If your RV water heater is not working on propane but works on electric, the issue is usually isolated to the propane ignition system, gas supply, or safety controls. Propane mode relies on several components working together, and a failure anywhere in that chain will prevent the burner from lighting.

This guide explains the most common reasons an RV water heater won’t run on propane, what symptoms to look for, and what you can safely check before calling a professional.

Safety Notice: This article is provided for informational purposes only. RV systems may include electrical, propane, plumbing, and mechanical components that can pose serious safety risks. Always follow manufacturer guidelines and proper safety procedures. When in doubt, seek assistance from a qualified RV technician.

Common Symptoms of This Problem
You may be dealing with this issue if:

• Hot water works on electric but not propane
• You hear clicking but the burner never lights
• The water heater tries to ignite, then shuts down
• The propane tank is full but there’s no hot water
• No error codes are displayed

These symptoms usually point to ignition, gas flow, or flame-sensing problems.

How RV Water Heaters Work on Propane
On propane mode, the water heater uses a control board to ignite gas at the burner and verify a flame.
The basic flow is:
Propane tank → regulator → gas valve → burner → ignition electrode → flame sensor → hot water
If any step fails, the system will shut down for safety.

1. Propane Is Turned Off or Air Is in the Lines (Very Common)
After changing propane tanks or coming out of storage, air trapped in the lines can prevent ignition.
Check:

• Propane tank valve is fully open
• Other propane appliances (stove, furnace) work
• Stove burners light smoothly

If the stove sputters before lighting, air may still be in the lines. Let it burn for a minute, then retry the water heater.

2. Water Heater Propane Switch Is Turned Off
Most RVs have a separate switch for propane mode.
Check:

• Inside RV control panel
• Any labeled switch for “LP” or “Gas”

If propane mode is off, the heater will not attempt ignition.

3. Faulty or Dirty Ignition Electrode
The ignition electrode creates the spark that lights the propane.
Common issues include:

• Carbon buildup
• Bent or cracked electrode
• Improper gap

Symptoms often include repeated clicking with no ignition.

4. Burner Tube Is Dirty or Obstructed
Dirt, rust flakes, spider webs, and insects commonly block burner tubes.
This can cause:

• Weak flame
• No ignition
• Burner lighting briefly then shutting off

Carefully inspecting and cleaning the burner area often restores operation.

5. Failed or Dirty Flame Sensor
Once the burner lights, the system must confirm a flame. If it doesn’t, the gas shuts off.
Signs of flame-sensing problems:

• Burner lights briefly, then shuts down
• Repeated ignition attempts
• No sustained flame

A dirty or failing sensor is a common cause.

6. Bad Control Board
The control board manages ignition timing, gas flow, and safety shutdowns.
Possible signs of a bad board:

• No spark at all
• Random shutdowns
• Works intermittently
• No error codes despite failure

Control boards are not repairable and usually require replacement.

7. Propane Regulator or Gas Pressure Issue
Low gas pressure can prevent proper ignition.
Possible causes:

• Failing propane regulator
• Ice buildup in cold weather
• Multiple appliances running at once

If other propane appliances struggle or go out, pressure issues may be the cause.

8. Safety Switch or Thermostat Problem
RV water heaters include safety switches that shut down propane if overheating or unsafe conditions are detected.
Symptoms may include:

• No ignition attempts
• Heater locks out until reset
• Normal electric operation

Some resets are manual and located behind the exterior access panel.
When to Stop Troubleshooting and Call a Professional

Contact an RV technician if:

• You smell propane
• The burner area shows soot or scorching
• Ignition continues to fail after basic checks
• You’re unsure how to access components safely

Propane systems should always be treated with caution.

How to Prevent Propane Water Heater Problems

• Keep burner area clean and covered during storage
• Use propane regularly to prevent buildup
• Inspect burner and electrode annually
• Ensure tank valves are opened slowly

If your RV water heater is not working on propane, the most common causes are air in the gas lines, dirty burner components, ignition electrode problems, or a failing control board. By checking propane supply, ignition behavior, and burner condition, you can often identify the issue quickly and restore hot water.

Related articles you may find helpful:
RV Water Heater Not Working on Electric

Written by Dan Harvickson, RV troubleshooting specialist