11 Most common RV Furnace problems and how to fix them - Camper Grid (2023)

Rv furnace problems are very common and finding a solution to that problem is easy if you troubleshoot it step by step. In this article, we will see common RV furnace issues and how to get them resolved.

A preventive maintenance can really help in keeping the furnace in good working condition. A newly installed furnace can also face issues in which case its easy to get it replaced under warranty.

A working of furnace will vary depending on the type and model. In most cases, its a standard functioning though. Lets check out the furnace problems and how to fix them.

1. RV furnace Is Not Igniting

This is a common problem with furnaces in RV. When the temperature is going down, its snowing and everything is freezing, you don’t want your furnace to have this issue. Lets check how to troubleshoot this problem.

Issue With Propane Tank Gas Lines

It will be possible to diagnose any malfunctioning on the part of the propane gas or tank lines by assessing whether any gas is obtainable.

This can be done by setting a 2-way refrigerator to the propane, turning on the propane range which works internally, or igniting other appliances running out the identical gas line.

In case it does work, you can be certain that the propane tank is not responsible for this. In case no evidence of any gas is found within the system, it will be imperative to check the system thoroughly beginning with the tank.

Tackling an issue with gas lines or a propane tank

During winter, the metal is going to contract, and therefore, it is possible for a propane coupler to become loose.

Make it a point to verify that everything is quite tight. In case there would have been any leakage in the internal line which is running via the RV, you could be getting rotten egg smells.

In case, there is any leakage on the mainline, you will find it difficult to identify it simply by smelling. If feasible, let your hand run along the line while trying to feel any areas which have been either damaged or cracked.

Ensure to verify what exactly the propane line is going to enter inside the body of the camper. On some occasions, the gaskets might wear on a hose leading to a minor leakage.

It might be possible for you to use duct tape for wrapping a small leakage. Although it might work, it will not be able to fix the problem permanently.

Ignition Failure

On the majority of the RV propane furnaces, the igniter requires a minimum of 10.5 V for firing properly.

In case a couple of the onboard batteries has become compromised or have run quite low, there might not be enough spark for operating the thermostat or igniting the system.

At times, it is all about the tripping of the circuit breaker. Consequently, the panel should be checked for making certain that every single breaker for the thermostat and the furnace is switched on.

Next, let us see some more common RV furnace issues and how to fix them.

Failure of electricity within the propane system

If it is possible, try to use a backup battery which is able to produce in excess of 10 V.

Being disparate, you might be using the 12 V battery from the tow vehicle or the motorhome although this will be your “Last Ditch” effort. You never like to end up with a dead battery in the long run.

A wiring issue might not allow the electricity to ignite the surface

In case the onboard batteries indicate that they are supplying adequate power to the device, then you can test to see if the issue is due to a broken or loose wire. While monitoring wires this needs a careful approach.

Starting at the furnace itself could be helpful. Verify repeatedly all the connections as well as wires in it. On some occasions, the vibration caused by driving can cause a wire to become loose, or a connector might even fall out.

A wire may even get overloaded or it might also damage the protective coating.

Figuring out whether it is an issue caused by electricity

On the majority of the RV propane furnaces, the igniter typically requires a minimum of 10.5 Volts for firing properly. If a couple of the onboard batteries have run critically low or is corrupted, there might not be enough fuel for the device to ignite or the thermostat to function.

Occasionally, it’s just an issue of tripping a circuit breaker. Consequently, test the panel to guarantee that the furnace and thermostat breakers happen to be “On”.

An onboard battery which is dead or low

A simple multimeter test will inform you of the number of volts the furnace is equipped with. In case it is less at 10 V then one of the onboard batteries is likely to be the issue.

Without adequate electricity being supplied to the furnace or the thermostat, it might not be able to fire, and the fan may or may not work at all.

Consider swapping to a backup battery which can generate in excess of 10 Volts, if feasible. You may be capable of using the 12 Volt battery from the tow vehicle or motorhome in a moment of panic; however, it’s a kind of “Last Ditch” matter. You’d never like to end up with a dead battery as well.

Corrosion of the battery

Look closely at the connectors and the battery terminals. Electrolytic corrosion might lead to the development of a gray, white, or greenish material on a terminal over time.

Left unattended it can prevent the furnace system from getting electricity. A quick cleaning is often all that is required for re-establishing an effectual connection.

