RV Furnace Won’t Ignite? Here’s What To Do

Many people enjoy traveling year-round in their trailer. For year-round travel, an RV’s furnace comes in handy. It can keep you warm at night and can make you more comfortable during the day.

If you already own one, there may be times when your RV furnace won’t ignite. What should you do in situations like these? With a little mechanical knowledge and patience, you can get to the bottom of the problem.

You may not be able to fix the problem yourself, but you should know why your furnace isn’t working so you can do some camper furnace troubleshooting methods.

rv furnace

RV Furnace Won’t Ignite? Common Problems with RV Furnaces

There are a few reasons why your RV furnace may not be working properly. Here are some common problems:

  • The propane tank has issues.
  • The propane line isn’t functioning properly.
  • The pilot light and thermocouple have worn out.
  • Your thermostat has problems.
  • The airflow is damaged in the furnace.
  • You’re experiencing basic electrical problems.

Keep in mind that propane can tighten or contract in colder climates which reduces pressure inside the furnace. Therefore, if you’re using the RV in winter, you may face issues with your propane tank.

If the temperature outside is too cold, your propane tank can freeze entirely. In situations like these, you should try bringing the tank inside the RV to warm it. You can’t always bring the tank in, especially if it’s a heavy tank fitted with nuts and bolts which can be the case.

How to Fix an RV Furnace

Troubleshooting RV furnaces can get a little tricky, but with the right tools and a little focus, you can get the job done!

Check the Propane Tank and Gas Lines

To check if there’s a problem with your propane tank and gas lines, start by determining if there’s adequate gas running through your lines. To do this, switch on your internal propane range and connect your RV refrigerator to propane or ignite any similar appliance that works off the same gas line.

Switch on your furnace. If you don’t know how to light a propane furnace in a camper, then simply switch on your tank, press the pilot button, and ignite the pilot. If your appliance works, then you’ll know it isn’t a problem with your propane tank or the gas lines but if you find that there isn’t adequate gas in the system, inspect the external tank.

How to Fix It

It’s fairly common for a propane coupler to loosen in cold climates. This is because metal usually contracts in the cold. To fix this problem, here are some RV propane furnace troubleshooting methods. Start by checking all your propane couplers and making sure they’re tight.

There will be a clear smell of rotten eggs if there is a leak in any internal line in your RV. However, if the leak is on the mainline (i.e. outside), it will be harder for you to notice the smell. Therefore, try running your hand along the line to check if there are any nicks, cracks, or tears.

Check the point where the propane line meets the camper. Occasionally, gaskets can wear out a hose, initiating leaks.

A temporary fix could be wrapping the leak with duct tape. This dometic RV furnace troubleshooting method can get you through the night at best so ensure you fix it as soon as possible.

Check the Ignition System

An igniter requires a minimum of 10.5 volts to work effectively on a propane furnace. If the onboard batteries are worn out or are damaged, there won’t be an adequate source of energy to ignite the system.

Another possibility for your RV furnace igniter not working is the circuit breaker has tripped. You should inspect the breakers and ensure that they’re on for the thermostat and furnace. This can cause RV heaters like the Keystone RV furnace problems.

How to Fix Electrical Failures in Ignition

If your battery is not producing more than 10.5 volts, switch to a backup battery that can. If you’re extremely desperate, use the 12-volt battery from the tow vehicle or motorhome.

Remember, this is the last resort. It’s best if you try and find a backup battery. You wouldn’t want to be stuck outside with a discharged vehicle battery as well.

Check Wiring To See if It’s an Electrical Problem

If your batteries are working fine and delivering over 10.5 volts, then you should check if the wires are loose or damaged. Remember, you must be careful while inspecting the wires.

Start with the furnace and check every connection and wire. The vibrations created from driving may have dislodged or loosened a wire.

If you haven’t spotted anything out of the ordinary, move on to check if there are any problems in the wiring between the battery and furnace ignition system. Remember, you are dealing with electricity. Any mishap could lead to a fire. Therefore, keep a camping fire extinguisher in your RV at all times.

How to Replace Damaged Wires

If you see that a wire is loose or is slightly torn, you may need to tighten it with a wire nut, clip, or strip. If the wire is damaged, you might have to splice it, patch it, or change the entire wire.

Changing the wire is a little technical. It’s alright if you find this step challenging. Go through these steps and try it yourself.

  • Take a wire cutter and remove the section of the wire that’s damaged.
  • Carefully pull back close to an inch of the protective layers on the two sections of the exposed wire.
  • Take a new wire that has the same specifications as the older one and stick the protective layer on both ends.
  • Braid each end of the wire together.
  • You can either solder and tie the new wire using electrical tape or twist them with a little wire nut.

You can use this for troubleshooting Atwood RV furnaces. This is a handy travel trailer furnace troubleshooting method as well.

