RV water heater not working: what to check and what the repair costs

No hot water is one of the few RV problems where the odds strongly favor a cheap answer. The great majority of these calls across Zephyrhills and east Pasco County end at a $150 to $450 repair, and a fair number end at a part costing less than a tank of fuel. Replacement at $700 to $1,800 is the exception, not the rule.

Check this first (fifteen minutes)

If it runs on gas:

Confirm you have propane and that other gas appliances light. Obvious, and it is the answer more often than anyone admits.
Listen at the outside access panel. You should hear the gas valve click, then a series of sparks, then a whoosh. Sparks with no whoosh means gas is not arriving or the burner is blocked. No sparks at all means the board or the electrode.
Look into the burner tube with a flashlight. In Florida, mud daubers and paper wasps build in that tube during the months the rig sits, and a blocked tube means the flame cannot establish. This is one of the most common causes we find in November, and it is a cleaning rather than a part. Rust scale that has flaked off the flue in the humidity does the same thing.
Find the ECO / high-limit reset. Usually a small button behind the outside panel. A tripped high limit locks the unit out, and it is often what people mean when they say the heater “just stopped”.

If it runs on electric:

Check the switch inside, the breaker, and the pedestal. Many rigs have an interior switch for the electric element that is easy to leave off. After a storm, check for a tripped GFCI too.
Make sure the tank is full of water. Running an electric element in an empty tank burns it out within minutes, and that is the single most common way people destroy an element after a rig has sat drained.

What is usually wrong

What you observe	Likely cause	Fix and cost
Sparks, no flame	Blocked burner tube, often a wasp nest or rust scale	Clean and service, $150 to $300
No spark at all	Electrode, control board, or a corroded ground	$200 to $450
Lights, then goes out in seconds	Thermocouple or flame-sense circuit	$150 to $350
Works on gas, not on electric	Failed heating element or its thermostat	$200 to $450
Works on electric, not on gas	Gas valve, regulator pressure, or burner	$200 to $500
Water lukewarm on both	Thermostat, or a tank half full of sediment	$150 to $450
Rusty water, weeping tank	Tank corrosion, often a neglected anode	Replacement $700 to $1,800
Steady stream from the relief valve	Lost air gap or a failed valve	Often under $200
Board dead after a thunderstorm	Surge through the pedestal	$250 to $450

These come from the pricing page and sit on top of the $75 to $150 trip fee and $125 to $190 hourly labor.

The Florida specifics

Wasps. Mud daubers and paper wasps are relentless here and they love the burner tube of a water heater and the furnace intake. The winter season runs November through April, and a rig that sat on its space or in a storage lot from May to October comes back with nests in both. Screens over those openings cost a few dollars and prevent an annoying share of our no-heat calls.

Corrosion. Summer dew points sit in the high 60s and low 70s for months, and relative humidity climbs past 90 percent every night. The outside access compartment of a water heater is not sealed against that. Electrodes, the ground connection for the board, the burner assembly, and the flue all corrode faster here than in a dry climate, and a fair number of “no spark” calls are a green ground screw rather than a dead board. Steel tanks depend on their anode rod more here, not less; check it every season.

Sitting drained. Many owners drain the water heater before going north, which is right. The mistake is switching the electric element on in November before the tank is full again. That one habit accounts for a meaningful number of dead elements every arrival season.

Park water. Sediment collects in a tank that has never been flushed and insulates the bottom of the tank from the burner. The symptom is lukewarm water and a heater that runs constantly. Flushing a tank takes twenty minutes and is worth doing every season.

Tank or tankless, if it comes to replacement

If the tank is perforated, the decision is which way to replace it. Tank units are cheaper, simpler, and take a known footprint. Tankless units give endless hot water and take a bigger gas and electrical demand, and they are less forgiving of low water pressure. In a rig that mostly sits at a park with full hookups, a tankless is a genuine comfort upgrade. In a rig that dry camps, it often is not. We will tell you which one fits the way you actually use the rig rather than defaulting to the bigger invoice.

What to expect on the call

Tell us the brand off the outside panel, whether it fails on gas, electric, or both, and what you hear when it tries to light. That conversation often ends with a part and an appointment rather than a diagnosis visit. We work on site at your park space, storage lot, or driveway across Zephyrhills, Dade City, Wesley Chapel, Lutz, and Plant City, and the repair cost calculator gives you a range before you call.

Frequently Asked Questions

My RV water heater will not light. What is the usual cause?

On a gas water heater, the top three are a wasp-blocked or rusty burner tube, a failed thermocouple or electrode, and a tripped high-limit (ECO) switch. All three are inexpensive. Mud daubers and other wasps building in the burner tube over a Florida summer is genuinely one of the most common causes we find on rigs whose owners have just come back.

How much does RV water heater repair cost?

$150 to $450 for the common repairs: thermocouple, element, anode rod, thermostat, or a burner cleaning. A full replacement runs $700 to $1,800 installed depending on whether it is a tank or tankless unit. The diagnosis comes first, because most no-hot-water calls end in the cheaper column.

Water is dripping from a valve on the outside of the water heater. Is it broken?

Probably not. That is the pressure and temperature relief valve, and a small weep after the water heats is normal as the tank pressurizes. A steady stream is not, and usually means the air gap at the top of the tank has been lost, which is a five-minute fix, or the valve itself has failed.

Do I need to replace the anode rod?

If you have a Suburban with a steel tank, yes, roughly annually, and in this humidity and on park water it does not last longer. That rod exists to corrode instead of your tank. Atwood and some newer tanks are aluminum-clad and do not use one. Getting this wrong is how a perfectly good water heater tank ends up perforated.