EPDM Coatings
rvupgradestore.com Composet Products Custom Yacht Interiors

Author Topic: Furnace Problem  (Read 392 times)

Wingsfan19

  • Posts: 3
Furnace Problem
« on: May 21, 2017, 09:19:45 AM »
Having an issue with our furnace in our 2012 Revere. It will work great for a while and then sometimes it just won't kick in when the temp drops below the set point. If you manually lturn the thermostat off and then back to heat it will work fine again for a while. Thinking I have a faulty thermostat?

Gary RV_Wizard

  • Forum Staff
  • ---
  • *
  • Posts: 60996
  • RVer Emeritus
Re: Furnace Problem
« Reply #1 on: May 21, 2017, 09:47:24 AM »
Could be, or it could be the furnace fails to light occasionally and goes into "lock-down" mode. If the furnace controller shuts off, you have to switch t-stat off/on to reset it. The reasons for failure to light can be any of several, e.g. debris or insect nests in the outside air intake or exhaust, poor LP gas pressure or flow, or weak 12v power (low voltage). A faulty thermostat is well down the list of possible things - it's a pretty simple device and not much prone to failure.

This Furnace Troubleshooting article may help: Furnace Troubleshooting
Gary
--------------
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

Wingsfan19

  • Posts: 3
Re: Furnace Problem
« Reply #2 on: May 21, 2017, 09:59:05 AM »
Thanks Gary. It seems that it's not even trying to kick in (blower motor is not coming on to start heating cycle).  Will have to troubleshoot further.

Alfa38User

  • ---
  • Posts: 5939
Re: Furnace Problem
« Reply #3 on: May 21, 2017, 10:14:36 AM »
No, your description indicates that it is likely  a furnace burner that, for some reason, did not fire up when requested by the thermostat. Did the fan start up for a short time then quit?? The hint here is the fact that, in your description, you said it did start up normally after being turned off - then on again.

The furnace, when requested, will attempt to light 3 times, (3 small clicks of the igniter), if that fails the furnace is locked out and has to be reset by turning off the request for heat and then turning it back on. To  prove this, of course, you have to catch it in action and see if the thermostat is making a request when the temp actually drops. If the fan started then stopped a minute or so later, then the request is being made and you have a furnace ignition problem.

I would connect a voltmeter to the heat request lead and see what happens. By raising the thermostat set point 4-5 degrees, you should see 12V appear on that lead when the thermostat requests heat. Which wire is that? Knowing the thermostat and furnace brands and models might help us find that.

On edit: After seeing your last post, Gary's suggestion makes the most sense in order of checking it out.
« Last Edit: May 21, 2017, 10:17:16 AM by Alfa38User »
Stu
Montréal, Canada 🍁
Snowbird, Naples Florida
Alfa Gold 38 (2000) 5ver (parked!)

"Of course I talk to myself, sometimes I need expert advise!!!"

MikeNNRV

  • ---
  • Posts: 54
  • former tent camper
Re: Furnace Problem
« Reply #4 on: October 02, 2017, 02:36:32 PM »
I need this advice too, but having trouble opening the article link.
Saturday night I had the TT on battery power and the furnace worked ok.  Sunday I plugged in to shore power, but really did not do anything more.
This morning, nothing. No blower, nothing

I looked around for some disable switch but did not find anything.  So far, no response from Forest River.
Virginia is for Lovers
current: 2006 Cherokee 25DD
former: 2001 Coleman Sedona pop up

Rene T

  • ---
  • Posts: 10141
  • Great being on the right side of the grass
Re: Furnace Problem
« Reply #5 on: October 02, 2017, 06:33:30 PM »
I need this advice too, but having trouble opening the article link.
Saturday night I had the TT on battery power and the furnace worked ok.  Sunday I plugged in to shore power, but really did not do anything more.
This morning, nothing. No blower, nothing

I looked around for some disable switch but did not find anything.  So far, no response from Forest River.

