Matt Johnson

Uh oh! RV Furnace 15 Amp Fuse Keeps Blowing!

Author: Matt JohnsonPhotos/Graphics: Mike HawthornePublished: Nov 13, 2022Updated: Jan 13, 2024

Few things are more frustrating than when your RV furnace 15 amp fuse keeps blowing. You don’t know whether to blame the furnace or the furnace fuse, and you have yet to learn how to fix it. However, you know you don’t want to be cold when you’re in your camper in the winter.

We will explore the possible causes of a blown RV furnace fuse and offer some solutions. After all, just because it’s winter doesn’t mean you should have to leave the camper in storage!

Potential CauseDescriptionSolution
Short CircuitWires inside the furnace become frayed or damaged and start to touch, causing a spark.Inspect and repair or replace damaged wires.
Faulty WiringIncorrectly installed or damaged wires can prevent an electrical current from surging.Check and correct wiring installation. Replace any damaged wires.
Seized Furnace Blower MotorThe motor may not turn due to old, corroded bearings or obstructions like a nest.Clean and remove any obstructions. If bearings are damaged, the motor may need to be replaced.
Old or Worn-Out FuseThe fuse might have reached the end of its lifecycle.Replace the fuse with a new one of the same amperage.
Loose Wires to the Control BoardLoose connections can cause intermittent power issues leading to fuse blowing.Tighten all connections and ensure proper contact at the control board.
Overloaded Electrical SystemRunning too many appliances simultaneously can overload the system.Reduce the load on the electrical system. Only run essential appliances when the furnace is operating.

What to do if your RV furnace blows a fuse.

You’re enjoying a lovely camping trip, and suddenly, your RV furnace has stopped working. You check the furnace fuse, and sure enough, it has blown.

This is a relatively common issue and is usually an easy fix. While the problem could be the control board or loose wires, the most likely culprit is a blown furnace fuse. Fortunately, fuses are reasonably cheap and easy to replace. This is great because problems with the electrical system are never fun.

Most RVs have between 5 and 15 fuses, so it’s essential to know which controls the furnace. The fuse box will usually be labeled, but if not, consult your owner’s manual. Most importantly, your RV furnace will be on a 15 amp fuse. There might be a few 15 amp fuses mixed in with 10 and 20 amps, but you should be able to find it.

Although they’re usually located in the same panel, these are different than circuit breakers. A breaker is designed to trip and cut off power in the event of an overload. A fuse blows and needs to be replaced. Both are simple enough.

Check both circuit breakers and fuses for your RV furnace to be safe.

If it’s a circuit breaker, simply toggle it back to the on position.

If it’s a fuse, you’ll have to pull the fuse, verify it’s broken, and replace it with another fuse of the same amperage.

Assuming the issue was just a blown fuse, your RV furnace should be working again. If not, there could be another issue at play.

Safety tip: Do not replace your RV fuse with anything other than the amperage recommended by the manufacturer. This could create a fire hazard. So if it’s a 15A fuse, replace it with a 15A fuse and not a 20 amp fuse.

What happens when a furnace fuse blows?

When the 15 amp fuse keeps blowing, the RV furnace will not work. You may see the power to the thermostat, and everything associated with your HVAC systems appears to be functioning. However, the furnace is not turning on.

If you have a new fuse in the panel because you decided to change it out already, go ahead and try to turn on the furnace. If the fuse blows again, you’ll notice a small click or a pop coming from the electrical panel. This is the sound of the fuse physically breaking. You may even see a small flash.

Don’t worry; you should be completely safe. That’s what the fuses are designed for. They’re there to protect your RV from electrical fires.

However, if the furnace blows the fuse on the initial start, this is a sign that there is a more severe problem with your furnace, and you’ll need to have it checked out by a professional.

This is most likely a motor or wiring problem. If you’re handy, take a shot at diagnosing it. Just be careful and take all necessary safety precautions when dealing with loose wires such as turning off the gas line.

