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How to Fix an RV Furnace That Won’t Stay Lit

As an RV owner, ensuring your vehicle is cozy and warm, especially during colder months, is crucial. But, what happens when your RV furnace won't stay lit?  This can turn…

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As an RV owner, ensuring your vehicle is cozy and warm, especially during colder months, is crucial. But, what happens when your RV furnace won’t stay lit? 

This can turn your comfortable RV into a chilly nightmare. But worry not. Understanding the underlying causes and knowing how to fix them can alleviate this issue, and that’s what this guide is all about. 

We will delve into the causes and solutions to an RV furnace that won’t stay lit, providing you with the necessary knowledge to keep your mobile home toasty.

How Does Your RV Furnace Works?

Before diving into the troubleshooting, it’s important to grasp the basic workings of your RV furnace. At its core, an RV furnace operates similarly to a home furnace, just on a smaller scale. When you adjust your thermostat to a desired temperature, it sends a signal to the furnace.

The furnace’s control board then opens the gas valve and ignites the burner. Once the burner is lit, the furnace’s blower starts to circulate warm air throughout your RV via the duct system. An important component to note here is the sail switch, which confirms that the blower is working before the gas is ignited to prevent unburned gas from being released.

If everything is working correctly, your furnace stays lit until the interior of your RV reaches the set temperature. However, if your “RV furnace won’t stay lit,” it could be due to a range of issues, which we’ll explore in the next section.

READ: How to Fix Payne Furnace Codes 4 Flashes

Common Reasons Why an RV Furnace Won’t Stay Lit

There could be several reasons why your RV furnace won’t stay lit. Here are some of the most common:

1. Dirty or Damaged Thermocouple: The thermocouple is a safety device that senses when the burner is lit and keeps the gas line open. If it’s dirty or damaged, it may not sense the flame, causing the gas valve to close.

2. Insufficient Gas Pressure: If the pressure in your propane tank is too low, it may not be able to feed enough gas to keep the burner lit.

3. Faulty Gas Valve: A malfunctioning gas valve may not stay open, even if the thermocouple is functioning properly, interrupting the gas supply to the burner.

4. Blocked Exhaust Vents: If the furnace’s exhaust vents are blocked, it can cause the burner to go out due to a lack of oxygen.

5. Faulty Control Board: The control board regulates the sequence of operations within the furnace. If it’s defective, it could lead to a variety of issues, including a furnace that won’t stay lit.

6. Bad Thermostat: Sometimes, the problem could be as simple as a malfunctioning thermostat that’s not sending the right signals to your furnace.

How to Fix an RV Furnace That Won’t Stay Lit

This can be a frustrating and inconvenient problem, especially in cold weather. There are several possible causes and solutions for this issue, depending on the type and model of your furnace. Here are some steps that you can follow to troubleshoot and fix your RV furnace that won’t stay lit:

Step 1: Check the propane level and pressure 

If your propane tank is low or empty, your furnace won’t be able to ignite or stay lit. You can check the propane level by looking at the gauge on the tank or using a propane level indicator. 

You can also check the propane pressure by using a manometer or a pressure gauge. The ideal pressure for most RV furnaces is between 11 and 13 inches of water column (WC). If the pressure is too low or too high, it can affect the performance of your furnace. You may need to adjust the regulator on the tank or replace it if it is faulty. But it’s recommended to have a professional check your system’s gas pressure.

Step 2: Check the battery voltage and connections 

If your battery is weak or dead, your furnace won’t be able to ignite or stay lit. You can check the battery voltage by using a multimeter or a voltmeter. The ideal voltage for most RV furnaces is between 10.5 and 13.5 volts DC. If the voltage is too low or too high, it can affect the performance of your furnace. You may need to charge or replace your battery if it is weak or dead. You should also check the battery connections and make sure they are clean and tight. Loose or corroded connections can cause intermittent or no power to your furnace.

Step 3: Check the thermostat and wiring 

If your thermostat is faulty or misadjusted, your furnace won’t be able to ignite or stay lit. You can check the thermostat by setting it to a higher temperature than the ambient temperature and listening for a click sound. 

If you don’t hear a click sound, your thermostat may be faulty or misadjusted. You may need to replace or recalibrate your thermostat if it is faulty or misadjusted. You should also check the wiring between the thermostat and the furnace and make sure they are not damaged or loose. Damaged or loose wiring can cause irregular or no signal to your furnace.