Check if the Battery is Running Low

An igniter requires at least 10.5 volts to function properly. Take a multimeter and check the voltage of your battery. If it’s less than 10.5, then you most likely have a problem with the battery.

If your battery isn’t delivering adequate power to the propane furnace or thermostat, the system won’t ignite which can cause the fan inside to function slowly or stop working entirely.

Check if the Battery Terminals Are Corroded

After checking the status of your batteries on the multimeter, inspect the batteries for corrosion or other damage. With time, electrolytic corrosion creates a greenish, white, or grayish coating on the battery terminals.

If you leave this step unchecked, the electricity being delivered from the batteries will be affected. All you need to do is routinely clean the area to strengthen the connection between the battery and the furnace.

How to Clean Battery Terminals

  • Create a loose mixture of water and baking soda.
  • Safely disconnect the wires from the region that’s corroded.
  • Grab an old toothbrush and apply a baking soda mixture to it.
  • Clean the area meticulously with the toothbrush until you’ve scrubbed away the corrosion.
  • Take a clean towel, preferably a paper towel, and clean the baking soda off the terminal.
  • Safely connect the wires again. Ensure that the wires are delivering power to the furnace and thermostat.

You can try this for duo therm furnace troubleshooting and other RV furnaces as well.

Check the Thermostat

The thermostat is probably the most important component of your RV furnace. It is often called the brain of the furnace system. You should always ensure that your thermostat is functioning well.

Tighten Any Loose Connections

If your thermostat is blinking continuously and displaying highly inaccurate readings, then you probably have a loose wire. Loose wires are one of the lead causes of your RV heaters like the Forest River furnace not working.

To check if you have a loose wire, safely remove the thermostat from the wall and inspect your wires and connections. You will find a lot of small nuts and screws that hold these connections together. If you spot a loose wire, simply tighten it again.

If your RV heater or duo therm furnace won’t ignite, try switching the thermostat on and off. Switch the thermostat off and switch it back on after 10 minutes. This can reset the gas flow.

Replace Thermostat Batteries

In some camper trailers, the 12-volt batteries aren’t connected to the thermostat. These systems often run on AAA or AA batteries.

If you have a problem with the batteries, then you might see the screen on the thermostat blinking continuously, not responding even after pressing a button or going entirely blank. If that’s the case, then you might need to change your batteries.

Use the right configuration of batteries for your thermostat. While you’re replacing the batteries, have a look at the terminals as well for corrosion or other damage.

After replacing the batteries, switch the system back on. You will need to wait for some time and let the machine reboot its internal system. If the problem was low batteries, then your thermostat should function perfectly after replacing them.

Check the Pilot Switch

Pilot switch issues are sometimes connected to airflow or safety sensor problems where the RV furnace blower comes on but won’t ignite. The RV pilot light is usually located at the bottom of the furnace. To deal with a pilot switch problem, you must first check the sail switch and thermocouple.

A sail switch is a component that is designed to detect the level of airflow. If you have an RV furnace pilot light problem, the sail switch will prevent the furnace from igniting, but the furnace blower will function. The sail switch will most probably overheat or crash if there isn’t adequate airflow.

Check the Sail Switch

As the name suggests, a sail switch is a switch that determines if there is adequate airflow in the furnace. The sail switch stays in two positions, either “on” or “off.”

While checking the sail switch, ensure that there isn’t an accumulation of dirt or grime. If there is, clean the area with a dry cloth. Now, move to the vents and ensure that there isn’t a build-up of soot or dust. Check the RV exhaust vent too. If dust or soot has built up in the area, there is a chance your furnace is functioning ineffectively.

After you have cleaned the area, switch the thermostat or furnace off and reset the entire system. Give it a minute or two and switch the system back on. Your system should start functioning normally. However, if your fan is working but the furnace is not igniting, you may have a serious problem with the sail switch and need to replace it.

A basic RV heater troubleshooting method for your sail switch is ensuring that the battery is powering the furnace with 12 volts of electricity. Have a look at the breaker box and check if the fuse is worn out or is blown. If so, you will need to replace it.

Check the Thermocouple

A thermocouple emits a millivolt signal and determines the voltage whenever the resistance fluctuates. A change in resistance is confirmed by the furnace’s system. Essentially, a thermocouple’s job is to make sure that the flame ignites at the pilot light before activating the furnace valve.

If a thermocouple wears or burns out, the pilot light goes out because the furnace doesn’t release any gas. Otherwise, a thermocouple won’t function correctly because of the accumulation of dust and soot around the area. It’s quite challenging to visually check if a thermocouple has worn out. However, you’ll get a strong smell of rotten eggs if you turn the heat on. The smell is usually a tell-tale sign of a broken-down thermocouple.

Check with a Multimeter

If the thermocouple is clean and all other devices are connected correctly but still won’t work, then you may check the thermocouple with a multimeter. If the multimeter shows that power is not going through to the thermocouple, you probably need to replace the part.

