RV Doctor – Is It Safe To Run the Furnance Off the Generator While Traveling?

author image

August 6, 2009

Dear RV Doc,
I have heard of running the roof air conditioner off the generator while traveling. Is it safe to run the furnace off the generator while traveling? We travel to Florida every March and sometimes the first morning is quite cold, even after preheating the coach for several hours before leaving. The dash heater could not keep up with the heat loss while traveling. Riding in an over-sized icebox isn’t much fun.
– Bill Lemke, (South Wales, NY)


Gary BunzerBill, I think I’m a little confused by your question. Typically a stand-alone RV furnace is powered by 12-volt DC, whereby the fan, thermostat and internal components all run off the auxiliary battery. There’s no reason to run the generator at all.

But to run down the road with the LP on? You really want me to open a can of worms, huh? There are two schools of thought concerning running down the road with the LP on; one is that it is safe and permissible IF you are absolutely sure the LP system is set up properly and totally leak-free. However there may be some restrictions in some tunnels, on some turnpikes, ferry boats, certain roads and bridges. It may still be illegal to run with the LP on, so you must check your route and determine if there are any restrictions in the areas you will be driving. But as long as the RV has been maintained properly; all components cleaned and serviced regularly, the LP system inspected and adjusted properly, the entire system checked for leaks, etc., then as long as there are no local restrictions, go for it. After all, it IS a self-contained RV! Right?

The second school of thought is, why? Unless you are traveling in very cold weather and it stays below freezing inside your rig as you drive, it’s doubtful it will overtax the furnace to wait until you stop for the night. But if the dash heater just isn’t cutting it, and you are physically uncomfortable, perhaps running it in the morning as you drive will be sufficient. But remember this is only if you are satisfied every LP component is maintained properly and you can guarantee there are no leaks anywhere in the system. The problem is, many RVers are not aware of the many facets of RV safety as it relates to RV preventive maintenance. So if I’m driving my RV down the road, I’ll probably have my LP on and the refrigerator fired up, but as I pass other RVers, I’m hoping they do not!

(Please feel free to comment, however, please also note that due to the volume of communications I receive from multiple channels I cannot guarantee a personal response in every instance. However, questions of an overall general interest may be considered and published in an upcoming RV Doctor column.)

Leave a Reply


  1. Joe Kentrus

    Regarding the refrigerator on LP while driving, I have used the blue ice packs, frozen the night before, and placed in the refrigerator while traveling, works just fine.
    I’ve traveled 12 hours in the warmest areas, and found the contents to be just as cold as when I left. Just don’t keep opening the door. The freezer compartment still had ice cubes, no water. Cheap and safe. If necessary, the next time you gas up, buy a bag of ice, it’s cheaper than propane, and makes your drinks cold.

  2. Guys & Gals:
    Don’t forget the pilot light on your refer will be lit when you pull in to a fueling station.

    To me this is the biggest hazard to leaving the LP on while traveling.

    A security camera caught the results of this flame/gasoline combination in Arizona. Not a pretty site – the young lad near the fire/explosion had major burns, 80% of his body.

    Happy Camping
    Fred b. rv101byfred.com

  3. Darthvagrant

    I had trouble heating my (admittedly poorly built) Class A when moving. There was obviously much cold air coming from SOMEWWHERE. I fashioned a thin luan covering over the side door with a large squirrel-cage blower blowing OUT. Wow! A whole lot of air coming through MANY openings and crevices was immediately evident in the firewall / front area. A couple of cans of expanding foam and some foam rubber “stuffing” closed them. A few voids and holes in other areas became even more evident as I closed those I could find.
    Worked for me! Pull a slight vacuum on the coach. Crawl around under the dash, etc., and close the air leaks that then become quite evident. Bonus: The dash air works more effectively too.

  4. Mark Skotek

    I added extra heaters connected to the engine that I got from school busses in the scrap yard. When placed in the living quarters with a seperate valve and switch it worked well. I did run with the gas on all the time to keep the referigator operating and never had any problems.

  5. Mark

    What if you have a heat pump in your rig, as I do? I assume it would be no different than running it to cool off or heat up.

  6. Thomas Becher

    We leave home in Jan with a fifth wheel and the furnace is on until it’s warm enough to tunr it off, somewhere in Texas. Never had a problem with it not lighting, but did run out of Gas one time and it locked out as it’s supposed to do.( I only turn on one tank at a time)

  7. Gaylord

    I have been traveling with my refrigerator on for over 30 years. I have always followed the road signs and turned the system off when necessary. Crossing the Chesapeake bay bridge the toll attendant use to check to make sure the
    tank(S) were shut off. In recent years all the rules seem to be changing for no valid reason. The gasoline going into the carburetor is more dangerous than the RV system. I have never heard of a propane leak that you could not smell so this new so called safety feature is overkill.

    I think Bill Lemke low heat could be related to leakage or to much airflow to the radiator, either case prevents the heater from reaching its full capacity. I’ve had both these problems on vans and Class As, more so on vehicles with fresh air vents.

  8. GaryM

    A friend of mine installed a sliding barrier, (something like a big shower curtain) that went across the rig just behind the driver and passenger seat. That way the only area heated was the front, then later in the day they stow the divider next to the left side for easy passage back into the coach.

  9. codgerbill

    On another subject,
    When will we see some new RV shows from you?

  10. codgerbill


    What would be the problem with running the generator to supply a couple of properly secured electric heaters?

  11. Rich D.

    When asked: “Is it safe to run with the LP on/” I would have to ask “Is it safe to be parked with the LP on?” Same system, same results if there is a leak internally. If the leak was external you should be safer while moving! The key is, as the Dr. says; a properly checked and maintained system.