# Intermittend Furnace



## jfish21 (Feb 14, 2006)

I just went out this morning and started the furnace to start puttering inside, get things ready for the season. We just brought the new 29fbhs home a month ago and the furnace runs for 5-10 minutes 
and stops for 15 or so minutes before starting up again. Is this common with the carrier? the furnace in are old unit need not run this way. it took 5 hours to warnit up from 45 to 62.
any help would be great.


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## Scrib (Jun 28, 2005)

When it starts up again, can you hear it lighting (3 clicks)? Just wondering if it's only the fan that is intermittent.


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## Thor (Apr 7, 2004)

Welcome to Outbackers.com action

If I am reading you correctly, your furnance lights and runs for about 5-10min before shutting off.

It does actually light and produce heat from the ducts? Make sure you are on shore power. The furnance will shut off if your battery is too weak.

If there is no heat than your furnance did not light and you are just hearing the fan which is normal. Are you hearing clicks?

If you get heat - check your temp setting. Turn it right up and see how long your furnance runs. I know my trailer heats up very quickly.

Thor


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## jfish21 (Feb 14, 2006)

Thank for the welcome. 
it ligths. heats up have hot air
runs for a bit and shuts off completly for 15 or so minutes
and re ligths.
it is plug in to shore power


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## 7heaven (Jun 4, 2005)

I was wondering the same thing. If the trailer is plugged in to shore power, make sure the outlet hasn't tripped (if it's GFI) or tripped the breaker in the house.


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## HootBob (Apr 26, 2004)

Thor said:


> Welcome to Outbackers.com action
> 
> If you get heat - check your temp setting. Turn it right up and see how long your furnance runs. I know my trailer heats up very quickly.
> 
> ...


I would like thor suggested then see how long it runs for

Don


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## 2500Ram (Oct 30, 2005)

7heaven said:


> I was wondering the same thing. If the trailer is plugged in to shore power, make sure the outlet hasn't tripped (if it's GFI) or tripped the breaker in the house.
> [snapback]95273[/snapback]​


I second that. Check the breaker in the house. Ours used to trip all the time until I flipped the water heater breaker. An easy to see if the breaker has tripped is look at the clock on the microwave, do you have any lights. The microwave will not have a display on 12V battery.

Bill.


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## CamperAndy (Aug 26, 2004)

Guys he said it was working but was just short cycling.

I suspect a partially blocked outlet causing the furnace to shutdown on firebox high temperature.

You will need a mirror and flash light to inspect the ducts. Pull a vent and hold a mirror down in the duct, Shine a flash light on the mirror and you can see if the ducts are crushed and blocking the flow. The outlet duct could also be misaligned from the furnace to the main duct but that one is a lot harder to inspect.

I would also look at the inlet to make sure it is clear.

Good luck and let us know what you find.


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## ee4308 (Aug 23, 2005)

jfish21,

action Welcome to the site and congratulations on the new Outback. sunny Sounds like you have had some great advice on the furnace problem. Hope you were able to solve the problem. Post often.


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## hatcityhosehauler (Feb 13, 2004)

I found a misalignment with the ductwork in my '04 last spring. Here are some photo's and a brief description of how I fixed it.

Tim

Misaligned ductwork


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## Thor (Apr 7, 2004)

CamperAndy said:


> Guys he said it was working but was just short cycling.
> 
> I suspect a partially blocked outlet causing the furnace to shutdown on firebox high temperature.
> 
> ...


Great Point. The safety circuits will shut it down everytime.

Thor


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## GlenninTexas (Aug 11, 2004)

What is the temp set to? Could be the furnace is working fine, but the temp setting is at the lowest (63 degrees). Make sure when you change the temp you are positioned so that the sensor actually reads the signal from the remote. You should hear a beep each time you press the button, if not it didn't register, however the remote will show a higher temp setting. To verify, stand under the heater, pointing the remote directly at the receiver. push the temp down button, listening for the beep each time. Repeat until the remote shows 63 degrees. Then repeat pressing the temp up button, again listening for the beep each time, until the temp reads 72 or so. Then see how it works.

Regards, Glenn


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## jfish21 (Feb 14, 2006)

Think I figured it out after checking of blockages
I check the temp at the a/c unit where the thermostat is.
temp there is 1 - 2 deg above set temp when it shuts off
replaced register cover on duct below unit with a cover that can
be adjusted seems to do the job

thanks for all the ideas


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## Moosegut (Sep 24, 2005)

jfish21 said:


> Think I figured it out after checking of blockages
> I check the temp at the a/c unit where the thermostat is.
> temp there is 1 - 2 deg above set temp when it shuts off
> replaced register cover on duct below unit with a cover that can
> ...


