What to Do If Your RV Furnace Won’t Ignite

Last Updated on December 31, 2021 by Douglas

Traveling around the world in an RV is a lot of fun. But it does expose you to the elements. You need every tool at your disposal to fend off these dangers. One such tool is an RV furnace. RV Furnaces are a great way to keep your RV warm during the winter. They allow you to travel in cold locales that often have breathtaking scenery without putting your health at risk.

However, at one point or another your RV furnace might fail to turn on. When this happens, you would be left without any kind of heating source and you won’t have any hot water either. This can be a huge problem when you consider the kind of impact it can have on your traveling plans. In this article we will be talking about some of the most prevalent problems that can occur with RV furnaces. We will also be telling you how you can deal with these problems effectively.

Common RV Furnace Ignition Problems And How to Deal With Them

A lot of RV furnace problems are actually quite common. When they occur they would most definitely worry you, but there is no reason to fret. The fact that they are commonplace is a good sign since it means that you can confidently fix the issue and get your RV furnace back up and running again. There are four main problems that can occur with your RV furnace. These have to do with propane supply, electricity supply, battery problems and problems with the thermostat. We will be discussing each of these problems in detail below and giving you some steps that you can take to fix these issues.

Propane Supply

This is the first issue that you should try to diagnose. An interrupted supply of propane means that the RV furnace would be left without fuel. It obviously can’t function with an adequate fuel supply, which is why dealing with this issue first is so important. Generally a lack of supply could result from your propane tank being defective. In order to ascertain whether or not you are getting any propane from the tank, try to light the stove. If it uses the same fuel as the RV furnace, which it ideally should, then it will ignite. If this happens you can move on to other issues that may be occurring.

If the test confirms that propane supply has been interrupted, the next step would be to go out and check the tank. Sometimes propane tanks go empty in a shorter period of time than you would expect. Whenever this occurs, you would need to buy a new tank. However, a propane tank that finishes a lot earlier than it should could be a sign of some other underlying issue.

If it’s very cold outside, this could be the reason why the propane tank isn’t working. The colder it is, the less effective propane would be. At certain temperatures it might just freeze entirely. The only solution here would be to bring your propane tank inside where it’s a bit warmer and allow the propane inside it to melt. This will be a major undertaking since most propane tanks are very large. There is one thing that you should do before you to try this out.

There is a good chance that the problem lies in your propane lines rather than the tank itself. One sign that the problem might be in your lines is if you notice any kind of strange smell. Propane smells like rotten eggs. So if you smell anything like this, you can be reasonably confident that there is a leak in the propane lines. This is a very dangerous issue. The smallest spark can cause a huge explosion. Leaks are also dangerous because propane is not good for you to breathe. Breathing too much of it could cause respiratory issues as well as other problems that can occur when you don’t get an adequate supply of oxygen.

It gets a bit trickier if the propane lines are outside. Because you wouldn’t be able to use the smell test to accurately judge this sort of thing. In order to make sure that there is no leak in your exterior propane lines, run your hand over the pipes. Any leak would be releasing propane at a pretty high pressure. You would be able to feel it on your hand, after which you can wrap insulation tape around the leak and stop it for good.

There are a lot of causes for leaks. They occur quite frequently because the movement of the RV can sometimes loosen the nuts and bolts holding the propane lines together. Most propane lines are made of several separate components. If one bit comes loose, this would start leaking all of your propane. These kinds of leaks usually occur outside, so you should check carefully to make sure you find this. Failing to do so could mean that your propane tanks get drained time and time again before you get to use them properly. Propane is rather expensive so you don’t want to waste any of it.

Once you have checked all of the lines, you should have a rough estimate of what the problem is. Not finding any leaks means that the problem is most definitely in your tank. You might want to think of a solution that would keep the tank warm such is placing it indoors. If it constantly freezes over, this would limit the amount of time during which you would be able to leave your RV furnace on.

This is something that you should take very seriously indeed. Your RV furnace going off in the middle of the night could lead to some pretty dangerous situations. Many people suffer from hypothermia because their RV furnace turned off while they were asleep and the RV got extremely cold. Remember that RVs are made out of metal which means that they have a tendency to get really cold if they’re not being warmed from the inside.

