RV Water Heater FAQs

RV Water Heater FAQs

RV Water Heater Parts and RV Water Heater Questions Answered by RVWaterHeaterGuys.com

RV water heaters come in several different sizes, fuel types and configurations. Whether you are repairing a Suburban, Dometic or Girard water heater, identifying the correct model and understanding how the system operates are the first steps toward finding the right replacement part.

Below are answers to the most common questions RV owners ask about RV water heaters, replacement parts, maintenance and complete replacement units.

What are the most common RV water heater brands?

The most common RV water heater brands are Suburban, Dometic and Girard. Dometic also manufactures replacement water heaters and parts for many older Atwood water heater models.

RVWaterHeaterGuys.com specializes in complete water heaters and replacement parts for:

  • Suburban RV water heaters

  • Dometic and Atwood RV water heaters

  • Girard tankless RV water heaters

Where can I buy RV water heater parts online?

RV water heater replacement parts can be purchased online from RVWaterHeaterGuys.com. We carry parts for Suburban, Dometic, Atwood and Girard water heaters, including control boards, thermostats, heating elements, burners, igniters, gas valves, switches, tanks, heat exchangers, sensors and pressure relief valves.

How do I find the correct part for my RV water heater?

Start by locating the manufacturer, model number and serial number on the water heater identification label. The label is commonly found behind the exterior access door or on the side of the water heater.

Once you have the model number, search for parts by:

  • Water heater manufacturer

  • Water heater model

  • Part number

  • Replacement part category

Do not identify a water heater only by its gallon capacity or exterior door size. Several models may look nearly identical while using different internal parts.

Where is the model number on an RV water heater?

The model and serial number are normally printed on a label located behind the exterior water heater access door. On some installations, the label may be placed on the side of the water heater and may be difficult to see without partially removing the unit.

The model number should be confirmed before ordering replacement parts or a complete water heater.

What are the most common RV water heater parts that fail?

Commonly replaced RV water heater parts include:

  • Control boards

  • Thermostats and ECO switches

  • Electric heating elements

  • Burner assemblies

  • Igniters and electrodes

  • Gas valves

  • Thermal cutoff switches

  • Pressure relief valves

  • Water flow sensors

  • Temperature sensors

  • Mixing valves

  • Check valves

  • Tankless heat exchangers

  • Anode rods

  • Drain plugs

  • Exterior switches

Many water heater problems can be repaired by replacing an individual component rather than replacing the complete appliance.

Do RV water heaters run on propane or electricity?

RV water heaters may operate on propane, 120-volt AC electricity or a combination of both.

Common configurations include:

  • Propane-only tank water heaters

  • Gas and electric combination water heaters

  • Propane-fired tankless water heaters

  • Water heaters with engine-assisted heating systems

Even propane water heaters commonly require 12-volt DC power to operate the control board, gas valve and ignition system.

Can an RV water heater run on propane and electricity at the same time?

Many gas-and-electric tank water heaters can operate on propane and 120-volt electricity at the same time. Using both heat sources can reduce recovery time and provide hot water more quickly.

This does not apply to every model. Tankless RV water heaters typically use propane to heat the water and 12-volt DC electricity to operate their controls.

What is the difference between a tank and tankless RV water heater?

A traditional RV water heater stores and heats a fixed amount of water, commonly six or ten gallons. Once that hot water is used, the heater needs time to recover.

A tankless RV water heater heats water as it flows through the unit. It can provide a continuous supply of hot water as long as the required propane, electrical power and water flow remain available.

Tank water heaters are generally less sensitive to changes in water flow. Tankless models offer longer showers but rely more heavily on consistent water pressure and flow.

Can I replace a tank-style RV water heater with a tankless model?

Yes, many tank-style RV water heaters can be replaced with a tankless unit. However, the replacement must be selected according to the existing opening, plumbing arrangement, propane supply, electrical requirements and exterior door dimensions.

A conversion may also require:

  • A replacement exterior door

  • An adapter panel

  • Plumbing modifications

  • Wiring changes

  • A wall-mounted temperature controller

Always compare the dimensions and installation requirements of the existing and replacement water heaters.