Ahhh. Good suggestion. I was bemoaning the vent directly underneath the unit also and thinking about how the warm air is flowing directly up into the sensor. Diffusing it to the side will help alleviate the problem. Thanks.

Scott


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## hatcityhosehauler (Feb 13, 2004)

Didn't think of that as the 26RS doesn't have a vent right below the thermostat. That sure would explain alot. Glad it was a simple fix.

Tim


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## Oregon_Camper (Sep 13, 2004)

Surprised we haven't heard of this problem before..??


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## OutbackPM (Sep 14, 2005)

On our 26RS I have noticed the furnace kick on and off with a long cycle. It seems the thermostat is not that sensitive so it heats up a little too much and cools down a little too much also from the set temperature. I just assume that this was nornmal for the furnace. I think someone some where here put a new thermostat on which would probably improve the temperature swing.

Another thing to keep in mind as well is the furnace will shut down if the LPG gets low. The stove works OK but not the furnace. I found this out and turned to the new bottle and all was OK.

On the furnace outlets we changed for the adjustable type from lowes and can get more heat into the bunk house without burning up the opposite end.

What we use most is the Vornardo space heater. Its digitaly controlled so does not just turn on and off but regulates the heat as it approches the temp setting. Its very quiet and can circulate air to the bunk house so saves your LPG but we do use the furnace to warm up the Outback when we first get in because it has way more heating capacity. If it were less than freezing outside then you would need it more to keep the underside warm enough to prevent water line freeze up.

David


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## jfish21 (Feb 14, 2006)

the wife and kids spent most of the afternoon yesterday out in the OB
and i spent a couple of hours the other evining and today in it and the adjustable 
cover did to the trick also helps with a more even heat thru out the unit.
Now Im goning to change the one in bunk room.









jerry


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## 2500Ram (Oct 30, 2005)

Jerry, I read your fix and the new floor registers, you mentioned ducting but was there a problem with the ducting or just new floor registers the fix.

Either way glad it's working now.

Thanks

Bill.


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## jfish21 (Feb 14, 2006)

just the register covers seams to be 50% in bunk room 40% in living area right brlow the sensor and 10% in front bedroom and bath.
changed the cover to defuss the heat away from sensor. now there is even heat from about 3' high to the ceiling


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## GoVols (Oct 7, 2005)

Interesting thread. After running the furnace in our new 26RS to burn off the new smell, I noticed a very similar problem.

The first night I ran it I set the thermostat to 70 degrees and left it to run overnight. Before I turned it on, I placed two thermometers in the camper, one on the dinette and one in the bunk room on top of the wardrobe.

The morning after the first overnight, I went in the camper and I was fairly pleased with the outcome: the dinette thermometer was at 69 and the bunk room thermometer was 72.

The second evening though there were problems. When I turned the furnace on the temp inside the camper was 65. The furnace lit and warm air was coming out. After about 5-10 minutes, the furnace cut off but had not achieved the 70 degrees like the night before. I bumped up the temp to 72, and again the furnace ran for a little while but shut off before getting close to the temp. I bumped it to 75 and it seemed to run OK, but was getting too hot in the camper. I reset it to 72 degrees for the overnight.

The next morning I went in and the temp inside the camper was 64 but the furnace was not running. Any ideas?


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## PDX_Doug (Nov 16, 2004)

I must be dense this morning, but I don't get what the problem is?







Furnaces are supposed to turn on and off periodicaly. That's what thermostats are for.









If you are comparing it to the furnace in your old trailer that took five hours to heat the trailer, all I can say is, your old trailer had a crappy furnace!

The basic question is: Is the furnace heating up the trailer? If it is, don't worry about it.

As far as having a vent directly below the thermostat, it is hard to imagine that being much of a problem. It does not take much movement in the trailer to get the air all stirred up anyway. Maybe at night.

Just my sleepy two cents...

Happy Trails,
Doug


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## GoVols (Oct 7, 2005)

PDX_Doug said:


> I must be dense this morning, but I don't get what the problem is?
> 
> 
> 
> ...


In my situation Doug, no, it is not heating up the camper. It will run for a few minutes but cut itself off before achieving the preset temperature. To me, if I have the thermostat set at 72, but the next morning the inside temperature is 64, it's not working.


