Wednesday, November 9, 2016

How to Use the Furnace

There are a lot of things that those who have had an RV for awhile just do automatically, but for a first time RV owner there are many things that a good step by step understanding of will help a great deal. I have had several readers email and ask about some of these things and I will try to do some more articles on some of the basics. Since we are now in November and there may still be some who are not ready to set their RV aside for the winter quite yet, I will start with the FURNACE. (If you have a new Roadtrek and don't have a furnace for heat, this does not apply to you.)

The furnace in the Roadtrek and most RVs runs on both PROPANE AND BATTERY. The propane is the fuel used to make the heat. The battery is needed to:

-  Ignite the propane
- Run the fan to move the heat out of the furnace and into the RV

I have an article already about propane and you can go there to learn from this two part article about how to turn on your propane and also what to do when you first turn it on to make sure there is propane gas in all of the gas pipes.

So to use your furnace -

TURN YOUR PROPANE ON - Get it into all pipes (see article link above).


The furnace switch is on a control panel. Mine is located at the rear of the cabin on the passenger side on the wall above the bed. I have a mechanical switch with slide switches. The newer Roadtreks have a digital switch with a digital thermostat display. Both do the same functions.

This is what mine looks like. If you have an older Roadtrek yours should look similar.

Here is what the digital switch looks like -






SLIDE THE SWITCH (or push buttons on the digital version) TO FURNACE

What should happen now is you will hear the blower fan inside the furnace turn on. It will be blowing cold air - that is what it is supposed to do right now. After a short time you will hear a CLICK. That CLICK is the battery run ignition lighting the propane.

IF THE FURNACE KEEPS CLICKING it means that the propane did not light. IT WILL ATTEMPT TO LIGHT SEVERAL MORE TIMES. If it does not light turn off the Furnace switch on the wall and check that all setting are as described above, that there is PROPANE in the tank, and it has been run through all the lines as that link above tells you how to do. Once checked, turn on the Furnace switch again.


There will be no more clicks and in a few minutes when you put your hand in front of the furnace vent inside there will be heat coming out and not cold air.

Your furnace is now in operation!

Set your thermostat lower if it gets too warm or higher if it is not warm enough. What will happen is with the settings on AUTO the furnace will turn off when it reaches the temperature set and turn back on when the temperature gets colder again. This cycling on and off is NORMAL.




The first time that a new furnace is turned on, the furnace flame will burn off any packing oil that the furnace parts were coated with. This will result in a lot of smoke and a sharp burning smell. This IS NORMAL!  Once the smoke that this results in clears and is out the window or the fan, you can push the button to stop the smoke detector and it will not go off again. If it does, there is still more to burn off and exhaust out.


THIS WILL OFTEN ALSO HAPPEN THE FIRST TIME THE FURNACE IS TURNED ON FOR A NEW SEASON. Dust, etc. collects inside the furnace and this too burns off when the furnace is ignited and will set off the smoke detector. IF it does, just do the same as above to stop it.


You would think that this is just as simple as moving the switch to OFF - and it IS, BUT...

When you turn the furnace off the flame will go out BUT the furnace fan will run for several minutes to cool off the inside of the furnace. THIS IS NORMAL! But it is very disconcerting. It troubles me when I first use the furnace after awhile and I never have gotten used to this. You hear it keep running. It will stop. Even though, if you are like me, you don't think it will stop - it will stop.

The furnace is VENTED outside. Here is a photo of the vent usually located on a Roadtrek just past the driver's door on the side of the van:

Always keep this vent CLEAR! If you are in the RV in the winter and it has snowed. Clear this off of snow if you are going to put on the furnace. If there has been an ice storm, clear all of the openings of this vent of ice. If you do not DO NOT TURN ON THE FURNACE. There are also special screens made and sold just for this vent to keep bugs out. Bugs can build nests or webs and cause all types of problems for the furnace.

That is it! You now are an expert in using your RV furnace!



  1. Robert, you are a Godsend! Thank you again for all the knowledge you've shared with us. It's like you know me and my husband, with all your encouraging words, too! (-;

  2. Do I need a new battery? I replaced my thermostat, but after my heater runs through the first cycle and clicks off, it doesn’t click back on during the night. I’m thinking my battery has gone dead…. no choose to allow it to click on again?!

