The bypass valve: check it first, always
When a rig is winterized, valves behind the water heater are turned so antifreeze routes around the tank. If they're never turned back, cold water keeps bypassing the tank forever — the heater can be working perfectly, heating six gallons that nothing ever flows through, while your shower runs cold.
Find the valves behind the heater's interior access panel and confirm the bypass is open to the tank (typically: valves on the in/out lines open, the bypass line between them closed). Lukewarm-then-cold water can also be a partially-turned valve mixing cold straight into the hot line.
Electric side: the element and the hidden reset button
No hot water on electric mode usually means the heating element or the ECO (emergency cut-off) has tripped. Behind the outside access panel, under a small rubber cap or insulation, live one or two red reset buttons — press firmly; a click means it had tripped, and that's often the whole fix.
If it trips again or never heats, test the element: power off, pull the leads, and meter resistance — roughly 10–16 ohms is healthy; an open circuit means it's burned out. Elements die instantly if run without water in the tank (that bypass valve again — an empty tank plus the switch flipped on kills an element in seconds). Replacements are cheap; drain the tank and use an element wrench.
Gas side: spark, flame, and the dirty burner
On gas mode you should hear the igniter tick and the burner light with a steady blue roar within a few seconds. Clicking with no flame means gas isn't arriving (tank valve, excess-flow lockout from opening the tank too fast, air in the line after a fill — cycle it a few times) or the burner orifice is blocked. Spiders love propane odorant; their webs in the burner tube are a legendary cause of weak yellow flames and soot.
Flame that lights then drops out points at the flame sensor or thermocouple not proving the flame — clean the sensor tip gently and make sure it sits in the flame path. Repeated lockouts after those checks are control-board territory.
Runs out too fast? That's a different problem
Six gallons of properly hot water makes a longer shower than people expect — if yours runs cold in two minutes, suspect the check valve/dip tube arrangement mixing cold into the hot outlet, a tank half-full of scale (flush it — see our anode rod guide), or on electric mode alone, simply the slower recovery rate. Gas reheats roughly twice as fast as electric; running both together is fastest.
And if the relief valve drips while heating: that's often normal thermal expansion, not a failure. Air-charge the tank (water off, relief valve open, let the tank burp) before replacing anything.
Stuck on this one? Put Major in your pocket.
Tell RV Journey Genie your make, model, and symptom and get a step-by-step fix — by text, voice, or photo — before you ever call the shop.
Frequently asked questions
Why do I have no hot water in my RV after winterizing?
The water heater bypass valve is almost certainly still in its winterize position, routing cold water around the tank. Open the interior access to the heater lines and return the valves to normal flow. It's the single most common cause of springtime "broken" water heaters — and the heater is usually fine.
Where is the reset button on an RV water heater?
Behind the outside access panel: look for one or two small red buttons (the ECO/thermal cutoffs) under a rubber cap or insulation near the thermostat, and press firmly until they click. A tripped ECO kills the electric element, and on many models the gas side too. If it trips repeatedly, test the element and thermostat.
Why did my RV water heater element burn out?
Electric elements must be submerged — flipping the electric switch on with an empty or bypassed tank burns the element out in seconds. Always confirm the tank is full (run the hot tap until water flows steadily) before enabling electric mode, especially after winterizing or tank maintenance.