What’s the difference between “gas heat” and “electric heat” in an RV?

You’ve probably seen these terms scrolling through the modes in your digital wall thermostat. You might also have a setting for “heat pump.” On an analog thermostat, these modes are likely different positions on the linear selector switch.

Unfortunately, these terms probably don’t show up in a glossary in your Owner’s Manual. Some thermostats only have one or two of these modes; some only have a single mode for “heat.” What gives?

• Gas heat = Furnace (usually propane-fired)
• Electric heat = Could mean heat pump (electric) or heat strip (electric)
• Heat pump = Heat pump operation only (electric)

These terms are not standardized among manufacturers, so again, the terminology does depend on your thermostat or command system (FireFly, In-Command, etc.). There are also unique heating systems, such as hydronic heating systems, that may have different commands and modes .

To understand these terms, you need to understand that there are several methods of space heating your RV. Let’s turn up the heat!

5 Types of Heating Options for Campers and Coaches

1. Furnace

Furnaces are the mainstays of the RV industry. These furnaces are generally forced-air furnaces that burn propane fuel. They circulate air throughout the RV, heating it up to 140+ degrees as it passes through the furnace heat exchanger.

Furnaces can be ducted or direct-vented. If ducted, they can have individual 4” ducts (sometimes 2” ducts to underbody tanks) or a central plenum. Ducts are normally run through the floor or through cabinets, where the heat exits through 4” round or 4”x10” rectangular heat registers.

>>> READ MORE: Furnace Overheating? Double-Check Your Furnace Flexible Ductwork!

Furnaces are rated by BTU output: 20,000-40,000 BTU is a common size range. (For reference, the average stove top burner is about 6,000-8,000 BTU). Some larger RVs, such as Class A motorhomes, may have multiple furnaces. 

2. Heat Pump

A heat pump is just an air conditioner that can run in reverse. Rather than stealing heat from the indoors and exhausting it outdoors, like a normal air conditioning cycle, it does the opposite: It absorbs heat from the outdoors and exhausts it indoors. And yes, even when it’s 40 degrees outside, heat pumps can still extract heat from outdoor air (thanks to the wonder of modern refrigerants).

Most RV heat pumps are just standard rooftop air conditioners with a reversing valve, but they also come in basement models, like the Dometic Cool Cat or Pioneer Under-Bench Heat Pump. Basement models are more common in Class B motorhomes and van conversions.  

However, unlike modern residential heat pumps (I see you, Mitsubishi HyperHeat!) that are effective down to -20 degrees Fahrenheit, RV heat pumps are best suited for chilly mornings between 45-65 degrees. They are NOT effective at frigid conditions, and in fact, they can be damaged if operated at subfreezing temperatures. They typically don’t warm the incoming air more than 20 degrees, so if the inside of your RV is 55 degrees, a heat pump may only warm the air to 75 degrees or so, and that air will NOT feel warm against your skin.

Unfortunately, heat pumps really aren’t very useful in an RV except for chilly autumn or spring mornings. For anything colder, the furnace is far more effective – and less expensive to operate.

3. Heat Strip

A heat strip is just an electric space heater, like the $40 ceramic space heater you probably have stashed in a closet somewhere in your house for overnight guests. Most RV air conditioners can be equipped with an optional heat strip resistance heating element, which is positioned in front of the evaporator coils.

Heat strips in a rooftop air conditioner are, quite frankly, a waste of money. They typically only raise the air temperature by 6-10 degrees. And remember, heat rises, so electric heat strips in an air conditioner at ceiling height are heating the WRONG layer of the air. You’re better off plugging a regular ceramic space heater or radiant space heater into a wall outlet and setting it close to floor level. 

4. Hydronic Heating

A few RVs use a hydronic heating system, like the Aqua-Hot, Oasis, or Truma Combi. These systems are highly customizable and may run off propane, gasoline, diesel, or backup electric energy.

A hydronic heating system heats a liquid with a boiler and then pumps that now-hot liquid into different air heat exchangers. The Aqua Hot uses forced-air heat exchangers, while the Combi relies more on natural convection aided by thermal fins.

Hydronic heating systems are beyond the scope of this article. They are mostly used in premium Class A motorhomes and a few European-inspired miniature travel trailers. Most have their own control panel not integrated into a standard air conditioning RV thermostat. 

5. Mini Split

Mini splits are, at best, at honorable mention. They haven’t made significant inroads into the RV industry yet. A few brands include Nomadic Cooling and the aforementioned Pioneer. 

A Few Key Takeaways about RV Heating Modes

Alright, is your head spinning yet? Let me leave you with a couple of key takeaways:

In most RVs, air conditioners are mounted on the roof; furnaces are mounted at floor level. They do not share any ducting. However, if you have heat pump air conditioners, then you can use your rooftop A/Cs in heat pump mode as “chill chasers.”

Most furnaces use propane as fuel. Air conditioner heat pumps, obviously, need electricity. Hydronic heating systems on coaches may use the engine fuel: gasoline or diesel.

Furnaces may have their own independent thermostat, but most are integrated into the main wall thermostat. 

What’s the Difference Between Gas Heat and Electric Heat in an RV?

In summary …

• “Heat” mode typically controls your furnace. More explicitly, sometimes the furnace is called “gas heat.”
• “Elec heat” can refer to either a heat strip or heat pump. Refer to your Owner’s Manuals for more information.
• “Heat pump” refers to the heat pump, of course.

Many thermostats will also show various zones. If you have two air conditioners, for instance, one is often named Zone 1 and the other is Zone 2. Cooling between zones can be controlled independently. 

>>> READ MORE: RV Furnace Not Turning On? RV Tech Shares 7 Easy Tricks!

However, zoned heating is a little more complicated. In many RVs without heat pumps, there’s no such thing as zoned heating. Sorry! If you’re relying on a furnace, most RV ducting systems don’t have dampers or adjustable vents. In fact, most furnace OEMs forbid you, the customer, from closing off any heat ducts! And in the few cases where an RV uses multiple furnaces, they are often tied together into a single zone. If one turns on, both turn on.

Unfortunately, this is where I leave you to consult your Owner’s Manual. There are just too many variations. Sometimes, RVs have multiple thermostats: One to control the air conditioners, and another to control the furnace! Sometimes the thermostats are analog, sometimes digital. But if your RV is somewhat “normal,” then the rules above should apply to you.

My Final $0.02 on Gas Vs. Electric Heat in an RV

Note this all applies to air (space) heating. You may have dedicated appliance heating like tank heaters, for instance, which are usually controlled by off-on rocker switches from your control panel and are COMPLETELY separate from your primary heating system.

My two cents are to trust your furnace for primary heating. Heat pumps and heat strips are often useful as “chill chasers” or to maintain a warm interior as the outside temperatures drop overnight. They make for poor primary heating sources. Furnaces are reliable, powerful, and less expensive to operate.