Guides › RV Water Heater Not Lighting (Propane)
RV Water Heater Not Lighting (Propane)
⚠️ Educational only — follow your service manual, use rated jack stands, and read our safety rules before you start.
Safe, owner-level checks for a propane RV water heater that won't fire — and where DIY should stop.
⚠️ Safety first
- If you smell propane (LP), shut off the tank valve, extinguish flames, open doors, leave the RV and don't operate switches. Call for service.
- Never use an open flame to search for leaks — use soapy water.
- Make sure LP and CO detectors in the RV work and are in date.
- Turn the heater off and let the burner cool before reaching into the compartment.
Tools & supplies
- Flashlight
- Soft brush / compressed air
- Soapy water spray bottle
- Multimeter (12 V checks)
🧰 Tools & parts needed / Recommended gear
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- Digital multimeter — Checks 12 V supply, fuses and thermostat circuits. view options (paid link)
- Combination LP/CO detector — Early warning for propane leaks and CO. ⚠️ If you smell propane: shut off, ventilate, leave, call a pro. view options (paid link)
- Water heater flush wand — Clears sediment that causes poor performance. view options (paid link)
- Leak detection solution — Bubble-tests LP fittings safely (never use a flame). view options (paid link)
- Compressed air duster — Clears spider webs and debris from burner tubes. view options (paid link)
Steps
- Confirm the tank valve is open and other LP appliances (stove) work. If the stove won't light either, the issue is supply, not the heater. A newly opened tank may need the regulator reset — close appliances, open the valve slowly.
- Check the water heater is full of water (open a hot tap until steady flow) and the bypass valve is not left in winterize mode.
- Verify 12 V power: the switch indicator, fuse, and battery voltage (low voltage often causes ignition lockout).
- Reset the lockout by turning the switch off for 30 seconds and back on. Listen outside for the clicking igniter.
- Inspect the burner tube and outside vent for spider webs, nests, or debris (mud daubers love these); clean gently.
- Look at the igniter/flame sensor electrode for carbon and correct gap per the manual.
🛑 When to call a pro
- Any gas valve, regulator, or control board replacement.
- You smell gas or soapy-water test bubbles.
- The flame is yellow, sooty, or lifts off the burner.
Printable checklist
WrenchReady — RV Water Heater Not Lighting (Propane) · Date: ________ Vehicle: ________________
Video walkthroughs
Third-party videos embedded from YouTube; not produced or endorsed by us. Always follow your service manual.
FAQ
What should I do if I smell propane in my RV?
Shut off the tank valve, extinguish any flames, open doors, leave the RV and don't operate switches. Call for service.
Why won't my RV water heater light?
Common owner-level causes include a closed or empty LP supply, a tank that isn't full of water or a bypass valve left in winterize mode, low 12 V battery voltage, an ignition lockout, or spider webs and debris in the burner tube.
Can I repair the gas valve or control board myself?
No. Gas valve, regulator and control board replacement should be done by a qualified technician.
Related guides
References
Written by the WrenchReady team from general public knowledge. Specifications vary — your owner's/service manual is the authority.