heater problem, fan kicks on exhaust feels hot...

Pulln · 01-02-2015, 05:17 AM

Well not bragging but it has been a year since I have had to use the heater. Last time we used it it was blowing hot and strong. I set the heat on this morning and it comes on for a about a minute and then shuts off.

The exhaust vent outside feels like hot air is coming out but inside the air from the floor vents is not. Fuse panel looks fine and we have plenty of gas, I am assuming it is a gas furnace. I should know more about the heater but in my defense I do live in SW Florida.

Appreciate the tech tips!

Happy New Year.

**JRTJH** · 01-02-2015, 07:17 AM

Since the furnace hasn't been operated for almost a year, you could have a blockage in the intake or exhaust vent on the outside. Dirt daubers and spiders have a habit of liking places like that to build their "temporary living quarters"

If the intake (probably) or exhaust (less probable) were partly blocked, you wouldn't get enough air movement for combustion and the firebox could overheat shutting down the furnace.

Use a flashlight to check for any obstructions. A bottle brush will remove most spider webs and even some dauber nests. If you're lucky, that's all you'll have to do. Otherwise, the troubleshooting guide in your owner's manual has several other options.

I'd first look for the simple things. No use for a long time, living in Florida, increased insect activity, blocked vent.....

Good Luck

Lee · 01-02-2015, 07:47 AM

John has given you some sound advice. Only thing I can add is to ask: When you turn the Heat on, the blower should start up and run for about a minute. Then the ignitor should fire (Tick, tick, tick) and ignite the gas. Then you should hear the "Woosh" of the burner.

Are you hearing the "Ticks" and the "Woosh"?

If you get the "ticks" and no "woosh" as John suggests something is preventing the gas from flowing.

If you get the ticks and the woosh and thhen it shuts down I would suggest that the Thermocoupler is defective.

Good luck and let us know what you find.

Pulln · 01-02-2015, 08:21 AM

Quote:

Originally Posted by JRTJH

Since the furnace hasn't been operated for almost a year, you could have a blockage in the intake or exhaust vent on the outside. Dirt daubers and spiders have a habit of liking places like that to build their "temporary living quarters"

If the intake (probably) or exhaust (less probable) were partly blocked, you wouldn't get enough air movement for combustion and the firebox could overheat shutting down the furnace.

Use a flashlight to check for any obstructions. A bottle brush will remove most spider webs and even some dauber nests. If you're lucky, that's all you'll have to do. Otherwise, the troubleshooting guide in your owner's manual has several other options.

I'd first look for the simple things. No use for a long time, living in Florida, increased insect activity, blocked vent.....

Good Luck

I did find a dirt dobbers nest in there but wasn't able to get the furnace to stay on after clearing it out. That joker was way back there but thankfully I had a coat hanger on hand.

Pulln · 01-02-2015, 08:24 AM

Quote:

Originally Posted by Lee

John has given you some sound advice. Only thing I can add is to ask: When you turn the Heat on, the blower should start up and run for about a minute. Then the ignitor should fire (Tick, tick, tick) and ignite the gas. Then you should hear the "Woosh" of the burner.

Are you hearing the "Ticks" and the "Woosh"?

If you get the "ticks" and no "woosh" as John suggests something is preventing the gas from flowing.

If you get the ticks and the woosh and thhen it shuts down I would suggest that the Thermocoupler is defective.

Good luck and let us know what you find.

I do hear the ticks and the whoosh. I also verified that there is heat being vented from the exhaust during the 3 lighting cycles.

I haven't been able to verify the model of the furnace yet but I did see a red light blinking 3 times on the top of the furnace.

crash · 01-02-2015, 08:40 AM

We had the same thing happen last year and it was the thermocoupler that went bad.

Pulln · 01-02-2015, 08:54 AM

Am I tracking the thermocouple operation right. So the the thermocouple would look for heat from the furnace and if it registers it would allow the furnace to stay lit. I can feel heat from the furnace lighting up during the 3 start cycles so if the thermocouple doesn't read right then it shuts off the furnace, is that about right?

**JRTJH** · 01-02-2015, 09:05 AM

The Atwood Furnace Flashing Trouble Codes information:

Fault ---- LED Indication

Internal Circuit Board fault ---- Steady on, no flashing

Limit switch/Airflow problems ---- 1 flash with 3-second pause

Flame Sense fault ---- 2 flashes with 3-second pause

Ignition Lockout Fault ---- 3 flashes with 3-second pause

Pulln · 01-02-2015, 09:16 AM

Quote:

Originally Posted by JRTJH

The Atwood Furnace Flashing Trouble Codes information:

Fault ---- LED Indication

Internal Circuit Board fault ---- Steady on, no flashing

Limit switch/Airflow problems ---- 1 flash with 3-second pause

Flame Sense fault ---- 2 flashes with 3-second pause

Ignition Lockout Fault ---- 3 flashes with 3-second pause

Thank you John.

scott24 · 01-04-2015, 06:55 AM

Your flame sensor could be dirty and not sensing flame. If that happens, the burner shuts down after about 5 seconds. A thermocouple is found on standing pilot burners.....not automatic ignition equipment.

