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How Does an RV Propane Furnace Work: A Simple Explanation

Fact checked by Ronal Dowens

how does an rv propane furnace work

Recreational vehicles (or RV) have been in trend these past years, especially for those adventure seekers who love camping without leaving the comfort of their homes. During the cold weather of winter, most people usually rest their RVs in their garage.

However, some adventurous people equip their RVs with an efficient propane RV furnace that keeps the air temperature inside the RV warm even during cold weather. How does an RV propane furnace work? How does its heating system function?

In this article, we will be discussing the principles of an RV Propane Furnace. We will also tackle a few tips on how to make your RV Furnace more efficient.

How Do the RV Furnaces Work?

For your information, every RV has a built-in heating system. The RV furnace can run on both Propane and electricity. In truth, Propane acts as fuel to generate heat. Meanwhile, RV furnaces use electricity but are not involved in any heating elements. It is only utilized for ignition and running the blower to allow the hot air to circulate in the RV.

Camper propane heaters (or RV heater) is an example of forced-air heater. It may seem complex, but in reality, a forced-air system is simple. It means that hot air is forced from the vent into the whole RV when the air temperature turns cold.

Aside from keeping the RV warm, the heat generated by the camper propane furnace prevents the freezing of the pipes and tanks.

Generally, propane furnaces are equipped with a blower motor, thermostat, sail switch, module board, air intake vent, and exhaust vent.

7 Steps Operate Travel Trailer Furnace


Step 1: Open the propane valve

We should open our propane valve slowly to allow the passing of propane into the furnace.

Step 2: Start Time/ Thermostat calls for heat

Next, make sure to set the temperature based on your preference. As the thermostat is set, the air current flows through its ON/OFF switch to the relay upon a call. The relay then flows through the heater coil within the relay circuit. It signals the module circuit board thermostat to activate, and the blower output energizes, then it starts.

Warning – When electricity is too low, the motor will not start.

Step 3: 15-second purge cycle

When the set temperature is reached, and enough air flows within the blower, the sail switch closes to allow the furnace to ignite. Once the temperature setting goes above the set temperature, the contacts within the sail switch open, signaling the shutdown of the ignition system.

The pre-purge cycle occurs for approximately 15 seconds to allow the combustion chamber to purge.

Step 4: 7 seconds ignition cycle and flame sense

In the next step, electricity will flow to the gas valve and ignite the electrode for 7 seconds. Once the module board verifies the main burner is successfully lit, the ignition will end while the gas valve and blower motor continue to run.

Step 5: 2 and 3 ignition cycles if needed

In cases where the module board does not sense a flame after 7 seconds, there will be a second 15-second purge cycle then a second Trial-For-Ignition sequence.

If there is still no ignition of the main burner after 3 Trial-For-Ignition, the gas valve will be de-energized while the blower will continue running for 3 minutes before shutting down in lockout mode.

Step 6: Heating cycle

During the heating cycle, the limit switch is closed. Once it opens and remains open for a while, the gas valve will close while the blower motor continues to run.

Step 7: 90-Second shutdown

Once the heat demand is reached, the gas valve is de-energized, and the flame goes out. The post-purge period begins 90 seconds after, then the blower stops.

How Much Propane an RV Furnace Consumes


If you are wondering how much propane an RV furnace consumes, here is a simple computation.

The propane consumption of the RV furnace depends on several factors, such as the size of the propane tank, how much gallon of propane the tank contains, and the British Thermal Unit (BTU) rating of the furnace.

Generally, a gallon of propane can last 95 hours at 1,000 BTU per hour. Hence, a gallon of propane can last up to 3.17 hours if your furnace has a BTU rating of 30,000 BTU.

So if you are planning to go camping for three days, how much propane would you consume if your furnace ran for 1 hour every morning and another hour every night?

Tips on Making Propane Furnaces More Efficient

Surely you want your RV furnace to function as efficiently as possible. Then, you can enjoy the hot air provided by your RV heater without spending much on propane to fuel up the heater. Then here are a few tips to have your heating system work efficiently.

Have your RV Furnace serviced by a certified technician at least once a year

If you have very minimal knowledge of how your RV furnace system works, why not let some experts handle it? By taking your RV to a mechanic shop, the technicians will be able to identify if there are any problems or leaks in your propane system. They will be able to fix the system before it worsens, saving you lots of money.

Listen to your furnace when the cycle is on the run

Before going out on a road trip, make sure to check for any squeaking or grinding sounds of your furnace. It indicates that your furnace is either not working efficiently, there might be loose screws, or worse, it is on the verge of breaking.

Check for visible soot

The presence of soot around your furnace’s exhaust vents could mean that it is not functioning efficiently. There could be improper mixing of fuel and oxygen leading to unburnt fuel, most probably due to obstruction on the pipes.

Aside from reducing the efficiency of your heating system, improper gas combustion may lead to carbon monoxide accumulation, resulting in severe injury.

Propane, when appropriately burnt, will not produce carbon monoxide. But when obstructions or leaks happen in the pipes, improper gas combustion occurs.

Hence, it is important to clean your furnace or have it serviced if soot continues to appear on your vents.

Regularly clean your furnace

Dust and other small particles will inevitably be present in your RV. By regularly cleaning your RV furnace, either before going on a road trip or at least every three (3) months, you prevent these particles from blocking your vents that could restrict proper air intake and eventually reduce the efficiency of your RV furnace. Clean your vents and furnace by using a vacuum with a brush attachment.

Improve your RV’s insulation

Place reflective insulation on your RV’s window. It will allow you to trap more warm air inside your RV. If you have an additional budget, you can opt to replace your single-pane windows with a double-pane.

Provide an additional heat source

If your budget permits, you can also provide additional heat sources such as electric heaters. This will aid RV furnaces to make the air hot.

Final Thoughts

If you plan on going on a road trip or camping with your family or friends in your RV, then make sure that you do not freeze on a winter night. Invest in a quality RV Propane Heater with Thermostat so that you do not have to worry about chilly nights again.

This article gave you a run-through on “how does an RV propane furnace work?” and how to make it perform more efficiently. Hopefully, this has helped you in planning your trip with your RV a whole lot more memorable.

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