  3. I am not sure why you would jump to the cause of this being your battery. There are so many questions to answer first. When you have the battery switch on - what is the battery voltage level on your meter? Have you checked the battery voltage with a multi-meter? When on battery does everything else work - does the water pump, pump? Does the hot water tank heat water? Do the ceiling lights turn on? Does all of this stay working? None of this is possible if your battery is dead! Possible problems - full propane tank? Igniter in furnace is not working to ignite the propane? When you turned on the propane did you test to see if it had filled all of the propane pipes by first lighting both burners of the stove to see that here is propane going to the last appliance connected to propane pipes (which is the stove)? Have bugs built a nest in the furnace vent going to the outside of the van (two vent holes one above the other on a chrome rectangular plate? Does the furnace need to be serviced? AND MOST IMPORTANT - have you tried to run the furnace while plugged in - which eliminates battery charge all together? We can discuss this further by email if you wish - but you need the answers to all of these questions before we can troubleshoot this further. Contact link is on the right column of this page. If you email I need to know the year and model of your Roadtrek in the email.

    1. My burners on the stove will light, hot water heater working. Fan on furnace working but will not ignite. 2008 Roadtrek Popular 210

    2. CathyinDenver - It could be a few things. Battery is good if the furnace fan is running and that also means the fuse is OK. There could be a clog in the furnace vents outside - last photo in this article is the furnace vents. Bugs can make a nest and clog the vent.If the vent is clogged the furnace is not going to light. Look in first with a bright flashlight and see if you see anything blocking the opening inside - both holes. To better see you would have to open the screws (they are Robertson square head screws like every other screw RT uses. Then you can get a better look. IF that is clear - the next thing would be to see if the propane pipe in the furnace that faces the igniter is clogged the same way. This is not so easy because unlike the hot water heater with all this accessible from outside, the furnace is all inside and in the bottom of an enclosed base of a cabinet. The furnace front has to come off. I have never gone that far - so I can't say what you will see and how easy it is to get to the ignition location of the furnace. The other thing it could be is the "thermocouple" could need replacing. These burn out over time. What to do depends on how mechanically inclined you are and what you are willing to do. My feeling is that anything connected to propane should be done by a pro. Do none of these with the propane still on - and when you turn it off, have the stove lit - this will burn off any remaining propane in the pipes. If that is not done you have pipes full of propane where you are working and inspecting. If you hear clicking while the furnace is trying to light, that is the igniter in the furnace trying to light the propane. It will try for a while. At that point after a couple of minutes of it trying to light, turn it off. The fan will still run for a short while - which is how the furnace is set up - the fan keeps going to cool the furnace down - even if it can't ignite. The easy fix is if you find the outside vent is clogged.

  4. We recently bought a 1993 Chev Roadtrek. Everything seems to work except I can't figure out the furnace. The thermostat is different from the one pictured and it doesn't light. The stove works fine so I know the LP is flowing. How do you light the furnace? Can you do it manually?

    1. There is no way to light the furnace manually. It is an electronic ignition. There are differences from Roadtreks in the early 90's to Roadtreks in the 2000's but the Dometic furnace should be basically the same.It is possible that the furnace has an on/off switch that is not part of the thermostat - thought the thermostat in the Roadtreks before Roadtrek started to use the Cool Cat A/C unit should just be for the furnace - as the A/C Roadtrek used then was more like a home A/C with its own controls on the A/C itself. There is a Facebook group just for Vintage Roadtreks -and the name of has "Vintage Roadtreks" in its title. That would be the best place to get the answer to how to get your furnace running. From your description I would say that there is no problem with the furnace itself, as it seems you have not found the switch to turn it on. If it was trying to turn on you would be hearing clicks of the igniter in the furnace trying to ignite the propane. But if nothing happens at all - the switch has to be located. I don't want to guess - but if I was to guess - what happens when you turn the thermostat up to a high temperature - like 80? If the thermostat turns it on that might do it - bring it to a temperature definitely higher than the interior of the van. Best thing - get on the Vintage RT group on Facebook as there will be members with exactly the same RT has you have.

    2. Did you check the little lever underneath the thermostat? It is well hidden but on the bottom left on some of the older thermostats there is a little on/off lever. To the left for Off, to the right for On.

    3. Derek - The analog thermostat that I have in my 2011 - pictured in the article has an OFF setting on the slide that picks what function you want to turn on. This may be different on the thermostat used in 1993. Over the years Roadtrek made a lot of changes in the equipment they installed.

  5. Hello, It got complicated to give my name but my name is Rebecca :)

    Where is the battery switch? I assumed it is always on, but assuming is not a good plan haha. We just got this Roadtrek 190 Versatile from son/stepson and it came with no manual so it ends up with a lot of searching since it is so old (1992) and we can 't find a manual. Thanks for your posts!

    1. Here is the manual for your 1992 and it covers all models from that year. Section F,5 talks about the coach battery (or auxiliary battery is they put it). The implication is that there is no battery switch - which is not a good thing. Roadtrek manuals were rarely very good - and this one has no photographs as later ones at least have. There is a group on Facebook for Vintage Roadtreks and I suggest you get on that group as there will definitely be other 1992 190 owners.