/ / / RV Furnace Clicking But Not Lighting: Troubleshooting Giude How to Fix the Issue

RV Furnace Clicking But Not Lighting: Troubleshooting Giude How to Fix the Issue

Does the RV furnace clicking but not lighting sound familiar? Don’t worry, this is a common problem in vehicles. You turn your device on and hear the blower running, but it never lights, and then the blower eventually turns off.

This does not mean you need a new furnace since you can fix the problem yourself. I have experienced it several times on my RVing adventures so will help you to troubleshoot the issue.

In this article, I will look at how RV furnaces work, the reasons for the furnace sparking but not lighting, and ways of solving the problem. Join me, and let’s start learning!

RV Furnace Clicking But Not Lighting: 10 Easy Fixes Listed!

How Does an RV Furnace Work?

An RV propane furnace is a forced-hot-air system that uses a propane supply or electricity and several furnace components to function. Here is a step-by-step process of how this furnace works:

  • Thermostat Activation: Whenever the thermostat detects temperatures lower than the initially set point, it signals the furnace to begin working.
  • Blower Motor Activation: The blower motor will initiate and run for about 15 to 30 seconds to eliminate any combustible materials from the combustion chamber.
  • Sail Switch Engagement: The furnace fan will then activate the sail switch, which signals the release of propane into the combustion chamber.
  • Ignition: An electric ignitor generates a spark, which ignites the propane in the burn chamber and a flame sensor will detect flames in the chamber.
  • Heat Generation: The furnace then heats up, and if the temperature level remains within limits, it will continue operating.
  • High Limit Switch: When temperatures become too high, the high switch limit will be triggered, which cuts off the fuel supply to ensure safety.
  • Propane Supply: The regulator will supply a consistent flow of propane or electricity if there is enough power or gas supply.
  • Heat Exchanger Operation: The heat exchanger on the furnace warms the air while the RV furnace blower fan circulates the hot air throughout the RV.
  • Thermostat Shutdown Signal: When the thermostat attains the desired temperature, it signals the shutting off of the furnace and enters the “cool down” cycle. During this cycle, the blower fan continues running but will be blowing cold air.
  • Electricity or Propane Cut-Off: The furnace stops the electricity or gas supply and goes into a shutdown mode.

Note: This entire process will repeat when the thermostat signals for additional heat.

Reasons Why RV Furnace Clicking But Not Lighting 

I’ve found myself shivering in my RV despite the furnace being turned on, and I know the frustrations of a furnace that clicks but doesn’t ignite. Identifying the exact problem is easy if you know whether your furnace uses gas or electricity. Some of the reasons why an camping vehicle’s furnace may not light include the following:

  • Inadequate power supply;
  • Faulty propane tanks or lines;
  • Electrical wiring issues;
  • Burned thermocouple;
  • Airflow issues due to propane pressure lock failure;
  • A malfunctioning relay for the Blower Motor;
  • Sail switch failure;
  • Bad gas valve;
  • Ignitor failure;
  • Damaged control board;
  • Dirty or blocked outside exhaust vent;
  • Incomplete combustion;
  • Dirty or clogged air return grill;
  • Broken or misaligned metal arms.

When the RV furnace doesn’t light, your recreational vehicle will automatically turn it off as a safety measure. You can usually troubleshoot and fix the issue without taking the RV to the repair shop. Keep reading as I take you through everything you need to know about your RV furnace clicking but still not lighting.

Ricky Smalls
An RV furnace’s clicking without lighting can be quite frustrating, but it’s often a solvable problem. Think of it as your RV’s way of saying, ‘I need your attention.’ A systematic approach to troubleshooting will ensure you have your warm haven again.Ricky Smalls

Troubleshooting RV Furnace Problems

There could be several reasons your RV furnace isn’t producing heat whenever you turn up the thermostat. Let’s quickly look at the common causes and how to troubleshoot them:

1. Check the Power Button

RV furnaces powered by electricity or a propane supply will both have a power switch. Therefore, when experiencing issues with my furnace, the first step I take is to ensure this power button is switched on.

In addition, I also analyzed the breaker to confirm if the furnace’s power had tripped, and reassembled it. However, if I notice the tripping persists after reassembling, I always call a professional to examine my furnace.