Also, you can inspect the Thermocouple: If the thermocouple is dirty, clean it gently with a soft cloth or a small brush. If it’s damaged, it will need to be replaced.

Step 4: Check the sail switch and limit switch

If your sail switch or limit switch is faulty or stuck, your furnace won’t be able to ignite or stay lit. The sail switch is a device that detects the airflow from the blower fan and sends a signal to the circuit board to start the ignition process. 

The limit switch is a device that monitors the temperature inside the heat exchanger and shuts off the gas valve if it gets too hot. You can check the sail switch and limit switch by using a multimeter or an ohmmeter and testing for continuity. If you don’t get continuity, your sail switch or limit switch may be faulty or stuck. You may need to replace or reset your sail switch or limit switch if they are faulty or stuck.

Step 5: Check the igniter, electrode, burner, and flame sensor

If your igniter, electrode, burner, or flame sensor is dirty, damaged, misaligned, or worn out, your furnace won’t be able to ignite or stay lit. The igniter is a device that creates a spark to light the gas mixture in the burner. 

The electrode is a metal rod that carries the spark from the igniter to the burner. The burner is a device that mixes air and gas and produces a flame for heating. The flame sensor is a device that detects the presence of a flame and sends a signal to the circuit board to keep the gas valve open. 

You can check the igniter, electrode, burner, and flame sensor by inspecting them visually and cleaning them with compressed air or a soft brush. If you see any signs of dirt, damage, misalignment, or wear, you may need to replace them.

Clear the Exhaust Vents: Make sure the exhaust vents are clear of any debris or blockages that could prevent proper ventilation. Always switch off the furnace before doing this.

Inspect the Control Board: Look for any signs of damage or faulty wiring. If you suspect the control board is defective, consider hiring a professional to replace it.

These are some of the common steps that you can follow to troubleshoot and fix your RV furnace that won’t stay lit. However, there may be other factors that affect your furnace performance, such as altitude, humidity, wind, venting, etc. 

Remember, while it’s helpful to understand these common issues and potential solutions, always prioritize safety. If you’re not confident in performing these checks or repairs yourself, it’s best to hire a professional.

READ: How to Troubleshoot Common Issues with Your Amana S-series HVAC System

Safety Precautions When Fixing an RV Furnace

Working on an RV furnace, especially when it involves gas and electricity, can be risky if you don’t take the right precautions. Here are some safety tips to keep in mind:

1. Power Off: Always switch off the power to your furnace before starting any work. This can help prevent electrical shocks.

2. Use the Correct Tools: Always use the correct tools for the task at hand. They should be in good condition and suitable for the job.

3. Wear Protective Gear: Safety glasses, gloves, and other protective gear can protect you from potential harm.

4. Follow Instructions: Always follow the manufacturer’s instructions or your RV manual when working on your furnace. If you can’t find the answer in these resources, it’s best to seek professional help.

5. Don’t Force Anything: If a component doesn’t fit or a screw doesn’t turn, don’t force it. This could lead to further damage or risk of injury.

6. Ventilate the Area: Ensure the area is well-ventilated, especially when you’re working with gas.

7. If in Doubt, Call a Professional: If you’re unsure about anything or feel uncomfortable at any point, it’s safest to call a professional.

READ: The Ultimate Guide to Goodman Furnace Problems

Conclusion

Tackling an issue like an RV furnace that won’t stay lit can be daunting, but with the right understanding and tools, it can often be manageable. In this guide, we’ve walked you through the basics of how your furnace works, explained common causes of this problem, and provided a step-by-step guide to troubleshooting. We’ve also highlighted the importance of safety when undertaking these tasks.

However, never forget the value of professional help. If you’re unsure at any point, don’t hesitate to call in a professional to ensure the job is done safely and correctly. Remember, taking care of your RV furnace ensures a comfortable and warm journey, no matter where the road takes you.

HVAC aficionado, keeping temperatures just right and comfort levels off the charts. Connect with me on LinkedIn for cooling insights and follow me on Twitter for heating up the HVAC conversation. Let's create the perfect climate together!

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Hi there, I'm Robert Brooks

Hi there, I'm Robert Brooks

I’m so glad you are here! Welcome to my website, where I’ll share easiest HVAC troubleshooting tips, buyers guides, and everything about HVAC cooling and heating system. Learn more about me.

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