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## PDX_Doug (Nov 16, 2004)

GoVols said:


> In my situation Doug, no, it is not heating up the camper. It will run for a few minutes but cut itself off before achieving the preset temperature. To me, if I have the thermostat set at 72, but the next morning the inside temperature is 64, it's not working.
> [snapback]99303[/snapback]​


Vols,

Is the furnace heating at all? Do you get hot air out of the outside exhaust vent when it is running?.

If the answer to those questions is yes, then I would suspect you have a bad control board in the Carrier.

Happy Trails,
Doug


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## GoVols (Oct 7, 2005)

PDX_Doug said:


> GoVols said:
> 
> 
> > In my situation Doug, no, it is not heating up the camper.Â It will run for a few minutes but cut itself off before achieving the preset temperature.Â To me, if I have the thermostat set at 72, but the next morning the inside temperature is 64, it's not working.
> ...


Yes, hot air comes out of the registers. I am going to test it some more, likely Saturday night since the temps are supposed to dip. After the first night's successful test, it has not stayed on long enough to move the temp up (within reason) close to the setting on the remote.


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## PDX_Doug (Nov 16, 2004)

Vols,

I have been thinking about this, and I don't have the remote in front of me, but isn't there a Timed mode for the furnace? It is so that you can set the furnace to run for a set period of time, say when you go to bed at night, and then shut off until you restart it. If memory serves, the delay is also adjustable.

If that is the case, I wonder if your inadvertently got put into that mode, and now it is just doing what it has been told?

I may be way off base here, but there is something...

Happy Trails,
Doug


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## GoVols (Oct 7, 2005)

PDX_Doug said:


> Vols,
> 
> I have been thinking about this, and I don't have the remote in front of me, but isn't there a Timed mode for the furnace? It is so that you can set the furnace to run for a set period of time, say when you go to bed at night, and then shut off until you restart it. If memory serves, the delay is also adjustable.
> 
> ...


Let's hope that is it, but I'm doubtful. Does the timer display anything on the remote's screen? I clearly recall the only thing showing on the remote was an arrow to "Furnace" and an arrow to "auto" (fan speed).


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## PDX_Doug (Nov 16, 2004)

Vol,

I just checked Ghosty's link to the Carrier Owners Guide (from another thread), and at the end in the troubleshooting section, the 'Timer Off' function is given as one of the two reasons the unit will shut down (the other being the correct temperature has been reached).

Check it out here. Look on page 18.


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## PDX_Doug (Nov 16, 2004)

GoVols said:


> Let's hope that is it, but I'm doubtful. Does the timer display anything on the remote's screen? I clearly recall the only thing showing on the remote was an arrow to "Furnace" and an arrow to "auto" (fan speed).
> [snapback]99366[/snapback]​


Vols,

Also in the manual (page 6), you will see a depiction of the remote display. The timer modes are indicated at the top of the display.

HANDY NOTE #349:
Always bear in mind that the communication between the remote and the HVAC unit is one way (from the remote to the Carrier). The data displayed on the remote display is an indication of what the remote has told the main unit to do, but does not reflect what commands the main unit has actually received.

It is very easy to get the two out of sync. Each time you press a button on the remote you must hear a beep from the main unit acknowledging receipt of the command. If you did not hear the beep, the remote will now be displaying a condition that does not actualy exist. Cover the IR transmitter on the end of the remote, and return it to the previous setting, before trying again.

Good luck!

Happy Trails,
Doug


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## tdvffjohn (Mar 10, 2005)

So Doug, that means that a HVAC unit is a lot like a guy. Just because he was given an order, does not mean he heard it. If she does not hear a grunt, assume message was not recieved









John


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## PDX_Doug (Nov 16, 2004)

ROTFLMAO!









Yeah John... Sometimes even if she does hear a grunt!...

Happy Trails,
Doug


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## wolfwood (Sep 19, 2005)

tdvffjohn said:


> So Doug, that means that a HVAC unit is a lot like a guy. Just because he was given an order, does not mean he heard it. If she does not hear a grunt, assume message was not recieved
> 
> 
> 
> ...


...and even if the grunt is heard, it is necessary to comfirm the message "the unit" received as it may be out of sync with the sender. And here, I thought all this TT stuff was gonna be confusing and tough to learn.







Heck, "built by men - acts like men". Ladies - we've got this bit under control! 'nuff said


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