Electricity Supply

This is an issue that has even more causes than an interrupted propane supply. Your RV furnace would need some kind of an ignition spark in order to function. An electrical source is needed to create this spark. Only a small spark is required but you should never try to create it manually. This could create some massive issues such as causing a fire if the propane has started to leak out into your living space.

Creating this spark causes a bit of an electrical surge. If your electrical system wasn’t primed to handle such a surge it might cause the circuit breaker to trip. Try checking the switchboard to see if this has happened. A tripped circuit breaker is an easy enough issue to resolve. If the circuit breaker has not been tripped, though, a more serious problem might have occurred. You can try using your car’s battery here to start the RV furnace up. Be very careful while doing this, though. Doing it too often could drain your car battery. This would result in you not even being able to start your car which is a very risky situation to be in if you’re not all that close to civilization and have no other means of getting there.

Problems with your wiring can also cause an interrupted supply of electricity. This is often because of damage that has been done to the wires. It would take a lot of time to find the issue, but trial and error might just be your only solution here so you should give it a shot. Follow all of the wires that connect to your RV furnace and see if there are any breaks in them. Replace any wires that look like they have been damaged in some way.

Driving an RV results in a lot of motion inside the car. The wires of a RV furnace are usually not equipped to handle this much jostling. Starting your search with the wires right next to the RV furnace would be a good idea. Since these wires are usually the ones that come loose. Chances are that they’re not really damaged, they’ve just been knocked loose when you hit a bump in the road. This is a good sign since it means that you can just reconnect the wires and then call it a day.

You might also have put in a wire that’s too weak to handle the current. RV furnaces need at least 10 volts to be able to start. Some wires are too thin to conduct such a current. If your circuit breaker was tripped but you flipped it back up and tried again, this could be the cause of your burnt wire. You will probably notice the smell of melting plastic if an issue like this has occurred. When you replace the wire, make sure that you use one that’s sturdy enough to handle this strong of a current. Otherwise you might just end up facing this problem all over again.

Battery Problems

As we have already mentioned above, your RV furnace needs at least 10 volts for a spark that’s large enough to ignite the propane. You can use a multimeter to check the level of volts that your battery is sending out. Most batteries can easily provide the 10 volts required. If the amount of volts you’re receiving is any less than this, chances are that your battery is running low. It might even be dead which would be a huge issue to deal with. Try checking your battery every day or two to make sure that this issue never occurs.

You should always have a spare battery on hand. That way there would never be situation where your battery is dead and you are unable to ignite your RV furnace. If your battery is dead, you should replace it immediately and try turning your RV furnace on. If the battery was not sending out 10 volts, the new battery should do the trick. The RV furnace should turn on and work perfectly, and if it doesn’t then check the propane tank just to be on the safe side. Call an expert if all else fails so that they can come and deal with the issue in their own professional capacity.

Taking a look at your batteries should tell you if even need to check the voltage. Any sign of corrosion on your batteries probably means that that’s your issue right there. Corrosion inevitably builds up on batteries over time. It would have a greenish grey tinge to it. It prevents volts from being taken from the battery to your RV furnace. Hence, your battery isn’t dead. It just has a lot of corrosion that needs to be dealt with.

All you need to do here is clean the corrosion buildup from the battery. This is easy enough to do. You don’t even need any special tools or materials to do it. Don’t use soap, though. Soap is alkaline and it can further corrode your battery. Use baking soda instead. Mix the baking soda into some water. All you need apart from this mixture is a toothbrush. You can use this toothbrush to scrub the mixture onto the battery. This would loosen up all of the corrosion.

Before you start the cleaning process, make sure that you’ve disconnected the battery first. Not doing so would result in a really nasty electrical shock. It might also kill your battery. You wouldn’t be able to drive if this happens. The shock can also cause some serious injury. Disconnect all wires from your battery so that you can clean it safely.