Corroded battery terminals

Cleaning them properly can help solve this problem. Lets see the steps we need to follow for this.

  • Prepare a slurry blend of water and baking soda.
  • Disconnect carefully the wires and the connections from the terminal which is corroded.
  • Make use of a toothbrush for applying the baking soda mixture and scrub the corroded material carefully.
  • Wipe the baking soda off comprehensively by making use of a clean paper towel.
  • After reconnecting the cables to the terminal, verify to ensure that the internal lights of the RV, the furnace, and the thermostat are receiving power.

A problem with wiring might not allow electricity to ignite the furnace

In case the onboard batteries indicate that they supply adequate power to the device, then you can test to see if the issue is due to a broken or loose wire. This needs a careful approach while monitoring wires.

It might be a good idea to begin at the furnace on its own. Check repeatedly all the connections as well as wires. At times the vibration caused by driving can cause a wire to become loose, or a connector might even fall out.

A wire might even get overloaded or the protective layer can become damaged.

A Faulty Wire

In case the situation is not improved by this, it will be imperative for you to verify for any loose connection or cables between the ignition system of the furnace and the battery.

At times even anything as basic as the corrosion of the terminal of the battery will impede the efficient distribution of the required electricity.

In case a connection or cable becomes loose, it will be imperative on your part to make it tight or perhaps strip, clip, and protect it using a wire nut. A broken cable might be required to be spliced, patched, or even replaced whatsoever.

In case the battery terminals become corroded, it might be possible to get the required power from the connection by cleaning them using a mixture of baking soda and water and then using an old toothbrush for scrubbing it.

Damaged section of the cable

Lets see the steps to replace a cable.

  • Snip out the section which has been damaged by making use of a wire cutter.
  • Cautiously strip one inch of protective layer back on the two exposed wire sections.
  • Take a fresh piece of wire which is similar to or perhaps thicker gauge and then strip the protective layer at each end by 1 inch.
  • Braid together the ends of the cable which are exposed. Following this, they can be soldered and wrapped using electrical tape or you can even twist them safely within a wire nut.

Thermostat Issue

The “brain” of the cooling and heating system is actually the thermostat. Although they are intended to last a long time, burning out or making a part to malfunction is not unheard of.

In the majority of these cases, it will be imperative for the entire unit to be replaced given that the sensor is going to die.

Nevertheless, on some occasions, something such as a dead battery or a loose cable might result in the malfunctioning of the thermostat. Once this takes place, the message for igniting the furnace will not be sent and no gas will be delivered by the safety systems within the furnace.

Loose Cable On The Thermostat

In case the thermostat has got a digital display panel which is blinking, it might be because of a loose cable.

You have to remove the cable from the wall carefully for checking this. Some are fixed by small screws that might fall out and you might need to make them tight once again.

Verifying and replacing thermostat batteries

The thermostat is not connected to the onboard batteries in some RVs. These units are usually powered by AA batteries.

In the majority of these cases, the display screen is going to blink or it might also provide you with a blank screen. In such cases, replacing the batteries will be a sensible idea. While doing this verify whether the connections are corroded.

Following this, switch on the thermostat and allow it to reset the internal program. In case it is a problem related to low battery, the thermostat will begin to function normally while the furnace should be firing once again.

2. RV Furnace makes noise

Any of your RV appliances making noise is disturbing. Most of the times it will not be your furnace but its the furnace then be sure something is right with it. Turning it off is definitely an option but it wont fix the problem when you want it next time.

To get to the root cause the type of noise is an important thing to notice. The first thing that we do is to make sure clean it. Regular maintenance specially at the end of the summer season is what normal we follow.

Even small dirt or debris can cause the obstruction in the furnace which can lead to reduced efficiency and noise.

Make sure you are cleaning all the accessible parts or components to keep it running smoothly. Make use of wire brush to clean the dust over its components.

Wippign off fan balds during the maintenance is also recommended. Vaccum all the possibel areas isnide. Cleanig is definaetly a way to maintain the furnace but it may not immedietly reduce the nosie.

Other cause here could be loosen screws or other hardware. Make sure all the screws are tight enough and anything hat is lose is tightened. Other things to look at include duct inspection and repairs, cleaning the fan, and checking on igniter lines.

3. Reduced air flow

This can be due to distribution hose becoming loose or detaching from the connection. The ducts can be long enough and there could be some form of obstruction that’s causing the low air flow. Removing the excess duct can be one solution if you encounter the problem initially.