I was able to open that link.
« Last Edit: October 03, 2017, 08:55:35 AM by Rene T »
Rene & Lucille & co-pilot Buddy
AKA  Pep N Mem
2011 Chevy Duramax 2500 HD 4X4
2011 Montana High Country 343RL
From the Granite State of NH
& Florida Snowbird in Lakeland FL

Alfa38User

  • ---
  • Posts: 5939
Re: Furnace Problem
« Reply #6 on: October 03, 2017, 08:26:17 AM »
I need this advice too, but having trouble opening the article link.
Saturday night I had the TT on battery power and the furnace worked ok.  Sunday I plugged in to shore power, but really did not do anything more.
This morning, nothing. No blower, nothing


I looked around for some disable switch but did not find anything.  So far, no response from Forest River.

The furnace runs solely on 12V (batteries/converter). This seems to suggest that the house batteries are dead or the thermostat does not have the 12V required to put 12V on the furnace start lead. Perhaps a blown fuse is the culprit.
Stu
Montréal, Canada 🍁
Snowbird, Naples Florida
Alfa Gold 38 (2000) 5ver (parked!)

"Of course I talk to myself, sometimes I need expert advise!!!"

RVfixer

  • ---
  • Posts: 207
Re: Furnace Problem
« Reply #7 on: October 03, 2017, 10:53:23 AM »
We just toured the Smokey Mountain National Park for 7 days and then planned to drive the entire Blue Ridge Parkway camping and attending music events and exploring the areas along the way all the way to Shenandoah National Park in Virginia.  What does this have to do with furnace problems?  Well, I'll tell ya.  We got into an area with lots of stink bugs.  I hate them little ___________ers!  They can get into anywhere they want.  They got around our trailer furnace screen or around the edges of the furnace cover and into the burner area.  You can't clean that out without pulling the furnace out.

The furnace would light for a few seconds then go out...then you could smell stink bugs in the exhaust.  I had a can of canned air and tried blowing into the exhaust area.  With repeated tries of blowing with air and starting the furnace it seemed to burn longer each time...and stink more!  I kept this sequence up but it is a pain as you have to wait for the fan to blow a little before it lights then you have to wait for the fan to stop before using the air and trying again....time consuming, but I got it and the furnace now works great again and the stink is gone.

This may not be an appropriate post here but perhaps the OP could try blowing into the exhaust port on the furnace if he has a source of air.  However, I wouldn't use a high pressure source.

Anybody have any other ideas on clearing debris out of the burner area on a furnace without pulling the furnace out?   

Gary RV_Wizard

  • Forum Staff
  • ---
  • *
  • Posts: 60996
  • RVer Emeritus
Re: Furnace Problem
« Reply #8 on: October 03, 2017, 11:03:37 AM »
Cleaning alternatives depend on the exact model of furnace. In some you can pull off the outer cover and then detach the tube that goes to the outside and brings in combustion air and emits exhaust gases. Others may not be so easily removable.  Newer Atwood Hydroflames claim to be fully serviceable without removal, but I found that was NOT true for the high end model with dual speed fan and Hi/Lo btu output.

Stink bugs get in the tube and block air flow in & out, and it takes very little to disrupt it enough that combustion fails.  The rest of the stink bug problem is simply that they lay on top of the combustion chamber and get roasted, stinking up the interior. However, I saw one where they actually shorted the printed circuit board. Didn't damage it, but they had to be cleaned off to get the baord working again.

If in a bad stink bug area, it probably worth while to run the furnace for a few minutes daily to maybe discourage them from the burner tube. Or at least identify the problem before you really need the furnace!
« Last Edit: October 03, 2017, 11:06:05 AM by Gary RV_Wizard »
Gary
--------------
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

MikeNNRV

  • ---
  • Posts: 54
  • former tent camper
Re: Furnace Problem
« Reply #9 on: October 03, 2017, 04:11:27 PM »
The magic elves visited my TT while I was at work on Monday.  By the time I got back to work on it, all was ok. (I assume that I had not performed the reset with the thermostat properly on Sunday).
Virginia is for Lovers
current: 2006 Cherokee 25DD
former: 2001 Coleman Sedona pop up

 

Hosted by Over The Network