The toothbrush can loosen up the corrosion but it won’t clean it up entirely. Use kitchen roll or some other highly absorbent tissue paper product to wipe up the loosened corrosion. A single wipe should reveal a shiny, clean surface underneath. Just like you might see in the ads! Give the battery a thorough once over with the toothbrush and baking soda mixture. Once you have covered every inch of the battery, wipe all of the mixture off. Your battery would be left pretty much spotless. You should do this every few months. Getting rid of corrosion is easy but if it happens too frequently it can damage your battery.

Finally, hook the battery back up and check if everything is working. Anything that was previously connected to the battery should work fine. If it doesn’t work, you might have done the wiring wrong. Check for any issues and replace wires that might have been damaged.

Thermostat Problems

If everything else looks fine or if you have fixed any issues that you found only to still not have your RV furnace working, the problem would most likely lie in your thermostat. These devices are crucial to the functioning of your RV furnace. They are built in fail safes that boost the safety level of your RV furnace. They also help give you more control over the internal temperature of your RV. Your RV furnace would automatically turn off once it detects that it has reached the temperature that your thermostat has been set to.

The most common problem that can occur with thermostats is that they run out of battery. They are very durable devices so the chances of them breaking down are slim. Replace the batteries and see if that fixes things. Your thermostat should turn back on once you have put the batteries back in. Remember that thermostats are never going to be attached to your main batteries. They usually function on disposable batteries. AA batteries are most commonly used. However, AAA batteries have also started being incorporated into thermostats. These batteries are smaller which helps to make the thermostat more compact. If you have a smaller RV or camper, chances are that your thermostat would be using AAA batteries.

If it doesn’t this means that the problem might be in the wiring. Wiring is a very delicate aspect of the RV furnace. It delivers necessary power to the ignition switch but most wires are not built to be placed out in the open.

One thing that indicates that your thermostat has a loose or damaged wire is the display. The display should be clear, showing you the temperature that you have set the thermostat at. If the display is off, the batteries are probably dead. Or there is an issue with the wire. Sometimes the display would show you jumbled up numbers or a glitchy screen. This is also a sign of power supply issues. Usually loose wires are what cause your display to go haywire. Lack of a response when you push your button is another sign that the battery might be running low.

Corrosion can be an issue with thermostats as well. Not with the devices themselves, but in the wiring that connects them to your RV furnace. Corrosion in wires is a much more serious issue. They can be difficult to clean since they always have live electrical currents going through them. Touching a live wire with anything wet will cause electrocution.

We’re not talking about the comical sort of electrocution that you might have seen in cartoons, either. This is serious electrocution that has the potential to cause death. Whenever you work with anything electrical, remember to take adequate safety precautions. There’s no point in fixing your RV furnace if you’re not around to enjoy using it. Disconnect the thermostat wire from all electrical outlets so that you can clean the corrosion safely.

Your thermostat is not going to start working again immediately, by the way. It would need a bit of time to reset. Whenever you restart your thermostat, it would take a couple of minutes to start functioning properly again. This is because the program needs to restart. You might have to input all of your temperature preferences and the like once again so that the RV furnace can work according to your specifications. This process shouldn’t take longer than a couple of minutes, though. If it does, this means that the thermostat has other issues that you might need to deal with.

How to Handle a RV Furnace That Doesn’t Work After Ignition

Sometimes the problem with your RV furnace is not going to be quite so obvious. In fact, the ignition might even be turning on. But your RV furnace would still fail to provide adequate heat. This is a slightly more serious issue. It indicates that the problem would not be so easily solved. Don’t be daunted by this, though. Where there is a will there is always a way. There are three or four things that could be wrong with your RV furnace if it doesn’t heat your RV up even after it has been ignited.

Pilot Light Issues

The purpose of the ignition spark is to turn on the pilot flame. This flame is what will warm up water for you as well as provide heat that you would need during winter. The pilot light is what will light the larger flame that your RV furnace would use. A spark usually isn’t hot enough to light an entire RV furnace after all. It’s a stepping stone that turns the pilot light on, and it’s the pilot light that does the rest of the heavy lifting from there. Check to see if a spark is happening when you try to turn the RV furnace on. If the RV furnace is sparking but the pilot light is either not turning on or is too low to be of any use, you might have a problem with ventilation.

