Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×

Go Back   Thor Forums > Thor Tech Forums > Maintenance and Repair
Click Here to Login
Thread Tools Display Modes
Old 04-15-2020, 03:11 PM   #1
Senior Member
Brand: Thor Motor Coach
State: Oklahoma
Posts: 107
THOR #8223
Furnace smoke (revisited)

We have a 2016 Thor Hurricane 34F. The original owner apparently never used the furnace (always in hot locations in the southwest), and when we first used it in 2018 we got the new furnace smoke I read about elsewhere here.

I followed advice given in another thread (, but I’m still getting a little bit of that smoke/haze. I’m using the RV as my “office” during our lockdown, and I inadvertently left the furnace on overnight (at about 60) so it cycled on and off for 12 hours. (I’ve noticed the burner cycles on and off off every so often—and I know it isn't 99 in here—so I assume its a safety feature to keep the parts from overheating.)

The RV wasn’t bad this morning, but still a bit smoky. So, I’m letting it run again for another 45 minutes. I’m wondering how many times I’ll have to do this. It seems other people have burned off the oils and manufacturing gunk once. Mine seems to be taking longer.

Thoughts or similar experience?



phoeg is offline   Reply With Quote
Old 04-15-2020, 08:41 PM   #2
Senior Member
Hooligan2's Avatar
Brand: Thor Motor Coach
Model: 2016 Siesta Sprinter 24ST
State: Florida
Posts: 559
THOR #2812
Smoke usually only the 1st time or two the furnace is run...
The furnace should run only the fan for a short period before the furnace lights....Burner should run until the temperature (thermostat) is satisfied and the burner should then stop and the fan continue until the unit cools and the fan will stop. (up to about a minute of fan only).. If there is a big temperature difference (RV is cold soaked) the burner may shutdown but relight again (thermostat cools) before the fan stops running.
It the furnace seems to always relight before the fan shuts down it may indicate an overheat condition where it is getting too hot, could be a kinked ducting or too many vents closed off.
U.S. Coast Guard retired- 1956-1985
Pensacola, Florida
2016 Siesta 24ST
1972 Moto Guzzi Eldorado
Hooligan2 is offline   Reply With Quote
Old 04-16-2020, 01:18 PM   #3
Senior Member
Brand: Thor Motor Coach
State: Oklahoma
Posts: 107
THOR #8223
Thanks for the response. The trouble here is that it all seems to run normally. I set the thermostat to 99 and let er rip. The fan starts, the burner lights and goes for a good long while, then the fan continues while the burner goes out for a short bit and then kicks back on. As long as the thermostat temp hasnt been reached, this will continue.

This morning there is still a bit of a haze inside the coach after I ran the furnace, but nothing like two days ago. (I still need to warm it up to work in here.) Im resigning myself to the fact that I may have to keep running it like this until whatever its burning off is all gone. Im definitely not having the success others have had with running it a long time once and burning it off.
phoeg is offline   Reply With Quote
Old 04-16-2020, 04:06 PM   #4
Senior Member
Brand: Thor Motor Coach
Model: 29h outlaw
State: New Jersey
Posts: 462
THOR #5248
Almost sounds like a critter made a home in your unit.
__________________ is offline   Reply With Quote
Old 04-16-2020, 04:59 PM   #5
Senior Member
Brand: Thor Motor Coach
Model: Hurricane 29M
State: Texas
Posts: 1,980
THOR #11781
I would have the furnace checked out by a qualified technician.
Lt Keefer
2018 Hurricane 29M
CHF, Saf-T-Plus, SumoSprings
Lt Keefer is offline   Reply With Quote
Old 04-30-2020, 01:03 PM   #6
Senior Member
Brand: Thor Motor Coach
State: Oklahoma
Posts: 107
THOR #8223
I thought I’d followed up here, but I see I forgot.

Anyway, since my previous response I’d forgotten to turn the furnace off a couple of nights that week, and so the furnace went on and off all night. (Made it comfortable in the morning when I came in to work, though.)

Anyway, the problem seems to have gone away after a couple nights of the furnace going. I had to start it this morning and it’s been fine.

Another mystery of RV ownership I guess.
phoeg is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Featured Campgrounds

Reviews provided by


This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.

All times are GMT. The time now is 08:09 PM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2