What size RV water heater do I need?

Traditional RV water heaters are commonly available in six-gallon and ten-gallon sizes, although other capacities are available. The correct size depends on the existing cutout, available installation depth, plumbing layout and hot-water demand.

Replacing an existing unit with the same size and mounting configuration is usually the simplest option. A larger water heater may require additional space behind the exterior wall.

What is an XT RV water heater?

An XT water heater uses a mixing system to blend very hot water from the tank with cold water as it leaves the appliance. This allows a smaller tank to provide more usable hot water than its physical capacity would normally suggest.

For example, a six-gallon XT water heater can deliver a greater effective volume of hot water through temperature mixing.

Do all RV water heaters use an anode rod?

No. Suburban tank-style water heaters commonly use a replaceable anode rod to protect the steel tank from corrosion.

Dometic and Atwood water heaters generally use an aluminum tank and do not require an anode rod. These models normally use a nylon drain plug instead.

Tankless RV water heaters do not use a traditional storage tank and generally do not have an anode rod.

How often should a Suburban RV water heater anode rod be replaced?

The anode rod should be inspected regularly and replaced when most of its material has deteriorated. Inspection every six to twelve months is a reasonable maintenance schedule, although hard water and frequent use can cause faster deterioration.

The rod should be replaced when approximately 75 percent of its material has been consumed.

Do Dometic or Atwood RV water heaters need an anode rod?

No. Dometic and Atwood aluminum-tank water heaters are designed to use a nylon drain plug rather than an anode rod.

Installing an aftermarket anode rod in a Dometic or Atwood water heater is not recommended and may damage the tank threads or contribute to corrosion.

How long does an RV water heater last?

The lifespan of an RV water heater depends on water quality, maintenance, winterization and frequency of use. A properly maintained tank-style water heater can often remain in service for ten years or longer.

Tank corrosion, freeze damage, repeated leaks or the increasing unavailability of model-specific parts may make complete replacement more practical.

Do you sell complete RV water heaters?

Yes. RVWaterHeaterGuys.com sells complete RV water heaters and replacement parts for Suburban, Dometic and Girard models.

Available options include:

  • Propane RV water heaters

  • Gas and electric RV water heaters

  • Six-gallon water heaters

  • Ten-gallon water heaters

  • XT water heaters

  • Tankless RV water heaters

Do you sell OEM RV water heater parts?

RVWaterHeaterGuys.com carries genuine OEM parts and compatible replacement parts for Suburban, Dometic, Atwood and Girard RV water heaters.

Every product listing identifies the compatible models and available manufacturer part numbers whenever that information is available.

RV Water Heater Troubleshooting Guide

Suburban, Dometic, Atwood and Girard RV Water Heater Help

RV water heater problems can be caused by the water supply, propane system, 12-volt electrical system, 120-volt electrical system or the appliance itself. The symptoms below can help narrow down which component or system should be inspected first.

1. Why is my RV water heater not heating?

An RV water heater may stop heating because of:

  • No propane supply

  • No 12-volt DC power

  • No 120-volt AC power

  • A tripped circuit breaker

  • A blown fuse

  • A failed thermostat

  • A tripped or failed ECO switch

  • A damaged control board

  • A failed heating element

  • A dirty burner

  • A damaged igniter

  • A closed bypass valve

  • Insufficient water flow through a tankless unit

Begin by determining whether the problem occurs on propane, electricity or both. This helps separate a fuel-specific problem from a component shared by both operating modes.

2. Why does my RV water heater work on propane but not electricity?

When an RV water heater works on propane but not on electricity, the problem is usually within the 120-volt AC heating circuit.

Common causes include:

  • A tripped circuit breaker

  • A failed electric heating element

  • A damaged electric thermostat

  • A faulty relay

  • A disconnected wire

  • A failed interior or exterior electric switch

  • No 120-volt power reaching the water heater

The propane system heating normally usually indicates that the tank and much of the basic control system are still functioning.

