New Cougar - Furnace wont heat above 60

[nebmike]

Just took delivery of a brand new Cougar 33SAB travel trailer. For some reason the furnace will not heat the inside of the unit to more than about 58-60 degrees... its been about 25 degrees overnight.

This is my third camper and I've always been able to heat to 70+ at temps well below 25 outside.

Fan seems to be pushing an appropriate amount of air, it just seems like the air coming out isn't as warm as I'm used to.

Also, it seems as though every few minutes it'll blow cooler air for a while and then go back to somewhat warmer.

Help? Really not wanting to wait weeks for a warranty appointment. 😕

Thanks in advance!

[Old-Biscuit]

Chris Bryant wrote:

nebmike wrote:
One final question for you fine folks... during all of this I noticed that the rear panel on my furnace (where the three main ducts come off of) is a bit crooked and there is quite a bit of heat escaping around the edges of it. Would it be worth my time to tape it with some aluminum tape or just leave it be?

Seal it up. That hot air will be drawn back in to the return, causing overheating.

That was probably original issue with 'limiting'

Addition of extra duct allowed more discharge flow that was most likely blowing out around gap at a higher rate/temp.
Sealing that leak would have probably cured initial issue w/o new limit switch, new additional duct and new registers.

[time2roll]

Any leaks not into the living space can be taped up.
If you are warm in 15 minutes I can't imagine the furnace is undersized.
I have always thought if RVs were better built we would not need such large cooling and heating equipment.

[dougrainer]

The fact is, you have an undersized Furnace. NOTHING changes that. Doug

[Chris_Bryant]

nebmike wrote:
One final question for you fine folks... during all of this I noticed that the rear panel on my furnace (where the three main ducts come off of) is a bit crooked and there is quite a bit of heat escaping around the edges of it. Would it be worth my time to tape it with some aluminum tape or just leave it be?

Seal it up. That hot air will be drawn back in to the return, causing overheating.

[nebmike]

One final question for you fine folks... during all of this I noticed that the rear panel on my furnace (where the three main ducts come off of) is a bit crooked and there is quite a bit of heat escaping around the edges of it. Would it be worth my time to tape it with some aluminum tape or just leave it be?

[nebmike]

Thanks for all the great advice and suggestions, everyone!!!

I picked up a limit switch and swapped it out. Also changed all the floor registers to a design that is less restrictive than the originals, and then plumbed in an additional duct off of the furnace (pics). The furnace sits directly behind the panel where I installed the white fixture. I drilled the door and installed a vent so that they line up when the door is closed.

Works perfectly and it got up to 72 degrees within about 15 minutes or so (that's just where I had the thermostat set - I'm sure I could go warmer if I wanted). Its 32 outside right now. This morning when it was 35, I couldn't get it past about 60-62 even after it had literally been running non-stop all night long.

Y'all are awesome! Now, off to pack for a short maiden voyage this weekend...

[wasatchmtnatvr]

If I recall old school rule of thumb was 1000 btu per foot rv foot. This was way before slides though.

[time2roll]

nebmike wrote:
Also, it seems as though every few minutes it'll blow cooler air for a while and then go back to somewhat warmer.

This sounds like the burner is cycling probably due to inadequate airflow causing the high limit switch to open for the heat exchanger to cool. Listen very carefully and you should hear when the burner kicks back on. Harder to tell as it shuts down. Cycle maybe every 1 or 2 minutes.

My main duct in the floor was collapsed as built new. Did my best to prop it open but the solution was to add two more ducts. I assume yours is different but similar issue.

[dougrainer]

I went thru this last year with a Cruiser Travel trailer. The customer had the exact same problem on a 28 foot with 1 slide. They installed a 20k Suburban. I do not have the formula at home, but Suburban gave me the number you use to take the Square Foot of the trailer and the number you multiply with to get the BTU size furnace. I had to remove the too small Furnace and `since the larger would not fit in same exact spot I had to install a 30k and cut a hole in the side of the trailer where the old furnace was. Cruiser also denied and stated that that furnace was the correct size, but after I gave then Suburbans figures they paid for the modification. If you call Suburban they will give you that figure to use. The 30k was just at the limit for this size trailer. I can guarantee you, your furnace is WAY undersized for your size trailer. Doug

[SkiingSixPack]

Are there any fault codes for these furnaces, like on home models?

I know my high limit switch code on my home furnace by heart now.... It wasn't until I went through 2 of them that I found the culprit ... 2 filters shoved up inside the air return from the sheet-rockers when the house was built. Hasn't blown another limit switch yet. It isn't always the warm air registers that are the problem.

Hope you find the reason IF it does turn out to be the high limit switch. Something constricting airflow is the most likely, as others have pointed out.

[nebmike]

Old-Biscuit wrote:
Do you get roughly same air flow out ot all the ducts?

Crushed flex ducting?

Anything surrounding furnace that would restrict air return flow?

Same air flow from all ducts - and its strong flow compared to my previous two campers. There is absolutely nothing obstructing airflow around the furnace itself. I even took all of the registers off of the vents (just to maximize air flow) and removed both access panels to the compartment where the furnace is... no change in the problem.

I'm on my way to pick up a limit switch right now, to at least eliminate that as a potential problem even though the camper is brand new. Fingers crossed -- I really wanted to go boondocking this weekend!!!

[Old-Biscuit]

Do you get roughly same air flow out ot all the ducts?

Crushed flex ducting?

Anything surrounding furnace that would restrict air return flow?

You are hitting the high limit so flame goes out then back on then out (repeat) and fan continues to run,,,,,,so something is restricting the amount of air flow (return and/or discharge)

20K BTU furnace is small for that size TT BUT it would eventually get to t-stat set point over time but can't due to high limit switch opening/closing.

Restricted air flow -----somewhere

[MEXICOWANDERER]

Call the dealer.

Invite them to spend the night in your rig.

When they go inside, barricade the door.

That'll learn 'em.

Seriously...

Does the state of Colorado have a Department of Consumer Affairs?

Do the people at "Cougar" ¿espeak English?

[Chris_Bryant]

That is way too small for a 37', 3 slide rig- 2 of them would work, but no way will one be enough in anything below slightly chilly.
That said- it does sound like it is hitting the limit switch, which a properly working, properly installed furnace will not do.