Pro tip: Conduct regular inspections of your furnace wiring, especially before the start of each winter season. This can help identify and fix any frayed or damaged wires that might cause short circuits, reducing the risk of fuse blowouts. Mice and other critters will often chew through wiring creating havoc.

Why might the furnace keep blowing fuses?

There could be several reasons for the RV furnace 15A fuse to keep blowing, some more difficult to diagnose and fix than others.

  • Short circuit. Damaged or frayed wires inside the furnace causing sparks.
  • Faulty wiring. Incorrect or damaged installation preventing electrical current flow.
  • Manufacturer error. Unchecked wiring in new campers or RVs with potential loose wires.
  • Seized furnace blower motor. Due to old, corroded bearings or obstruction from debris like a mouse nest.

A short circuit is one of the most common reasons RV furnaces break fuses. This typically happens when the wires inside the furnace become frayed or damaged and start to touch. This can cause a spark and, ultimately, a fire. That’s why it’s so important to have a working fuse.

Another reason for blown fuses is faulty wiring. If the wires are incorrectly installed or damaged, they can prevent an electrical current from surging. This can also lead to a fire, so having this fixed as soon as possible is essential.

Don’t think that a new camper or RV is without its flaws. The manufacturer might have not checked the wiring and there may be some loose wires to the control board. If it is a newer RV, chances are you’re under warranty anyways.

Finally, another possibility is that the furnace blower motor is seized.

For whatever reason, it will not turn. This might be because the bearings are old, corroded, and seized up or because a mouse has built a nest in the motor, and the debris has stopped it from turning.

Regardless, a furnace motor that won’t turn is a serious problem that will need to be fixed, or you’ll continue to pop fuses. You may need a new motor or new unit altogether.

Fixing the problem and preventing fuses from blowing.

Now that you have a good idea of how to identify the problem let’s discuss fixing the problem.

  1. Replace old fuse. Start by replacing the old fuse with a new one to see if it resolves the issue.
  2. Inspect for critters. Check for nests in the furnace blower motor, especially if the RV has been in storage.
  3. Examine wiring. Look for any signs of damaged or chewed wires.
  4. Check furnace fan. Ensure the fan is free of debris and spins without obstruction.
  5. Seek professional help. If the problem persists, especially with wiring, consult a professional electrician for a thorough inspection and repair.

The first thing you can do is switch out the old fuse. There’s a chance that the fuse was old, worn, and met the end of its lifecycle. This is an easy fix that only requires a trip to the store for a new fuse.

However, if you swap the fuse out with a new one and it blows again, you have another problem on your hands. This could be a wiring issue or a seized motor.

Check the furnace your RV has been in storage or if this is the first time firing up your furnace for the year. Sometimes small critters will build a nest in the furnace blower motor, preventing the furnace from working. It’s also worth mentioning that those same critters could chew into wires, so inspecting the wiring is crucial.

If the furnace fan is clear of debris, it spins freely, and the fuse continues to blow. You have a wiring problem. This could be not easy to diagnose and track down. Unless you’re handy with a voltmeter, we recommend bringing your RV in for service.

A professional electrician can troubleshoot and find the root of your wiring problem. They have the knowledge and tools to properly diagnose and fix the problem without damaging your RV or causing an electrical fire.

Staying warm this winter season!

We hope you took away some valuable information from this post. Remember, working with electricity is dangerous as it can shock you or create a fire. Always use proper safety equipment when working around electricity.

Once your furnace is up and running, stock up on propane and hit the road. Camping in the winter is fantastic and beautiful. With a bit of preparation, you can have a great time and make some awesome memories.


Matt Johnson

Senior Content Writer

Matt is an experienced camper and glamping enthusiast with a Master's degree in Wildlife Science from Texas A&M University. Authoring posts for GlamperGear, he shares his wealth of knowledge on picturesque campsites, luxurious accommodations, and the best gear for outdoor adventures. His passion for nature and knack for comfort in the wilderness make him an expert guide for your next camping endeavor.

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