3. Why does my RV water heater work on electricity but not propane?

When the electric heating element works but the propane burner does not, inspect the propane and ignition systems.

Possible causes include:

  • An empty propane cylinder

  • A closed propane valve

  • Air in the propane line

  • Low propane pressure

  • A dirty burner or burner tube

  • A clogged gas orifice

  • A damaged igniter

  • A faulty gas valve

  • A failed control board

  • A defective flame-sensing electrode

Because the water heats electrically, the tank and plumbing are probably not the source of the problem.

4. Why does my RV water heater click but not ignite?

Clicking usually indicates that the control board is attempting to create a spark. Failure to ignite may be caused by:

  • No propane reaching the burner

  • Air in the propane line

  • A dirty burner

  • A blocked gas orifice

  • Incorrect igniter positioning

  • A cracked ignition electrode

  • Low propane pressure

  • A faulty gas valve

  • A weak or missing spark

Confirm that another propane appliance operates correctly before assuming that the water heater itself has failed.

5. Why does my RV water heater ignite and then shut off?

A burner that ignites and shuts down shortly afterward may not be proving the flame correctly.

Common causes include:

  • A dirty flame-sensing electrode

  • Improper electrode positioning

  • A weak ground connection

  • Low propane pressure

  • A restricted burner

  • A damaged igniter wire

  • A failing gas valve

  • A control board problem

  • Insufficient airflow

The same electrode may create the ignition spark and confirm that a flame is present.

6. Why is my RV water heater not getting hot enough?

Lukewarm water may be caused by:

  • A bypass valve left partially open

  • An exterior shower mixing hot and cold water

  • A failed check valve

  • A faulty mixing valve

  • A weak electric heating element

  • Burner or propane-pressure problems

  • Mineral buildup inside the tank

  • Excessive water flow through a tankless heater

  • A faulty temperature sensor

  • A thermostat problem

Check the water heater bypass system and exterior shower controls before replacing parts. An open hot-and-cold shower valve can mix cold water into the RV’s hot-water plumbing even when the shower head is turned off.

7. Why do I have hot water at the water heater but not at the faucets?

When the water heater tank is hot but the faucets receive cold or lukewarm water, the problem is usually in the plumbing rather than the heating system.

Check for:

  • Incorrect bypass-valve positions

  • A stuck outlet check valve

  • A failed mixing valve

  • Hot and cold water mixing at an exterior shower

  • A plumbing restriction

  • A reversed plumbing connection

This commonly occurs after an RV has been winterized or de-winterized.

8. Why is no water coming from my RV’s hot-water faucets?

No flow from the hot-water side may be caused by:

  • A closed water-heater inlet valve

  • An incorrect bypass-valve position

  • A stuck outlet check valve

  • A clogged mixing valve

  • Sediment or mineral buildup

  • A frozen water line

  • A plumbing obstruction

If cold water flows normally but no hot-side water is available, inspect the valves and fittings surrounding the water heater.

9. Why does my tankless RV water heater turn hot and cold?

Temperature fluctuations in a tankless RV water heater are commonly caused by changing water flow.

Possible causes include:

  • Low campground water pressure

  • A clogged inlet screen

  • A restricted shower head

  • A water-saving fixture that reduces flow too far

  • Hot and cold water being mixed at the faucet

  • A faulty flow sensor

  • A damaged temperature sensor

  • Mineral buildup in the heat exchanger

  • An inconsistent propane supply

Tankless water heaters generally operate best when the desired temperature is selected at the controller and the hot faucet is opened without adding large amounts of cold water.

10. Why does my tankless RV water heater shut off during a shower?

A tankless heater may shut off when water flow drops below the minimum rate required to keep the burner operating.

This can happen because of:

  • Low water pressure

  • A restrictive shower head

  • A clogged water inlet filter

  • A partially closed faucet

  • A failing water flow sensor

  • An inconsistent RV water pump

  • Excessive mixing with cold water

  • A temperature or ignition fault

Opening the hot-water faucet farther may temporarily restore operation, but recurring shutdowns should be diagnosed.