2. Check If You Have Adequate Gas or Battery Power

I discovered that my RV furnace will only ignite if it’s getting adequate electrical power or propane gas supply. For a gas furnace, I always ensure there is plenty of gas inside the tank and refill it if it’s empty. In addition, I make sure the propane tank valve is also open, and if it’s closed, I open it and wait for a few minutes before starting the furnace again.

Check If You Have Adequate Gas or Battery Power
Credit: www.youtube.com @Eddie At Large

Like mine, most electrical furnaces require a 10.5 V power supply to run efficiently. I use a multimeter to look at the output of my RV battery and determine whether the furnace is getting adequate voltage to ignite. Whenever necessary, I substitute the battery and attempt to ignite the furnace again.

3. Check the Thermostat

When using my RV, I set my thermostat at a higher temperature compared to the ambient temperature. Usually, some furnace or flame sensors must detect a lower temperature before turning on the furnace. I switch on the furnace blower to force the furnace to generate heat.

Check the Thermostat
Credit: www.youtube.com @Oliver Travel Trailers

Note: For RVs that have a smart electric furnace with its display, you can look for an error code or confirm if it offers necessary information regarding the furnace problem you are experiencing. Following the product manual will help you to quickly resolve this problem through the error code.

4. Check the Gas Line

In my experience with RV gas furnaces, consistent gas supply is one major factor that guarantees smooth operation. I always make it a point to confirm my gas line is undamaged and clear, ensuring there is reliable gas flow to the furnace.

If I encounter any signs of potential leaks or gas pressure-related issues, I immediately prioritize safety– evacuating the entire RV and consulting professionals for support.

Important! A distinct gas smell or faint sound may indicate a problem in the gas line, and by being attentive to these cues, you ensure a secure environment.

5. Check for Fuse

Inspecting the fuse is crucial in troubleshooting RV furnace problems. When the fuse is blown, it usually manifests as black smoke between the DC supply and the circuit board. This incident interrupts the RV’s battery supply, causing ignition failure.

Check for Fuse
Credit: www.youtube.com @RV Addict

If you encounter a blown fuse or suspect any fuse issues, your go-to action is replacing it. However, if your fuse is burning out consistently, you should immediately consult an electrician.

Note: This proactive action ensures a comprehensive check of all voltage connections, wires, and furnace components and addresses any underlying issues contributing to the fuse-related problems.

6. Check the Ignitor Itself

One of the common culprits hindering the RV furnace from igniting is the metal arms found inside the ignitor. The camper’s furnace will fail to ignite if these arms are either broken or damaged.

I usually examine the gap existing between the metal arms to ensure it’s not too small or too wide since the gap should be approximately ⅛” an inch. In my experience, if the gap is off, replacing the ignitor is necessary.

Important! If the furnace issue persists, seeking expert assistance is essential. However, if immediate fixing of the problem is not possible, it’s best to keep warm for the night and seek help in the morning.

7. Cold Weather

Facing issues with an RV furnace that refuses to light, especially in the cold weather, is a situation I’ve faced during my RV travels. It’s frustrating when cold temperatures affect the gas flow to the furnace. I’ve discovered that a simple yet effective solution is pouring a small quantity of hot water on the regulator to warm it up and facilitate a smoother gas flow. 

Important! However, you must exercise caution during this process and avoid using boiling water as it can be risky. In addition, after applying hot water, wipe off any excess water with a clean cloth.

It’s a simple solution born out of trial and error, guaranteeing a warmer and more comfortable journey on the road during those pretty cold nights.

8.  Check Vents

Experiencing issues with my camper furnace has taught me to consider different factors, and one common problem is blocked air vents. Several instances have occurred, especially after leaving my RV in storage, where these vents were clogged. So, it’s now my routine to check these vents whenever the furnace is not working.

Check Vents
Credit: www.youtube.com @Galipp’s Gadgets

If the vents are blocked, clearing them is all it takes to get my furnace operational again. It’s a lesson I have learned from my RVing experiences, guaranteeing a more enjoyable and smoother experience without issues with the heating system.

9. Sail Switch

Through personal experiences, I’ve learned that if the sail switch is not functioning properly, the furnace will not ignite. The RV sail switch depends on the blower fan to thrust a thin metal piece, completing the electrical circuit and allowing the opening of the propane valve.  However, issues such as pet fur and lint blocking the sail switch may affect this process.

