Camper Furnace Guide: How It Works, Troubleshooting, and Off-Grid Power
Camper furnaces are the main heat source for cold-weather camping. They typically run on a mix of propane, with 12V battery power for the fan and controls. If you are off-grid camping, this can be a problem because the furnace will keep burning propane, but the electrical components can drain your house battery overnight.
This article will go over how camper furnaces work, common problems and solutions, and how to keep your furnace running when camping off-grid.
How Does a Camper Furnace Work?
The most common type of camper furnace is the forced-air propane camper furnace. Propane is the fuel for heating, and the thermostat, blower fan and ignition are powered by your coach or house battery in 12V DC. The fan then moves the hot air from the furnace through the ductwork and vents to heat the living space.
Propane vs. Other Camper Heating Options
The three common types of heat sources for campers are:
Propane forced-air: The most common type of camper heating system.
Hydronic: A closed-loop boiler system that heats water for circulation throughout the RV.
Catalytic or portable space heaters: Simpler heating solutions for small spaces.
Electric heating solutions require either shore power or a large battery pack, and draw significantly more power than a propane furnace. For a good idea of how much power different appliances draw, refer to this article on camper air conditioner watts.
How Much Battery Does a Camper Furnace Use?
Using a camper furnace propane means that the propane itself is doing the heating. The 12V DC power required to run the fan and electronics is minimal. However, you might be surprised at just how much power this can add up to over the course of a night when the furnace is running. A typical house battery will be drained overnight if the furnace is running. You should refer to your furnace manual to see how much current your particular model draws.
This is why it is important to practice good battery management when camping off-grid. A propane furnace that is powered by 12V electricity will cease functioning when the battery is drained.
How to Keep Your Camper Furnace Running Off-Grid
When camping off-grid, the battery is your weakest link. The furnace needs a source of propane fuel as well as 12 volts of power to operate. A portable power station can help to alleviate some of the pressure on your house battery by providing an alternative power source that can be charged via solar panels.
Not all off-grid winter camping adventures are fully off-grid. If you are staying at a trailer park, you might have access to shore power. However, if you are venturing into the wilderness, you should always plan your power needs ahead of time.
Maintaining Furnace Power During Extended RV Camping Trips
Let’s imagine that it is a January night and you are at a remote campsite. It is below freezing outside, and the furnace in your RV is cycling on and off to keep the temperature inside the coach at a reasonable level. The fridge is humming happily along with your laptops and other devices. When you wake up in the morning, you notice that the lights in the coach seem dimmer than usual. You worry that the RV’s house battery may have been depleted overnight.
This is where a bigger power station comes in handy. If you're camping for a few days in the dead of winter, consider a larger-capacity power station, such as the EcoFlow DELTA 3 Max Series Portable Power Station (2048Wh). The Max Plus model has a capacity of 2,048Wh and a 3,000W rated output. This will allow you to power most of your essential devices and reduce the load on your house battery.
The DELTA 3 Max Plus weighs approximately 22 kg, making it better suited to RVs and vehicle-based camping than to backpacking. Make sure to size the power station according to your needs. High-power electric space heaters will quickly overwhelm a low-capacity inverter.
Supporting Furnace Battery Needs in Smaller Campers and Vans
Take a weekend getaway in a small camper van. You've got enough room for a couple of nights, but you still want your mobile devices charged, a few lights, and something extra. Winter adventures like this might take you to a place like Pedder Bay RV Campground.
A great lightweight alternative for smaller campers is the EcoFlow DELTA 3 Classic Portable Power Station (1024Wh). This model provides 1,024Wh of battery storage and delivers up to 1,800W of power. The DELTA 3 is rechargeable from AC, solar, car, and generator.
Keep in mind that it's not a whole RV camper furnace heating solution, just match the unit to your devices, and runtimes will vary.
Common Camper Furnace Problems and Fixes
Some issues are simple fixes. The following section will go over the common fixes you can attempt, while more internal parts like circuit boards, switches, and igniters should be handled by an RV technician. If you ever smell propane, turn off your tank and call for assistance.
Furnace Keeps Shutting Off
One of the most common issues is a dirty sail switch. When the furnace initializes, The sail switch verifies that the blower is producing sufficient airflow before ignition can proceed; if the vent is clogged with dust/debris, the unit will begin its ignition sequence and then quickly shut down. This vent often doesn't have a filter on it, so it's important to vacuum out the dust at least once a month and more often in the cold-weather season. If the switch itself is faulty, a professional will need to replace it.
Furnace Won't Turn On
Check the following:
Make sure the thermostat is set to either "Heat" or "Furnace" in some models.
Confirm that the 12V battery is charged.
Make sure that the fuse in the 12V fuse panel for the furnace isn't blown.
Loose wiring and circuit board failure should be diagnosed by a professional.
Furnace is Blowing Cold Air
It's normal for the furnace to blow some cold air at the beginning and end of the heating cycle. At the start of the cycle, the fan is used to clear out the system, which can take up to 5 minutes. If the furnace fails to ignite 3 times in a row, it will lock out and needs to be reset by turning it off at the thermostat and then back on.
Other things to check are:
Make sure propane is turned on and the tank isn't empty.
Check the exterior exhaust vent for blockages like soot or nests.
On extremely cold, damp nights, the propane regulator can freeze up. Use a tank cover or tank warmer.
Conclusion
A camper furnace uses propane for its heat source and a 12V battery for the thermostat, blower fan, and igniters. Many of the common issues can be resolved by checking a few simple things, but keep in mind that anything relating to the internal workings of your furnace should be left to a professional RV technician. When planning cold-weather adventures, budget extra battery power for your off-grid excursions.
FAQs
How does a camper furnace work?
Most camper furnaces are forced-air systems. The fuel source is propane, and the 12V battery powers the thermostat, blower fan, and igniters. The blower circulates the heated air throughout the RV.
What type of fuel does a camper furnace use?
Most camper furnaces use propane as their heat source, while a 12V DC battery powers the blower fan, ignition system, and controls.
Why does my camper furnace keep shutting off?
One of the most common reasons is a dirty sail switch. The sail switch senses the airflow at the return vent. If the vent is dirty, it won't register that the furnace is circulating warm air and will shut off. Make sure to vacuum the return vent at least once a month or more often during cold-weather camping. If the switch is faulty, an RV technician will need to replace it.
Why is my camper furnace blowing cold air?
It's normal for your furnace to blow some cold air at the beginning and end of the heating cycle. The furnace will blow cold air for about 5 minutes until the system has completely cycled through. If the furnace is failing to ignite 3 times in a row, it will lock out and needs to be reset by turning it off at the thermostat and then back on. You should also check that you have propane turned on and that the tank isn't empty. Check the exterior exhaust vent for any blockages.
How much battery does a camper furnace use?
The 12V battery is used to power the blower fan and electronics. The draw on the battery is minimal per hour but can add up if you're using the furnace throughout the night. Check your furnace manual for its draw on the battery.