See if there is adjustable flow in case if your furnace. If its there then do check and adjust it accordingly.

The fan or the blower in furnace could have become old resulting in low air flow. Or it could have become weak due either due to more use or obviously due to quality. One of our friends travel trailer Dometic furnace had this issue but they couldn’t get it fixed. It was later replaced by the company.

4. RV Furnace Keep Cycling On And Off

Furnaces are designed to make sure they are turned off once the temperature is reached. Later if the temperature falls it would again turn itself on to get the thermostat set temperature.

If the furnace keeps cycling on and off despite the temperature meeting then there is some problem with the furnace functioning. This can be caused if the furnace vents are blocked.

Check for the furnace box, see if there is anything that is blocking the furnace vents. Any obstruction in the vents will result in malfunctioning and heating of the furnace.

This will lead the temperature limiting switch to turn off the furnace. Vents can blocked due to various things, debris dust can also block it. Make sure you are doing preventive maintenance as per schedule.

5. RV furnace keeps tripping reset button

This is common issue with new purchases. We have seen this happening when the furnace reset button would trips suddenly. If the furnaces was installed recently check with the company support.

They should come and have a check. The most common reason why this would happen is again the heating problem. The duct would be blocked or is long enough.

The vent could be collapsed or here could be issue with the circuit board. Many a times the furnaces come with such issues, the companies guys know that and they would see if it get through. You would get the replacement if the issue isn’t resolved.

6. RV furnace does not stay lit

This is the ultimate result of other issues that can be with the whole furnace system in your RV.

It can happen when you have a bad thermostat. Make sure the thermostat is is fine working condition. A low propane pressure at the furnace ca also result in furnace not lighting.

7. RV furnace keeps turning off

This could be an issue with the limit switch. Most common story with many goes like this, initially the furnace would turn on, go on till the temperature are met according to the thermostat.

Then turn off the furnace and later as the temperature falls it could not turn on again. This happens if the furnace is in locked out sate.

The issue could be with the control board which wouldn’t respond to the lighting signal.

In most cases the control board need to be replaced. If you are in warranty then the company would replace it. We have seen such a issue with our suburban furnace last year.

8. Furnace shuts off after 30 seconds

This again is seen by many new RV furnace buyers. A couple friend of ours had this issue with their Atwood furnace where in the furnace would turn on and then shut of in like 20-30 seconds. And this was happening every-time.

The problem in this case is with the blocked vents of the furnace. The temperature limiting switch shuts off the burner when high temperature are reached. In this case it happens very fast.

For this make sure the vents are cleared and there is no blockage. The air flow could be limited due t the obstruction. There could also be possibility of having a bad temperature limiting switch.

If even after clearing the vents the issue is not resolved then do check with the company or technician.

9. Furnace turns on but no heat

This issue or if the furnace is blowing cold air could be due to the circuit board issue or the limit switch issue. As a first step you may want to clean the combustion area. Clean all the debris or spiders.

See of the cleaning dies the trick. If it does not then take help from the technician. n mist cases its the circuit board. A bad propane tank regulator can also result in this issue.

The internal furnace switch wont let the furnace ignite resulting in less heat. So, you will have the fan running but thee wont be any heat or less heat.

10. RV furnace clicks but won’t start

The furnace may make a click sound but it wont start. This happens when the spark igniter try’s to ignite the pilot light but fails. This is nothing but a ignition system failure.

This has to be fixed and its a good idea to take technical help here. If the furnace is in warranty then you will get it replaced. But, normally the furnace would be too old when this problem occurs unless its a manufacturer fault.

11. RV furnace cycles on and off

This could be the result of blocked vents on the furnace or any other obstruction caused. Either ways make sure you take it on priority as otherwise it can result in heating problems.

This can also cause carbon monoxide generation. The exhaust on the furnace can be blocked by various things. Makes sure you clear it out and make sway for air flow.

The RV thermostat itself could have gone bad resulting in control cycling on and off. If its the thermostat then you can get it replaced, they are less costly to replace.

In Conclusion

Riving in winter is fun and adventurer but a malfunctioning furnace will make it worse. You definitely don’t want to be there in the middle with a non working furnace. Keeping yourself warm is keeping yourself comfortable.

Do take out some time after the summer season to do the basic preventive maintenance. If you have installed a new furnace then try it out multiple items before heading for a camping trip with heavy snow and chilling cold.

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