Cleaning the sail switch is usually a quick fix for me; however, there are situations where taking the furnace out for a more thorough analysis becomes necessary. These practical experiences have equipped me to handle sail switch-related issues and ensure my furnace is always running smoothly.

10. Limit Switch

The limit switch is a vigilant protector that senses an overheating situation and quickly trips to prevent mishaps. Even if the switch works, it will eventually shut off after some time. After experiencing this situation a few times, I learned this can happen because of a dirty furnace and blocked ducts.

Since then, my winter rituals have become preventative care and regular cleaning of the furnace and ducks. Although the limit switch was once a mysterious component, it now serves as a reminder of how a little maintenance and attention can ensure a comfortable and uninterrupted RVing adventure.

Best Alternatives for Furnace

Now, I am going to share a couple of the best heaters that will enhance your RV experience even in cold temperatures.

1.  Mr. Portable RV Propane Heater

Mr. Portable RV gas Heater allows you to heat your RV, picnic area, garage, and more with its customized heat settings that range from low, to medium, and high. In addition, it gives off 4,000, 9,000, or 18,000 BTU per hour, and its heat ranges from 450 square feet and can last for 1.8 hours on high and 3.6 hours on low.

2. Xtreme RV Heater

X-treme RV Heater is designed to keep your RVs, cabin, boat, and other small spaces cozy and comfortable. The heater’s 750/1500 Watts heat settings allow you to warm your space and maintain comfortable temperatures quickly.

Overview of People’s Experience with RV Furnace Clicking But Not Lighting

Most RV owners had positive experiences in troubleshooting and solving issues with the RV furnace sparking but not lighting. Below, I will share a few customer reviews:


Macster had an issue with his furnace not lighting; even after several attempts at troubleshooting it, the problem persisted. However, they called RVW, who responded by sending two guys to where they were camping, and the problem was resolved for good.


Hondaman174 also experienced a cold night on one of his RVing adventures when there was a clicking sound from the furnace but no lighting. After calling the dealer to no avail, he accidentally pulled the front cover of the thermostat, revealing another pointer switch, and when he turned it on, the furnace lit again.


Brantime had the same issue of the furnace not restarting and had to solve the problem by resetting the thermostat all the way down and setting it to the desired temperature. He had to learn about issues that can cause the furnace to click without any lighting because they are now living full-time in the RV and have managed to get through lots of cold weather in Colorado Mountain.

Frequently Asked Questions

Why Is My RV Furnace Sparking But Not Lighting?

The sparking is usually caused by the RV’s furnace spark igniter as it attempts to flare up the pilot burners or light. When there is a system malfunction, there will be repetitive Sparking. This can be problematic if you lose heat at some point during the freezing winter months.

Why Is My Furnace Turning On But Not Igniting?

If your gas or electricity furnace initiates the cycle but never fires up, it’s likely because of a dirty or faulty sensor, Inadequate power supply, or a faulty propane tank or line. Additionally, it can be due to airflow issues, damaged gas valves, malfunctioning control boards, sail switch failure, or misaligned or broken metal arms.

Where Can I Find The Furnace Fuse?

The fuse is likely found in the control box closer to the blower for furnaces with a fuse. If you cannot see it, your transformer is likely burnt out and needs replacement. Once you find the fuse, inspect all wires to determine if they are discolored or damaged.

How Long Does A Furnace Last In An RV?

A 20-pound propane tank will power an RV furnace for approximately three hours of uninterrupted operation. However, the furnace does not run continually but only operates for a few minutes, usually every two to three hours, to maintain the temperature.


These are common causes and fixes when your RV furnace clicking but not lighting. If you are comfortable dealing with appliances, you can diagnose or fix the problem yourself. However, you may need to call an RV technician or take your vehicle to the repair shop for professional services.

Knowing the functionalities of your RV will give you the confidence you need to head out on your camping adventures. If you must fix a problem, furnace replacement parts are affordable and widely available. In addition, there is a lot of information available that will give you the knowledge to diagnose and fix problems with your furnace.

Have you ever had your RV furnace clicking and sparking but not lighting? Please share your experiences in the comment section below.

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