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

No hot water in an RV in Sebring is usually a $150 to $450 repair: a burner cleaning, a thermocouple, an igniter, an element, or a valve left in the wrong position. A replacement water heater is $700 to $1,800 installed, and it is what people brace for; it is rarely what they need. Trip fee $75 to $150, diagnosis before any quote.

Check this first (ten minutes)

The bypass valve. Behind the water heater, inside the rig, there is a valve or set of valves that bypasses the tank for winterizing. If it was left in bypass after the tank was drained, you get cold water forever. Set it to normal and try again. This is the answer more often than anyone expects.
Is the tank full? Open the pressure relief valve on the outside of the heater. If air hisses out instead of water, the tank is empty; the element will burn out in seconds without water, and the burner will cycle on the high-limit. Fill it, bleed it, then test.
Which mode fails? Most RV water heaters have gas and electric. Fails on electric only: element or its thermostat. Fails on gas only: burner, igniter, thermocouple or flame sensor, or gas supply. Fails on both: thermostat, high-limit switch, or the control board.
Watch the gas cycle from outside. Open the access door and turn the gas switch on. You should hear a click, see a spark, and get a flame within a few seconds. Click and no flame: no gas or a blocked burner. Flame that lights and dies: thermocouple or flame sensor. No click: board, switch, or the 12V supply.
Look in the burner tube with a flashlight. A mud dauber nest looks like a small mud pot; a spider web looks like nothing until it has blocked the orifice. Both are common after a rig sits through June to September here.
Press the reset button. The high-limit reset is behind the access door on most units. It trips when the tank runs dry or overheats.

What is usually wrong

What you observe	Likely cause	Fix and cost
Cold water on both modes, tank checks full	Bypass valve in bypass	Reset the valve; trip fee only
Sparks, no flame	Burner tube blocked, or gas supply	Burner clean $150 to $250
Lights, then goes out	Thermocouple or flame sensor	$150 to $300
No spark, no click	Control board, switch, or 12V supply	Board $250 to $450
Electric mode dead, gas works	Heating element or thermostat	$150 to $350
Hot water runs out fast	Bypass partly open, check valve, or scale	$150 to $350
Rusty water, dripping tank seam	Anode gone, tank corroded	Anode $100 to $150; tank replacement $700 to $1,800
Board dead the day after a storm	Surge through the 12V system	Board, and we test the converter too

These match the pricing page on top of the trip fee and $125 to $190 hourly labor.

Why water heaters fail here

The burner assembly on an RV water heater is a small, sheltered, warm cavity that opens to the outside through the access door. From late April to mid-November in Highlands County it is also damp. Mud daubers build in it. Spiders web the orifice. Rust flakes off the burner tube in the humidity and falls into the orifice. A rig that sat in a storage lot or on a resort site from April to November comes out with a burner that cannot light, and the owner’s first thought is a new water heater. It is a cleaning.

The tank side has its own Florida problem. The water at the fish camps on Lake Istokpoga and in the older parks is often hard well water, and a tank that sits full through a hot, humid summer with nobody drawing from it corrodes from the inside. On Suburban tanks the sacrificial anode rod is what takes that corrosion instead of the steel; it lasts a year or two here and then the tank starts. Atwood tanks are aluminum and do not use an anode, but they do scale. Draining and flushing the tank before you leave for the summer, and pulling the anode to look at it, is ten minutes that saves a tank.

And lightning. Florida records more lightning per square mile than any other state, and the control board on a modern water heater is on the 12V system, downstream of the converter. A strike near a park’s electrical service that kills the converter often takes the water heater board with it. If nothing on the heater responds the day after a storm, that is what happened.

Repair or replace

Repair when it is the burner, a thermocouple, an igniter, an element, a thermostat, a board, or an anode, which is most calls. Replace when the tank itself is leaking at a seam, or when a unit over about fifteen years old needs a board and an element and has a tired tank. Tank replacement is $700 to $1,200; going tankless is $1,200 to $1,800 and it is worth a conversation if you live in the rig and run out of hot water. We give you both numbers.

When to call

Now if there is no hot water and you are living in the rig. In November, on arrival, if the rig sat through the summer, because the burner check takes a minute and it is on the arrival checklist for a reason. We do these on site across Sebring, Avon Park, Lake Placid, and Lorida, and the plumbing and water heater page covers the rest of the water system.

Frequently Asked Questions

How much does RV water heater repair cost in Sebring?

$150 to $450 for the common repairs: burner cleaning, thermocouple or flame sensor, igniter, heating element, thermostat, or anode rod. A replacement water heater is $700 to $1,800 installed depending on tank or tankless. Most won't-light calls after a summer in storage end in the first range.

The water heater clicks but never lights. Is it the gas valve?

Usually not. Clicking means the igniter is sparking. No flame means no gas reaching the burner or no flame being sensed. After a wet Florida summer the usual find is a mud dauber nest or rust in the burner tube; after that it is the thermocouple or flame sensor. The gas valve is last on the list.

Hot water only lasts two minutes. Is the heater too small?

Check the bypass valve first. If the rig was winterized or the tank was drained and the bypass was left in the bypass position, cold water is going straight to the taps and the tank is not in the loop. If the bypass is right, a failed check valve or a heavily scaled tank is next.

Do I need a new anode rod?

On a Suburban tank, yes, every year or two here. Hard well water at the fish camps and a tank that sits full through a humid summer eat anodes fast. A rod that is down to the wire means the tank is next. It is a $30 part and a fifteen-minute job while we are already there.