11. Why does my RV tankless water heater only work with the faucet fully open?

This usually means the water heater is not detecting enough flow at lower faucet settings.

Possible causes include:

  • Low incoming water pressure

  • A clogged inlet filter

  • A restricted faucet aerator

  • A restrictive shower head

  • A failing flow sensor

  • Mineral buildup inside the water heater

  • Restrictions in the RV plumbing

Tankless units depend on a minimum water-flow rate to activate the ignition sequence.

12. Why is my RV water heater leaking?

The source of an RV water heater leak may be:

  • A loose plumbing fitting

  • A damaged drain plug

  • A deteriorated anode rod connection

  • A leaking pressure relief valve

  • A failed check valve

  • A cracked tank

  • A freeze-damaged valve

  • A split tankless heat exchanger

  • A damaged gasket or O-ring

Determine the exact source of the water before ordering parts. A leaking fitting or valve can often be replaced, while a cracked storage tank may require a complete water heater.

13. Why is water dripping from the pressure relief valve?

Occasional dripping from the pressure and temperature relief valve can occur as water heats and expands inside the tank.

Persistent leaking may be caused by:

  • Excessive water-system pressure

  • A lost air pocket inside the tank

  • Debris inside the valve

  • A worn valve seat

  • A damaged pressure relief valve

  • A failed check valve

  • Excessive water temperature

The valve should not be plugged or capped.

14. How do I restore the air pocket in an RV water heater?

The air pocket at the top of a tank-style RV water heater allows heated water to expand. The pocket may gradually disappear during normal use, causing the pressure relief valve to drip.

A commonly used procedure is:

  1. Turn off the water heater.

  2. Turn off the water supply or water pump.

  3. Open a hot-water faucet.

  4. Open the pressure relief valve until water stops flowing.

  5. Allow the relief valve to close.

  6. Close the faucet.

  7. Restore the water supply.

The tank should refill while leaving an air pocket at the top.

15. Why does my RV water heater make popping or rumbling noises?

Popping, crackling or rumbling noises are often caused by sediment and mineral deposits inside the tank. Water trapped beneath the deposits can produce noise as it heats.

Flushing the water heater may remove loose sediment. Heavy scale can reduce heating efficiency and shorten the life of the tank or electric heating element.

16. Why does my RV hot water smell like rotten eggs?

A rotten-egg or sulfur smell is usually caused by a reaction involving water chemistry, bacteria and the anode rod in a tank-style water heater.

Flushing and sanitizing the water system may resolve the odor. In Suburban water heaters, the type and condition of the anode rod can also affect the smell.

The odor does not necessarily mean that the water heater tank has failed.

17. Why is there soot around my RV water heater?

Soot around the exterior vent indicates incomplete combustion.

Possible causes include:

  • A dirty burner

  • A blocked burner tube

  • Insect nests or debris

  • A misaligned burner

  • An incorrect air-to-fuel mixture

  • Improper propane pressure

  • A damaged gas orifice

  • Restricted exhaust airflow

A properly operating propane burner should normally produce a strong blue flame with little or no soot.

18. Why is my RV water heater flame yellow?

A yellow or unstable burner flame can indicate incomplete combustion.

Common causes include:

  • Restricted airflow

  • Dirt or rust inside the burner tube

  • Spider webs or insect nests

  • An incorrect burner adjustment

  • A damaged gas orifice

  • Improper propane pressure

The burner assembly and combustion area should be inspected and cleaned before replacing unrelated electrical components.

19. Why does my RV water heater have no power?

Even propane-fired RV water heaters commonly require 12-volt DC power.

Check:

  • The RV battery voltage

  • The 12-volt fuse

  • The water heater switch

  • Wiring connections

  • Ground connections

  • Thermal cutoff

  • Thermostat and ECO circuit

  • Control board

  • 120-volt circuit breaker when testing electric mode

Low voltage can cause intermittent operation, failed ignition or repeated fault codes.