Check to see if any of the exhaust vents have debris or soot in them. This soot can block air flow from coming into the RV furnace. Fire needs oxygen in order to burn. If there’s not enough ventilation in your RV furnace, the pilot light would not have the oxygen it needs to burn as brightly and as hotly as possible. Clean your RV furnace out every few weeks so that a buildup doesn’t occur.

Damaged or Faulty Thermocouple

The thermocouple is a safety feature that is essential to any RV furnace. It works as a sensor that detects whether or not the pilot flame is on. If the pilot flame isn’t on, the thermocouple would not allow propane to end up flowing into the RV furnace. Hence, the pilot flame would immediately go out since it wouldn’t have any fuel that it can ignite. A pilot flame that goes out as soon as you let go of the ignition button indicates that the thermocouple is faulty. Because the pilot flame is on, the thermocouple should automatically start releasing propane. If it doesn’t do this there’s probably something wrong with it. Try to listen for a click when the pilot flame goes off. The click is the biggest sign that there is something wrong with your thermocouple.

Usually if a thermocouple isn’t working it’s just because it’s dirty. Cobwebs and debris can prevent it from detecting the pilot flame. Giving it a good dusting should make it work, but if it doesn’t then you should just get it replaced. Thermocouples are really cheap so don’t hesitate to get a new one. They need to be replaced every so often anyway so this would be a smart move on your part.

Blower Fan Problems

Sometimes when you turn your RV furnace on, it would provide a little bit of heat. It just won’t be nearly as much heat as you were expecting. The RV furnace would still be usable if this is the case. You would just need to make sure that you turn it on well in advance. This can be inconvenient though, so you should still try to get to the bottom of the issue. Improper heat distribution in spite of the pilot flame working fine is a sign that your furnace blower fan has been damaged or is starting to fail.

First check if the furnace blower fan is hot. The RV furnace is supposed to be getting hot, not the blower fan. Heat emanating from the blower fan usually comes from overloaded internal wiring. Trying to take care of this issue is important if you want it to start working again. Check if any of the wires are loose. Otherwise take the blower apart and see if any of the internal wiring has melted. If this has happened, don’t bother with trying to repair the fan. This would be time consuming and ineffective. Instead, just get it replaced. Just like thermocouples, blower fans are not that expensive to replace.

Problematic Sail Switch

This is a part of the RV furnace that most people might not be familiar with. It has a similar role to that of the thermostat. However, it doesn’t detect the pilot flame. Instead, it detects airflow. If the RV furnace turns on without adequate ventilation, firstly it might not start at all. If it does start, there would be an internal buildup of gas which would potentially lead to a really serious explosion. Or it could just damage your furnace which is just as bad.

Your sail switch might be unable to detect airflow because it hasn’t been cleaned in a while. The blower might not work when this happens, so take this into account when you are checking the blower fan too. Clearing soot or other debris from the sail switch should take care of this issue. Check the ignition before checking the sail switch, though. Ignition issues are more common than sail switch issues. Unless you don’t regularly clean your furnace.

Keeping Warm If Your Furnace Won’t Ignite

When all else fails, you are going to be stuck without a furnace. Your only option here would be to call a professional. Said professional would know just what to do in order to get your furnace up and running again. Alternatively, they might be able to tell you decisively that your furnace is not going to start back up again and you would be better off getting a new one. The only problem with this is that no expert is going to come over immediately. At best you can expect them in a few hours, and if you call at night then it would take them about a day to come to you since they probably have other clients.

While you are tuck in this limbo where your furnace isn’t working and you have a whole night to spend without it, this doesn’t change the fact that you need to keep warm. Luckily, there are a few things that you can do to keep warm when your furnace isn’t working. We have some tips for you that would allow you to stay cozy. Bear in mind that none of these tips are a replacement for a good furnace. They are just stopgap solutions that can tide you over until your furnace starts working again.

Keeping warm is also important if you are hoping to fix the furnace. When the heat isn’t on, your hands would get really cold and numb. You would lose feeling in your hands which could lead to you not being able to handle any of the tasks that are required. Warming up before trying to figure out what’s wrong with your furnace is essential. These tips will help you with that, thereby making it easier for you to fix the issue in the first place. Without further ado, here are some handy tips that you can use to keep warm when your furnace fails to work properly.