Pulln · 01-04-2015, 02:44 PM

I think I need to get a schematic so I can figure out where these parts are when I get the cover apart.

Thankfully the weather was brilliant for the remainder of the weekend and we didn't need the heat after we found out the hard way it is broken. I may just have a tech come out and take care of it for us.

**chuckster57** · 01-04-2015, 05:57 PM

With brand and model # in hand, schematics should be readily available on the manufacturers website.

Pulln · 01-04-2015, 06:38 PM

Quote:

Originally Posted by chuckster57

With brand and model # in hand, schematics should be readily available on the manufacturers website.

Thats what I am hoping. We just returned home and hoping I can empty the basement and start removing panels. I didn't see any labels on the the most accessible parts while snooping around in there.

The gas is definitely getting there though as I can hear and feel it at the exhaust port.

**sourdough** · 01-07-2015, 11:26 AM

I am experiencing a problem exactly like this sporadically. It's in the shop now for them to diagnose (if it will fail) because I want the warranty to pay for it vs me.

As John pointed out you are experiencing the ignition lockout fault. That is caused by the sensor not sensing enough fuel flow to run the furnace. My conversations with Atwood and the shop would indicate a couple of things; Mark at Atwood suggested replacing the ignitor which is responsible for that function. Said it takes about 5 minutes to do. It could be a possible malfunction of the control board...but probably not. Another issue is your LP supply. Are the tanks full? Have you switched the valve between the tanks from one to the other? One resolution I found was that the regulator, when quickly switched between tanks, would not fully pressurize the fuel to the furnace. The suggested resolution was to very slowly rotate the selector from one tank to the other then back...slowly. I was advised by the tech at the dealership that this could be an issue. You might try that. They also said the positioning of the furnace sensor might need adjusting...I did not dig into that.

If it is doing it consistently (3 attempts then shutting down) and you can't get it to start you have to let the control board reset. I did it by pulling the power lead for the control board from the pin. Atwood said you can do it by turning the thermostat off and letting it turn the board off. It will then attempt to ignite 3 more times. They also said there is a reset button on the furnace but I did not look for it.

A lot of stuff I know but I've been neck deep with this for a week or two. I don't think my situation is dire, and could very well be the LP valve issue since I replaced one of the LP tanks the day before my last failure, but yours could be ? I do know the first time ours failed we were on the road and I had no idea what was going on so just ran an electric heater for the last night on the return trip home. Hope some of this might help and good luck on getting it going.

Pulln · 01-07-2015, 11:32 AM

Quote:

Originally Posted by sourdough

I am experiencing a problem exactly like this sporadically. It's in the shop now for them to diagnose (if it will fail) because I want the warranty to pay for it vs me.

As John pointed out you are experiencing the ignition lockout fault. That is caused by the sensor not sensing enough fuel flow to run the furnace. My conversations with Atwood and the shop would indicate a couple of things; Mark at Atwood suggested replacing the ignitor which is responsible for that function. Said it takes about 5 minutes to do. It could be a possible malfunction of the control board...but probably not. Another issue is your LP supply. Are the tanks full? Have you switched the valve between the tanks from one to the other? One resolution I found was that the regulator, when quickly switched between tanks, would not fully pressurize the fuel to the furnace. The suggested resolution was to very slowly rotate the selector from one tank to the other then back...slowly. I was advised by the tech at the dealership that this could be an issue. You might try that. They also said the positioning of the furnace sensor might need adjusting...I did not dig into that.

If it is doing it consistently (3 attempts then shutting down) and you can't get it to start you have to let the control board reset. I did it by pulling the power lead for the control board from the pin. Atwood said you can do it by turning the thermostat off and letting it turn the board off. It will then attempt to ignite 3 more times. They also said there is a reset button on the furnace but I did not look for it.

A lot of stuff I know but I've been neck deep with this for a week or two. I don't think my situation is dire, and could very well be the LP valve issue since I replaced one of the LP tanks the day before my last failure, but yours could be ? I do know the first time ours failed we were on the road and I had no idea what was going on so just ran an electric heater for the last night on the return trip home. Hope some of this might help and good luck on getting it going.

Great info for sure. I'll head out to my storage facility on Saturday and see if I can put some of this knowledge to good use. Thank you!

**JRTJH** · 03-21-2015, 09:43 AM

Quote:

Originally Posted by Pulln

Great info for sure. I'll head out to my storage facility on Saturday and see if I can put some of this knowledge to good use. Thank you!

Noah,

Did you ever figure out your furnace issue?

Pulln · 03-21-2015, 11:11 AM

Quote:

Originally Posted by JRTJH

Noah,

Did you ever figure out your furnace issue?

Very timely follow up. I just picked the camper up an hour ago from the tech that takes care of some of maintenance and repair needs.

So he ended up replacing the furnace board. He said there was a bur/scorch mark on it. He said he also found some bugs closer to the furnace exhaust as well.