20. How do I reset an RV water heater?

Some RV water heater problems can be cleared by turning the appliance off and disconnecting its power briefly before restarting it.

Depending on the model, this may involve:

  • Turning off the interior water heater switch

  • Disconnecting 12-volt power

  • Turning off the 120-volt circuit breaker

  • Allowing the control board to power down

  • Restoring power and attempting another heating cycle

A reset may clear a temporary fault, but recurring shutdowns usually indicate an unresolved problem.

21. Where is the RV water heater reset button?

Some tank-style RV water heaters have resettable thermostat or ECO switches located behind the exterior access door. They may be covered by a rubber panel or located near the thermostat assembly.

Not every RV water heater has a manual reset button. Tankless models often display a fault code or reset through the control panel instead.

22. Why does my RV water heater keep tripping the reset button?

Repeatedly tripping a thermostat or ECO reset may indicate:

  • An overheating condition

  • A faulty thermostat

  • Loose wiring

  • A failing heating element

  • A damaged control board

  • Poor contact between the thermostat and tank

  • A restricted mixing valve

  • An incorrect replacement component

A reset that trips repeatedly should not be treated as a permanent repair.

23. Why does my RV water heater keep blowing a fuse?

A repeatedly blown 12-volt fuse can be caused by:

  • Damaged wiring

  • A shorted gas valve

  • A failed control board

  • A damaged igniter wire

  • A pinched wire

  • Moisture or corrosion in an electrical connection

  • An incorrect fuse size

Do not install a higher-amperage fuse to stop it from blowing. The electrical fault should be located first.

24. How can I tell whether my RV water heater element is bad?

A failed electric heating element commonly causes the water heater to stop heating on 120-volt electricity while continuing to operate on propane.

Other signs include:

  • The circuit breaker trips

  • The element has continuity to ground

  • The element receives voltage but does not heat

  • The element was energized while the tank was empty

  • Visible damage is present after removal

An electric element can burn out quickly when operated without water covering it.

25. What happens if I turn on an RV water heater without water in it?

Running the electric heating element in an empty tank can destroy the element very quickly.

Operating the propane burner with an empty tank can overheat the appliance and damage internal components. Tank-style water heaters should be completely filled before either heat source is turned on.

Tankless models operate differently because they heat water only while flow is detected.

26. How long does an RV water heater take to heat up?

Heating time varies by tank size, incoming water temperature and heat source.

A six-gallon tank-style RV water heater commonly requires approximately 20 to 40 minutes to reach operating temperature. Using propane and electricity together on a combination model can reduce recovery time.

Tankless units begin producing hot water shortly after adequate flow is detected, although hot water must still travel through the plumbing before reaching the faucet.

27. How long will a six-gallon RV water heater provide hot water?

The amount of usable hot water depends on:

  • The tank temperature

  • Incoming cold-water temperature

  • Shower flow rate

  • Whether cold water is mixed at the faucet

  • Whether the heater continues operating during use

  • Whether the unit has an XT mixing system

A standard six-gallon tank does not necessarily limit the user to exactly six gallons of shower water because the heated water is mixed with cold water at the fixture.

28. Can I leave my RV water heater on all the time?

Many RV water heaters are designed to cycle automatically and maintain water temperature while the RV is occupied.

However, the heater should be turned off when:

  • The water system is drained

  • The RV is being winterized

  • The water heater is leaking

  • Propane service is being performed

  • The RV is stored without water in the tank

  • The appliance is malfunctioning

Never operate a tank-style water heater unless the tank is full.

29. Can I run my RV water heater while driving?

Whether a propane appliance should be operated while traveling depends on the RV, water-heater design, local restrictions and owner’s manual instructions.

Propane appliances must be turned off before entering fuel stations and other areas where open flames or ignition sources are prohibited.

30. How do I know whether my RV water heater tank is full?

Open a hot-water faucet after connecting the RV to water or turning on the water pump. The tank is generally full when water flows steadily from the hot faucet without sputtering air.

Make sure the water heater bypass valves are in the normal operating position before filling the tank.

