RV Water Heater Blowing Fuses? (Checks + Fixes that Can Help)

You’re in your RV and are looking forward to a hot shown but unfortunately, the heater does not start!

Each time you switch on the propane water heater after replacing the fuse in the fuse panel, the fuse blows immediately.

What causes this? Is this something you may be able to fix and if so where do you even start?

This post explains when your propane RV water heater fuse may keep blowing and what you can do to get the water heater working again consistently.

Note:

  • Always check if the RV water heater is still on warranty or not before attempting to do your own troubleshooting as it can void the warranty
  • The steps provided below are general guidelines – they are only as a general approach to troubleshooting that you can choose to follow. They may not apply to your water heater. Always check the RV water heater manual for troubleshooting tips or consult the water heater supplier for support.

Why the Water heater Fuse Keeps Blowing

If the water heater fuse keeps blowing then there is a short in the wiring leading to the water heater or within the heater circuitry itself.

If you’re up to it and handly, you’ll need to work through the key components of the water heater one at a time systematically eliminating each one until you identify the faulty one.

This will involve disconnecting and isolating each of the listed components at a time, then checking if the replacement fuse (of the same rating – amps as the original) blows or not.

Here is a list of places you can check.

#1. Check for a Short in the Wire Connection from The Fuse Panel to the Water Heater

A short in the wire running from the fuse panel to the heater will cause the fuse to blow. Disconnect the water heater from the wires running from the 12V fuse panel.

Replace the blown fuse with another (water heater disconnected) and check if the fuse blows.

If it stays intact, then there is no short in the wire connection and the fault is further on within the water heater.

If the fuse blows then inspect the connecting wires for any signs of frayed, pinched wire or burn marks and replace them. Check if the fuse still blows after replacing the damaged wires.

#2. A Short in the Solenoid that Controls the Flow of Gas

Disconnect the solenoid that controls the flow of gas from the control board. With the solenoid disconnected, replace the blown fuse and switch on the water, and test if the fuse blows or not.

If it stays intact with the solenoid disconnected then quite likely the fault is with the solenoid switch. You’ll probably need to replace it.

#3. A short in the wire connections to the thermostat

Disconnect the thermostat from the control board. With the thermostat disconnected, check if the fuse blows.

If it remains intact then probably there is a problem with the thermostat or its wire connections.

Check and fix any shorting connections or the thermostat itself and check if this clears the problem.

#4. The Control Board may have an Internal Short

It might be a faulty (shorting) control board. A control board with an internal short will cause the fuse to blow.

Disconnect the control board plug. With the control board connector still unplugged, replace the fuse and switch on the heater.

If the fuse does not blow, then there is probably a short on the control board and it will likely need to be replaced.

Closing Thoughts

If the RV water heater fuses keep blowing, you probably have a short in the wiring leading to the water heater or in the water heater elements.

Start from the outside. Test the 12V wires to the water heater and then proceed to disconnect each of the internal water heater elements namely the solenoid, thermostat, and control board one at a time checking whether the fuse remains intact or not.

Hope this approach helps you find and fix the fault that is causing the RV water heater fuse to keep blowing.

Do not hesitate at any one time to contact a qualified RV technician.

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