Fortunately, thermocouples are easily available and are quite inexpensive. Most electrical stores and RV stores will have thermocouples for your camper trailer. If you don’t find a thermocouple anywhere, it’s best if you run the RV with in-built heaters on or use a sunflower heater for the night.

Check the Blower Fan

There are a few issues that could affect your blower fan. If your RV is old, the motor of your blower fan might be worn out even though it is a little warm. The blower fan will not work as fast as it used to if the motor is worn out. This happens when the bushings or components within the motor are damaged.

It doesn’t necessarily have to be an issue with the motor. There could also be a problem with the wiring. Check the blades of your fan to ensure that dust or soot hasn’t collected around it. If there is dust, clean the area thoroughly with a cloth. While cleaning, feel the casing of the motor. If the bearings or bushings are not functioning properly, the fan will heat up quite a bit.

Most blower fans are built with wired connections. One of these wires may have been dislodged or loosened. This can stop the fan from operating. If a wire is loose, there may be decreased power in the fan. The easiest way to fix a broken or loose wire connection is to solder them back into place. Restart the entire system and check if the blower fan is working normally.

How to Deal with a Dead Blower Fan

If the fan has died or is making a loud irritating noise, you will probably have to replace it. This entails installing a new fan that is meant for the model of your trailer.

It’s easy to find a new blower fan for your RV, especially if you take the old one into a hardware store. Otherwise, you will need to place a special order for a new fan. It could take a few days to get to you. Until then, you should have a quick backup plan to keep yourself warm.

How to Replace a Dead Blower Fan

Replacing a dead blower fan is not easy. It is a quite challenging RV furnace troubleshooting method. If you’re not comfortable with doing this yourself, simply take the RV to a professional mechanic. The safety of your RV is extremely important.

The following instructions are meant for those with a substantial amount of mechanical knowledge.

  • Switch off the circuit breaker.
  • Unfasten all the nuts and bolts that are holding the blower fan in place.
  • Remove all the wires that are connected to the back of the fan. You might need a soldering iron or heat gun.
  • Connect the old wires to the ports of the new fan. You may need to solder the wires in position if required.
  • Place the new blower fan in its old position and tighten it with the nuts and bolts you removed earlier.

After doing this, you can switch on the circuit breaker. The furnace will take some time to create hot air and ignite. Be a little patient and wait for the furnace to run like before.

How To Stay Warm If the Furnace Goes Out

There are times when your RV furnace can die or wear out even though you kept it in proper condition. Checking your furnace systems before going on a trip is best practice but it doesn’t guarantee that your furnace system will keep working perfectly. Your furnace can stop functioning at any time. To eliminate the risk of suffering in the cold, here are some tips on how to stay warm if your furnace goes out.

Keep Your Exterior Seals in Good Condition

There are rubber seals that are stuck around the doors, windows, and sides of your RV. These seals prevent cold air and other elements from entering your trailer. Lubricating and cleaning these seals is therefore important.

If these seals have hardened or have nicks or tears in them, keeping out cold air is practically impossible. Always clean and lubricate your exterior seals to prolong their lifespan.

Buy Painter’s Tape

This is not a permanent fix to keep the cold air out. It’s more of a quick fix to keep yourself warm until you fix your furnace. The greatest advantage of using painter’s tape is there won’t be glue stuck to the surface you’ve applied it on.

If there’s a cold draft coming in from behind an appliance in your RV, simply stick the tape over that area. You can remove the tape once your furnace is fixed.

Use Rugs

Rugs are a valuable tool in helping you stay warm when your furnace breaks. Place thick rugs in the areas you walk in most often. These rugs will protect your feet from the cold floors of your camper trailer.

Utilize Your RV’s Heat Pumps

Most RVs have air conditioners on the roof that can either cool or heat the trailer. If your furnace goes out, using the RV’s heat pump is a great way to stay warm for the night. Remember, heat pumps aren’t that effective in extremely cold temperatures. They work best when it’s close to 40 degrees Fahrenheit outside.

To keep your room warm, set the temperature of the heat pump to about 52-54 degrees Fahrenheit.

Pack Warm Clothes

You can travel with an RV throughout the year, but they aren’t specifically made to combat the cold. The easiest thing you can do to stay warm in case your furnace breaks is to wear warm clothes. You should be carrying them anyway if you’re visiting cold places.

Here are a few clothing reminders to keep you warm on your next trip:

  • Bring at least two thick winter sweatpants and one to two hoodies or sweatshirts.
  • Don’t roam around barefoot in your RV. Wear slippers and a thick pair of socks to keep your feet warm.
  • Carry a thick blanket to cover yourself with at night when you go to sleep.


Your RV furnace can break down at any time, even if you take the right precautions. You may be able to fix the problem yourself, but sometimes you will have to get it fixed by a professional.

If this happens, don’t panic. See if you can fix the problem yourself. If you can’t, use the tips we mentioned to stay warm and take your RV to a professional as soon as possible.

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