Use The RVs Vent Heaters

Most RVs come with heaters. They are generally meant to be used while driving. However, if you are stuck in a situation where your furnace isn’t working, they might just be your only heating option. You can’t leave them on all night though. This might kill the battery of your car. By the way, this really isn’t a very effective heating solution. The heaters in RVs are not built to distribute heat across large surfaces. They are only meant to provide heat up to a few feet away from the vents. So don’t think that you can just switch to using these heaters if your furnace stops working. Getting it fixed is absolutely essential since this is not a long term heating solution.

Get a Space Heater

If you’re planning to travel in an RV, you most definitely need to buy a space heater. Even if your furnace is working perfectly, a space heater is a handy tool to have. It’s when your furnace stops working that a space heater would prove its true usefulness. They provide some excellent heat. So much so that your RV would warm up in no time. The only reason why you can’t use them permanently is because it can be a bit dangerous.

Leaving the heater on can make your RV fill up with toxic gas. This would cause suffocation among other serious problems. Another danger associated with using space heaters is that they could fall over. If this happens while you are asleep then there would be nobody around to pick the heater back up again. As a result, anything flammable that’s near the heater could catch fire. This fire would spread very quickly, so only buy space heaters that have an automatic shutoff feature. What’s more is that space heaters can’t heat up water for you to use. So you should definitely only use them as a temporary solution.

Bundle Up And Cuddle

It’s time to take out all of your blankets, quilts and jackets. Bundle up as much as possible because hypothermia is a very real, and very dangerous, thing. You should also try to stay close to the other people in the RV. Human bodies produce quite a bit of heat. If all of you cuddle up close to each other, this could provide enough heat to keep everyone reasonably comfortable. It’s a great way to boost morale during a difficult time as well. Physical proximity creates feelings of intimacy and affection. Both of which are great things to rely on when one of your basic necessities isn’t working the way that it should.

Use Candles

Candles are a great source of illumination. Your furnace not turning on could be as a result of issues in your electrical system. This would mean that none of your lights would turn on either. By using candles, you can provide some much needed brightness. Candles also provide a lot of warmth. If you light enough of them, you will generate a fair amount of warmth. This warmth would be further compounded if your RV has been properly insulated. Good insulation is an important investment. It would be a big help if you are ever in a situation where your furnace isn’t working. Because with good insulation even the most basic heating solutions can go a long way and your furnace would probably end up working a lot more efficiently as well.

Start a Bonfire

Going outside when it’s so cold might sound strange. However, if your furnace isn’t working it might actually be a good idea. After all, it’s not like the interior of your RV is providing any kind of warmth. If you go outside you can light a bonfire. A large enough bonfire would provide more than enough warmth for everyone to use. It can also help create a fun filled environment for all to enjoy. You can use this to further bond with the people who are traveling alongside you. Bonfires give you the chance to contemplate about things and they can be a welcome break from the breakneck pace of day to day life.

Bonfires have a lot of other uses as well. For example, you could buy heating bricks and place them on the fire after wrapping them in tin foil or aluminum foil. Once the bricks are hot enough, you could bring them inside and place them in a safe location. They would emanate a lot of heat which you can use to keep yourself cozy. Or you could just sit by the fire and enjoy the ample warmth that it can provide too.

Keep Spare Propane Tanks And Batteries

Propane supply issues and electrical supply problems are the most common causes of furnace failure. Keeping a spare propane tank means that if one runs out you can replace it immediately and start your furnace back up again. The same goes for having a spare battery on hand.

Do Some Physical Activity

Go for a short run and when you come back you will be a lot warmer than you were before. In fact, you might even want to take your jacket off although we recommend that you don’t do this since it will cause hypothermia. Being as active as possible can warm you up. This warmth will also last a very long time. If your furnace stops working during the day, why not play a football game with the other people in your RV? This would get everyone warmed up after which the lack of a furnace would no longer be so much of an issue. It will help tide everyone over until the person you have called for repairs comes along.

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