into the circuit boards of RV furnaces to prevent explosions due to the chamber possibly filling up with propane. In lockout mode, the air blower will come on when the thermostat reaches the threshold of the temperature setting to heat up the trailer but the furnace will never ignite. This is exactly what was happening in my trailer.

This has never happened to me before and being a seasoned camper of several years with a travel trailer, I never gave this a second thought. So yesterday, after reading up on lockout mode, I decided to give the furnace another try and sure enough.... it fired right up and continued to work as normal, turning on and off and heating the trailer up perfectly!

After much relief of not having to take the trailer in for service, I informed the wife and we talked over a few things where we may have contributed to the lockout mode during our campsite setup in addition to our propane line problem.

Here is what we discovered.

1. The hot water heater was turned on 1st. (Normally we don't do this first)
2. Thermostat was turned on to heat (Again - normally we don't do this but I am going to blame the wife for jumping the gun - yeah it was very cold this day!)
2. Opened the valves on the propane tanks - Notice the hot water heater came on immediately after a few turns.
3. Smelled propane near the tanks - thought it might be from the hot water heater igniting but discovered that the hoses from the propane tank to the auto-changer regulator were leaking and hissing. Window on the regulator showed "RED". Had just enough propane pressure to power the water heater but not enough to fully engage the diaphragm on the regulator to change from red to green. Sprayed some soapy water on the hoses and confirmed leaks on both.
4. Turned off the propane tanks immediately. Turned off the hot water heater. FORGOT TO TURN OFF THE HEATER - DUH!
5. Bought new hoses. (THANK GOD FOR CAMPING WORLD being open on New Years Day!) Furnace came on a few times while I was on my way to Camping World. <----Furnace lockout!
5. Installed the new hoses - opened up the propane tanks - regulator changed from Red to Green - YES!
6. All appliances working except Furnace
7. Beat head against side of trailer after several hours trying to get the furnace to work. Gave up and used the electronic fireplace.

If I had only known....Recommendation from several articles on the internet:

Open the propane tanks FIRST and INSPECT ALL PROPANE LINES before turning on any appliances. This provides sufficient pressure for the auto changer diaphragm on the regulator which supports two tanks to function properly. An open propane appliance during this step may create a fire hazard and may not provide sufficient pressure for the auto-changeover feature to work properly.

To get the furnace out of "Lockout Mode" turn off all appliances, disconnect RV from shore power and from battery power. Zero power will reset the furnace circuit board. Wait a few minutes and re-connect power.

I know that was a long winded post but I hope this helps anyone else who may encounter the "Lockout Mode" with their RV furnace.

Even a seasoned camper can learn a few things down the road!

**mark5w** · 01-05-2016, 08:11 PM

Glad you found the issue and you're detailed explanation is beneficial to all of us.

**Lloyd** · 01-06-2016, 08:44 AM

Hey Joe, that was a good write up!

Thanks for sharing and posting it. You are absolutely correct---even a seasoned camper can still learn a few things.

coastn · 01-07-2016, 11:54 AM

I for one learned something new. Thanks, Joe!

DerwoodF350 · 01-11-2016, 11:25 PM

Excellent post. Thank you.

Poppabear · 01-18-2016, 11:54 AM

Awesome post Joe, I would have never known about the "lockout mode" and could totally see me or my wife running to turn the furnace on first thing and end up in the same boat you were in. As always the information on this forum can be invaluable to us new comers!!

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