31. What is an RV water heater bypass valve?

The bypass system allows water to flow around the water heater instead of through it. It is primarily used during winterization so the water heater can be drained without filling the entire tank with RV antifreeze.

Depending on the RV, the system may use one, two or three valves.

Incorrect bypass-valve positions are one of the most common reasons an RV has no hot water after being removed from storage.

32. Why is my RV water heater not working after winterization?

After winterization, check for:

  • Bypass valves still in the winter position

  • A closed cold-water inlet valve

  • A stuck outlet check valve

  • An empty water heater tank

  • Disconnected electrical wiring

  • A removed drain plug or anode rod

  • Air trapped in the propane line

  • Freeze damage

  • A switch or circuit breaker left off

Confirm that the tank is full before turning on propane or electric heat.

33. How do I drain an RV water heater?

The basic process for a tank-style RV water heater is:

  1. Turn off the propane and electrical power.

  2. Allow the water to cool.

  3. Turn off the water supply.

  4. Open a hot-water faucet to relieve pressure.

  5. Open the pressure relief valve.

  6. Remove the drain plug or anode rod.

  7. Allow the tank to drain completely.

Suburban water heaters commonly drain through the anode-rod opening. Dometic and Atwood models commonly use a nylon drain plug.

34. How often should I flush my RV water heater?

An RV water heater should generally be drained and flushed at least once per year. More frequent flushing may be needed when the RV is used heavily or connected to hard water.

Flushing removes sediment and mineral deposits that can cause odors, noise, reduced efficiency and premature component failure.

35. How do I winterize an RV water heater?

A tank-style RV water heater is normally winterized by:

  • Turning off propane and electrical power

  • Allowing the water to cool

  • Draining the tank

  • Flushing out sediment

  • Placing the bypass valves in the winter position

  • Winterizing the remaining RV plumbing system

Tankless water heaters must also be completely drained. Freeze-protection features may not protect an unpowered or stored RV.

Always follow the procedure for the specific water heater model.

36. Does an RV tankless water heater need to be winterized?

Yes. Tankless RV water heaters contain small water passages, valves and heat-exchanger tubing that can be damaged when trapped water freezes.

Built-in freeze protection generally requires electrical power and may only protect the unit under specific conditions. It is not a substitute for draining and winterizing the water heater before storage.

37. Can RV antifreeze go inside the water heater?

When an RV has a functioning bypass system, the water heater is generally drained and bypassed so the tank does not need to be filled with antifreeze.

RV antifreeze can accelerate deterioration of a Suburban anode rod. Tankless winterization procedures vary by model, so the manufacturer’s instructions should be followed.

38. Why is my RV water heater leaking after freezing weather?

Water expands as it freezes and can crack or split:

  • Storage tanks

  • Tankless heat exchangers

  • Water valves

  • Flow sensors

  • Check valves

  • Mixing valves

  • Plastic fittings

  • Plumbing connections

The system may not leak until it is refilled and pressurized. Inspect the exact source before deciding whether an individual component or the complete water heater must be replaced.

39. Should I repair or replace my RV water heater?

Repair may be the best choice when the problem is limited to a replaceable component such as:

  • A control board

  • A thermostat

  • A heating element

  • A burner

  • An igniter

  • A gas valve

  • A flow sensor

  • A pressure relief valve

Complete replacement may make more sense when:

  • The tank is leaking

  • The heat exchanger is severely damaged

  • Multiple expensive components have failed

  • Freeze damage is extensive

  • The original model is obsolete

  • Replacement parts are no longer available

  • The owner wants to convert to a tankless system

The correct choice depends on the water heater’s age, condition and replacement-part availability.

40. Where can I buy Suburban, Dometic and Girard RV water heater parts?

RVWaterHeaterGuys.com specializes in complete RV water heaters and replacement parts for Suburban, Dometic, Atwood and Girard models.

Customers can shop by manufacturer, model number or part category to find control boards, thermostats, heating elements, burners, igniters, gas valves, tanks, sensors, heat exchangers and other model-specific components.

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