Visit our Popular Forums

BessieB · 09-05-2016, 10:17 AM

I could not find any previous threads so while I'm searching..... we put in a new motor for our furnace but the heat doesn't kick in, it just blows cold air. I read on a thread that it could be the circuit board. Procrastinating husband just brought in the circuit board. I suggested making sure there is nothing on it and hook it back in firmly and see if the furnace heat kicks on. What are further guidances?

featherbedder · 09-05-2016, 11:41 AM

Quote:

Originally Posted by BessieB

I could not find any previous threads so while I'm searching..... we put in a new motor for our furnace but the heat doesn't kick in, it just blows cold air. I read on a thread that it could be the circuit board. Procrastinating husband just brought in the circuit board. I suggested making sure there is nothing on it and hook it back in firmly and see if the furnace heat kicks on. What are further guidances?

Igniter or gas not turned on or line plugged thermometer sounds like working as fan turns on. I had same prob. wouldn't ignite, was defective circuit board replaced no prob. since.

BessieB · 09-05-2016, 12:08 PM

So what trouble shooting did you do to see if circuit board was the problem? We have it out so don't know if that is the problem. But that is the direction I am thinking.

featherbedder · 09-05-2016, 12:47 PM

Quote:

Originally Posted by BessieB

So what trouble shooting did you do to see if circuit board was the problem? We have it out so don't know if that is the problem. But that is the direction I am thinking.

Sorry I did not diagnose prob. Was in Fla. in Dec. when happened AS dealer where we were, fixed w/out waiting.

BessieB · 09-05-2016, 12:52 PM

So now my husband is wondering which way the plug goes into the circuit board. If one puts it in one way or the other will anything bad happen? He's wondering if he did that right. The plug has 3 wires. The circuit board on top says power and the bottom is ground. White wire and a yellow wire with a red in between. Any help and input is appreciated.

lewster · 09-05-2016, 01:32 PM

Look inside the 'plug'. You will see contacts on one side. Those must connect with the metal 'contacts' on the igniter board.

There should also be a slot in the board and corresponding plastic channel in the plug. Match them up and you're done.

Lew Farber

Boxite · 09-05-2016, 01:58 PM

I realize this isn't very funny to the OP...(I've got this vision of a husband being sent repeatedly out to the garage to "fix" something, while the wife persistently prods him to take another hack at it)..... but there's got to be a humorous anecdote for this thread about women who ask for directions... and men who won't.

My wife once said to me, "George, do you realize that every time I pose a question of you your first response is to always say 'No!'...??"

Without a moment's hesitation I immediately replied, "No it isn't!...."

markdoane · 09-05-2016, 02:17 PM

I have a Suburban furnace and have never had a problem with it. However, I recall hearing that Dinosaur Electronics makes good boards if you need to replace the ignitor board.

BessieB · 09-05-2016, 03:23 PM

Yes it is funny. I had to remind my husband as it is cooling off that we have to get that furnace working. But it would serve him right as he hits the hunting trail that he would have to freeze his hiney off since that was the main reason we bought the trailer, them cold frosty nights out in the boonies. I always have to do all the looking for info and such. But then again, I could just as well let him hitch up Tin Hut and head out with him forgetting that the furnace does not work.

BessieB · 09-05-2016, 03:25 PM

Quote:

Originally Posted by markdoane

I have a Suburban furnace and have never had a problem with it. However, I recall hearing that Dinosaur Electronics makes good boards if you need to replace the ignitor board.

The board is a Dinosaur and I have it bookmarked in case we need to order one.

BessieB · 09-05-2016, 03:48 PM

Quote:

Originally Posted by lewster

Look inside the 'plug'. You will see contacts on one side. Those must connect with the metal 'contacts' on the igniter board.

There should also be a slot in the board and corresponding plastic channel in the plug. Match them up and you're done.

Lew Farber

You are right, I went out and there is only one logical way to plug.

BessieB · 09-05-2016, 04:33 PM

Ordering the circuit board.....

rmkrum · 09-05-2016, 07:56 PM

Verify the sail switch, if it has one, is also working properly.

Sent from my pocket Internet using Airstream Forums

Mike1997 · 09-05-2016, 08:10 PM

My furnace was short cycling and would not stay lite first week I arrived in Montana last October. Not only was the board bad but the unit had never been used. PO only used electric heat in roof units. It was noisy at first but more it ran better it operated. Had no problems with it keeping galley and rear areas warm, but it would not heat up the front area very well. Had to run a small electric heater up there on cold nights...anything below 35 degrees.

Thank goodness do not need it in Florida this year!!

BessieB · 09-05-2016, 10:40 PM

Quote:

Originally Posted by rmkrum

Verify the sail switch, if it has one, is also working properly.

Sent from my pocket Internet using Airstream Forums

Pray tell....... what is a sail switch?

rmkrum · 09-05-2016, 10:57 PM

The sail switch looks like flat blade located where the blower can push air at it. When the blower is running properly the air flow moves the blade. It switches a switch that lets the electronics know the blower is moving air through the combustion chamber and that it's safe to ignite the burner. If the blade is stuck or out of position, the fan runs forever but the furnace does not light.

Sent from my pocket Internet using Airstream Forums

HiJoeSilver · 09-05-2016, 11:43 PM

Quote:

Originally Posted by BessieB

Pray tell....... what is a sail switch?

They call it a sail switch because it's a switch catching the air bowing by like a sail.

rmkrum described it about as good as I could have. Problem is its buried back by the fan and the furnace will probably have to come out to reach it.

This video might help identify it.

https://m.youtube.com/watch?v=sbYUBln-7Qs

Google this and you'll get some images "suburban propane furnace sail switch"

It's function is to keep the flame from igniting if there is no air blowing to remove the heat generated by the flame. This would cause heat to build up quickly and lead to a fire. Propane burns at 2800F in air so if nothing is drawing the heat away the metal heat exchanger in the furnace can get red hot pretty quickly.

BessieB · 09-07-2016, 08:48 AM

Interesting. Will wait for circuit board first before I send hubby out for further trouble shooting. He just LOVES this stuff!!!!

BAB · 09-07-2016, 05:20 PM

I'm sure models vary, but virtually all of the "things that can go wrong with a furnace" are accessible from the exterior panel. I had a bad board in my Classic. The guys at ODM (my dealer) had a testing outfit that they plugged into my board. It was "INOP" -- new boarding all goes well. BTW, the sail switch as well as the ignitor unit can be accessed almost as easily as the board itself.

BessieB · 09-25-2016, 11:08 AM

So the circuit board new did not solve problem. Hubby back from hunting trip that was wet, cold, muddy and snow also with his tent. So we tried out new circuit board and no ignition. He checked the striker contacts and lifted them a bit and cleaned them out, but a no go. So to get to the sail switch, I would have to pull out the furnace assembly? Is that behind the motor assembly that we had just replaced?
Hubby back out hunting. He waterproofed the bottom of his canvas tent. The snow settled and sagged the bottom which then puddled into the tent. Too bad, so sad, he should have worked on the trailer earlier this summer.

But he says he gets better access without the trailer to camp nearer his hunting grounds.